|
Search of All Forums Enter your search criteria. Click here for tips on using our search |
For Sale Ads |
1: Tube DIY Asylum, RE: What are people using for their websites (0.00)
Posted by VoltSecond on 2021-06-24, 23:04:39 (72.222.192.214)
I haven't worked in hexadecimal and machine language since before 1978. I wore the enter key out on the keypad and soldered a telegraph key to it and used my foot to hit enter. Kansas city standard i .......
2: Tube DIY Asylum, What are people using for their websites (0.00)
Posted by VoltSecond on 2021-06-20, 13:23:36 (72.222.192.214)
What are people using for their websites? For my old website I used Mozilla composer (now SeaMonkey) to write it and a simple FTP protocol to upload. I'd like to get my VoltSecond site back up and sta .......
3: Tube DIY Asylum, RE: Volume pot recommendation (0.00)
Posted by VoltSecond on 2021-06-20, 13:12:18 (72.222.192.214)
I would go with an external switched attenuator in the RCA line. .......
4: Tube DIY Asylum, RE: HV Supply Wish List (0.00)
Posted by VoltSecond on 2021-01-11, 20:00:44 (72.222.192.214)
My trick To pull a SMT resistor is I put excess solder on both ends and tap the iron back and forth between the two solder joints. After about 3 taps I get both ends liquid at the same time and it com .......
5: Tube DIY Asylum, RE: HV Supply Wish List (0.00)
Posted by VoltSecond on 2021-01-11, 19:56:48 (72.222.192.214)
Easier, but what's life without solder slinging! -Volt .......
6: Tube DIY Asylum, RE: HV Supply Wish List (0.00)
Posted by VoltSecond on 2021-01-11, 19:54:36 (72.222.192.214)
We could trim lower. A couple parts in the neg bias supply would have to be changed. -Volt .......
7: Tube DIY Asylum, RE: MF grid for grid stoppers- a retrovert perspective (0.00)
Posted by VoltSecond on 2021-01-10, 16:40:10 (72.222.192.214)
Hey Paul. Drop me an email on my old Hotmail account. -Volt .......
8: Tube DIY Asylum, HV Supply Wish List (0.00)
Posted by VoltSecond on 2021-01-10, 16:37:58 (72.222.192.214)
I had a friend contact me during Christmas break about making a switched mode HV power supply for a tube amp. Since I wasn't going anywhere or doing much because of COVID. I had a little time to play, .......
9: Tube DIY Asylum, Yes, I'm a round. (0.00)
Posted by VoltSecond on 2021-01-10, 14:31:37 (72.222.192.214)
I haven't been active in the forums in years. I'm hoping to change that soon. I only check my email once a quarter at this point. When I have time, I've mostly been playing with headphone amps. The be .......
10: Tube DIY Asylum, RE: you could biamp (Dr.P) (0.00)
Posted by VoltSecond on 2021-01-10, 14:12:45 (72.222.192.214)
Don't forget about Damped Resonance Parafeed. The RC across the parafeed cap gives us a free variable to adjust. It doesn't do a lot into some resistive loads, but when the reactance kicks in, it can .......
11: Tube DIY Asylum, RE: 30-60 Second Relay ? (0.00)
Posted by VoltSecond on 2021-01-02, 23:35:37 (72.222.192.214)
This may help. A simple place to put a solid state relay is in the ground connection on the HV output. -Volt .......
12: Tube DIY Asylum, RE: Power transformer secondary snubbing questions. (0.00)
Posted by VoltSecond on 2014-12-29, 16:14:31 (68.228.232.169)
My questions are: * Will all power transformers ring in response to rectifier spikes? [ Yes. All of them will. But some of them won't ring enough that we care.] If not, what characteristics does a po .......
13: Tube DIY Asylum, Been there done that! (0.00)
Posted by VoltSecond on 2014-12-29, 15:56:58 (68.228.232.169)
I haven't tried shut regulation at 180W. But I've blown the lids off of large capacitors and stuck them in the ceiling tiles! I'm very cautious about transient voltage and transient power ratings late .......
14: Tube DIY Asylum, Yes SCRs are quite noisy. Standard cap input is too. (0.00)
Posted by VoltSecond on 2014-12-25, 16:42:01 (68.228.232.169)
Yes SCRs are quite noisy. Standard cap input rectification is noisy too (it inherently chops at 120Hz -- Two high current pulses per cycle.) If a filament winding is used off the same transformer as t .......
15: Tube DIY Asylum, High Voltage Pre-Regulator (0.00)
Posted by VoltSecond on 2014-12-24, 22:05:39 (68.228.232.169)
I was discussing high voltage pre-regulators with a friend and wanted to bounce the conversation off of the forum here. The pre-regulator operates by gating the rectified 60Hz (120 hz) waveform on and .......
16: General Asylum, I'd open it up to see what failed (0.00)
Posted by VoltSecond on 2014-06-13, 22:56:24 (72.208.65.252)
If the supply caps probably died, I'd replace every electrolytic on the card. If the PWB is charred, I'd not try to fix it. .......
17: Inmate Central, RE: Recommend "Audiophile grade" ballpoint pen? (0.00)
Posted by VoltSecond on 2014-02-23, 20:42:13 (72.208.65.252)
I used to like the Sharpie Liquid Mechanical Pencils. The feel and ink quality isn't top notch, but it is erasable for 1 day and then becomes permanent. [img]http://www.sharpie.com/enUS/PublishingImag .......
18: Speaker Asylum, I got the A2s for Mrs. Volt. Thanks. (0.00)
Posted by VoltSecond on 2014-01-06, 22:57:30 (72.208.65.252)
Thanks for the suggestion. I got the A2s for Mrs. Volt. She's happy and I definitely can live with these speakers on her computer desk. Fresh out of the box, the A2's highs are a little soft. This mos .......
19: Speaker Asylum, Thanks (nt) (0.00)
Posted by VoltSecond on 2013-11-30, 14:15:25 (72.208.65.252)
. .......
20: Speaker Asylum, Computer Speakers for Mrs. Volt (0.00)
Posted by VoltSecond on 2013-11-29, 22:53:17 (72.208.65.252)
Mrs. Volt is getting a new computer of Christmas. My work schedule isn't going to let me have enough time to go research this myself so I need a recommendation for a small set of computer speakers. P .......
21: SET Asylum, Thanks for the feedback (nt) (0.00)
Posted by VoltSecond on 2013-10-07, 20:31:05 (72.208.65.252)
. .......
22: SET Asylum, DrP can help with the low frequency resonance in Parafeed (0.00)
Posted by VoltSecond on 2013-10-05, 23:02:34 (72.208.65.252)
DrP, Damped Resonance Parafeed It's more than an excellent soft drink. .......
23: SET Asylum, Why have a preamp? (0.00)
Posted by VoltSecond on 2013-08-26, 21:51:55 (72.208.65.252)
RE The need for a preamp: I've seen audio amps that could not reach full power without a preamp in front of them. Those amps were quiet with very long runs of cable between the preamp and the amps. Th .......
24: MagneQuest/Peerless Forum, Tre's right. You loose the athode bypass cap effects (0.00)
Posted by VoltSecond on 2013-08-04, 18:31:31 (72.208.65.252)
With the parafeed returned to power ground, the cathode capacitor has to support the signal current + parasitic currents. With the parafeed returned to the cathode, the cap only has to support parasit .......
25: High Efficiency Speaker Asylum, RE: And remember... (0.00)
Posted by VoltSecond on 2013-06-12, 20:50:14 (72.208.65.252)
He should of worn chem lab glasses and shown a piece of wire embedded in them. I know he was putting on a fun show just for laughs, but I've actually worked with people that bad and that bad on a dail .......
26: MagneQuest/Peerless Forum, surgery on my right hand. . . (0.00)
Posted by VoltSecond on 2013-03-20, 21:07:22 (72.208.65.252)
Stacking cores with your toes must be a challenge. .......
27: MagneQuest/Peerless Forum, Headphones (0.00)
Posted by VoltSecond on 2013-01-06, 18:56:17 (72.208.65.252)
If you have a 1W into 8 ohm power amp, it will drive the headphone directly. I would put a 32 ohm ballast resistor across the power output to avoid possible low frequency issues while driving higher t .......
28: SET Asylum, So true! . . .all three legs need to be good. (0.00)
Posted by VoltSecond on 2012-12-24, 21:12:35 (72.208.65.252)
The guy in the cube next to me at work is fighting a circuit. He is quickly finding out that "if you want to sit on the stool, all three legs (parts, layout, design) need to be good enough." ::: TOPIC .......
29: MagneQuest/Peerless Forum, Forget stockpiling gold for a recession, (0.00)
Posted by VoltSecond on 2012-12-12, 20:25:42 (72.208.65.252)
Forget stockpiling gold for a recession, stockpile MQ transformers. .......
30: High Efficiency Speaker Asylum, Take care of yourself (nt) (0.00)
Posted by VoltSecond on 2012-12-03, 20:27:52 (72.208.65.252)
. .......
31: High Efficiency Speaker Asylum, Regulate that supply for the switching amp! (0.00)
Posted by VoltSecond on 2012-10-27, 23:41:52 (68.3.229.18)
Many switching amps need a clean, stiff power supply. I've taken apart one of them and looked at the chips for several. Before feedback is applied the circuit gives: Vout = Audio Signal * Gain factor .......
32: MagneQuest/Peerless Forum, I'm thinking low nickel ! (0.00)
Posted by VoltSecond on 2012-10-14, 21:24:45 (68.3.229.18)
High initial perm without giving up too much gauss or too much high frequency loss. .......
33: MagneQuest/Peerless Forum, You're Welcome (nt) (0.00)
Posted by VoltSecond on 2012-10-06, 21:17:41 (68.3.229.18)
. .......
34: MagneQuest/Peerless Forum, DR-P and snubbers (0.00)
Posted by VoltSecond on 2012-10-06, 21:06:18 (68.3.229.18)
I'm glad what you've tried panned out. DR-P can help with sub-sonic ripple and what it does to the bias point in the iron. Since the DR-P cap has a resistor in series with it, first order, the main ca .......
35: MagneQuest/Peerless Forum, Idea 2 (0.00)
Posted by VoltSecond on 2012-10-04, 00:01:53 (68.3.229.18)
Snub the filament windings (try 1uF) Make the 6.3V reg use schottky rectifiers. .......
36: MagneQuest/Peerless Forum, Ideas 1 (0.00)
Posted by VoltSecond on 2012-10-03, 23:59:51 (68.3.229.18)
The above picture is an example only, not the correct values. Try taking the BCP 16 to the cathode of the 6sn7. This has a side benefit of allowing the 1000uF cap to drop to be a film capacitor. If yo .......
37: MagneQuest/Peerless Forum, RE: Grid Chokes (0.00)
Posted by VoltSecond on 2012-10-02, 21:10:19 (68.3.229.18)
Is the CCS operating with >20V across it? Many CCS designs do not like less than 20V (static) across them. Strangely this may help: Put a 1K to 10K resistor in the grid of the 6C19P. It isolates the g .......
38: High Efficiency Speaker Asylum, Plans? (0.00)
Posted by VoltSecond on 2012-09-12, 21:43:01 (68.3.229.18)
Is there a 12" version of this that works well? .......
39: MagneQuest/Peerless Forum, He lived life. (0.00)
Posted by VoltSecond on 2012-06-10, 10:07:28 (68.3.229.18)
He lived life. Too many of us forget to do that. He'll be missed. .......
40: High Efficiency Speaker Asylum, Other ideas (0.00)
Posted by VoltSecond on 2012-03-20, 21:04:43 (68.3.229.18)
I haven't played with the Tripp Lite isolator. Some computer grade line filters improve RF noise at the expense of making audio noise worse. Others do quite well at blocking both audio and RF noise. T .......
41: High Efficiency Speaker Asylum, It is also easy for power line noise to get in through the preamp. (0.00)
Posted by VoltSecond on 2012-03-19, 17:13:57 (68.3.229.18)
It is also easy for power line noise to get in through the preamp. .......
42: High Efficiency Speaker Asylum, Batteries supply a lot of low frequency current. (0.00)
Posted by VoltSecond on 2012-03-19, 17:10:51 (68.3.229.18)
Batteries can supply a lot of low frequency current; however, their impedance goes up at higher frequencies. The higher high frequency impedance is why the capacitor across them helps. .......
43: High Efficiency Speaker Asylum, I'd suspect temperature variation, not just line noise (0.00)
Posted by VoltSecond on 2012-03-18, 21:48:17 (68.3.229.18)
I'd suspect temperature, not just line noise. The Magnepan may have low resistance at DC. This can make the amp heat up from it's DC offset and lead to distortion. If you cap couple the amp to the spe .......
44: General Asylum, It is a retro Edison bulb. . .more (0.00)
Posted by VoltSecond on 2012-02-21, 19:32:24 (68.3.229.18)
I found a retro decorative bulb at Home Depot. It sort-of looks like this. This is the first picture google found that looked right. However, the bulb's filaments were too white to look at with the 12 .......
45: General Asylum, Wow. $99 for a diode. (0.00)
Posted by VoltSecond on 2012-02-14, 20:08:43 (68.3.229.18)
Wow. Thanks. A $99 diode. What I want to do is to dim a decorative bulb from white to a dimmer yellow in a hallway. A pair of three way dimmers will be cheaper. .......
46: General Asylum, Incandescent Wattage Reducer (0.00)
Posted by VoltSecond on 2012-02-14, 19:17:15 (68.3.229.18)
Google is failing me. I'm looking for those old screw in incandescent wattage reducers they made for lamp sockets. They were a bit thicker than a quarter and had a diode in them so the bulb only saw 1 .......
47: MagneQuest/Peerless Forum, RE: transformer (0.00)
Posted by VoltSecond on 2011-12-27, 21:08:25 (68.3.229.18)
It is difficult to answer these questions because they come without any context. >> 1.If i apply sine weighted waveform ( PWM generated)to secondary shorted transformers which frequency will be respon .......
48: Radio Road, Has anyone built the Gakken Vacuum Tube Radio Kit? (0.00)
Posted by VoltSecond on 2011-12-23, 10:10:54 (68.3.229.18)
Has anyone built the Gakken Vacuum Tube Radio Kit? I'm looking for something to get MilliVolt (my 7 year old) interested in building electronics. .......
49: High Efficiency Speaker Asylum, Where are the plans for that one? (0.00)
Posted by VoltSecond on 2011-11-10, 14:53:23 (68.3.229.18)
Where are the plans for that Karlson? That one looks within my wood working skills. .......
50: High Efficiency Speaker Asylum, Biamp or go to 10W (0.00)
Posted by VoltSecond on 2011-10-02, 19:34:44 (68.3.229.18)
After living with a step attenuator, I agree it takes 8-10X the ower to sound twice as loud. If 1W isn't doing it, you need 10X more. Another way around this is to bi-amp. Solid state on the woofer an .......
51: MagneQuest/Peerless Forum, Would a high voltage delay help? (0.00)
Posted by VoltSecond on 2011-09-09, 21:08:04 (68.3.229.18)
Would a 15 second long high voltage delay help? I'd use plastic transistors next time instead of metal can ones. Turn the heaters on first. Some time ago someone posted a two switch method to do this .......
52: MagneQuest/Peerless Forum, negative bias supply (0.00)
Posted by VoltSecond on 2011-09-07, 21:57:35 (68.3.229.18)
This will make a negative supply. I would put the 100H choke in the negative lead. It will work where it is, but with the choke in the negative lead, the noise from the bridging capacitance in the tra .......
53: High Efficiency Speaker Asylum, The ultra fast diodes were discrete diodes (0.00)
Posted by VoltSecond on 2011-09-07, 20:44:27 (68.3.229.18)
The ultra fast Mod were TO-220 ultrafast diodes mounted to a deburred metal plate (for heatsinking) with insulating washers and TO-220 insulator. .......
54: MagneQuest/Peerless Forum, What is it doing that you do not like? (0.00)
Posted by VoltSecond on 2011-09-07, 20:39:52 (68.3.229.18)
. .......
55: High Efficiency Speaker Asylum, Rectifiers in the DH200 (0.00)
Posted by VoltSecond on 2011-09-06, 19:40:12 (68.3.229.18)
One of the guys in the local audio club changed out just the diode bridge rectifiers with ultra fast diodes and it really cleaned up the sound of the DH-200. The same MOD would also work in the DH-500 .......
56: MagneQuest/Peerless Forum, Use the RH-40. I missed that you wanted a drop-in. (0.00)
Posted by VoltSecond on 2011-08-30, 20:29:50 (68.3.229.18)
Use the 40. .......
57: MagneQuest/Peerless Forum, 6v6 Triode (0.00)
Posted by VoltSecond on 2011-08-29, 21:27:50 (68.3.229.18)
With a 5K load, I'd try 260V 30mA bias on a RH-40. You'd get about 1.3W out and be able to handle small dips in the speaker impedance. .......
58: MagneQuest/Peerless Forum, The Robin Hood series is optimized for single ended use (0.00)
Posted by VoltSecond on 2011-08-28, 18:24:58 (68.3.229.18)
The Robin Hood series is optimized for single ended use. .......
59: General Asylum, Bob Pease is no longer with us. (0.00)
Posted by VoltSecond on 2011-06-20, 19:58:09 (68.3.229.18)
Bob Pease passed away in a car accident last weekend.. I had a quick chat with Bob once while he was waiting for a flight. This man really knew his stuff. It may have been the only time in my life I u .......
60: General Asylum, That is correct. The 2nd ground . . . (0.00)
Posted by VoltSecond on 2011-05-07, 20:35:14 (68.3.229.18)
Yes, you only want one ground node in the house. The 2nd ground rod I was referring to was where in the same breaker box as the first ground rod, you run another heavy wire to a second ground rod and .......
61: General Asylum, Line transients occur for many reasons. (0.00)
Posted by VoltSecond on 2011-05-05, 20:29:38 (68.3.229.18)
I'm more concerned about the transients generated by the power company when the power goes on and off every couple months and the neighborhood goes dark. This is not to mention the spikes on the power .......
62: General Asylum, Get a dedicated line and . . . (0.00)
Posted by VoltSecond on 2011-05-02, 21:08:34 (68.3.229.18)
2. Install a second ground rod about 6 foot from your existing one. If you live in a dry state (Arizona) put a drip on your ground rod(s). Check to make sure your existing ground rod hasn't rotted a .......
63: Speaker Asylum, EE times articles by Floyd Toole (0.00)
Posted by VoltSecond on 2011-04-28, 20:34:57 (68.3.229.18)
I ran across the link below recently and thought I'd share it. It has some useful information in it. .......
64: SET Asylum, You'll want a resistor (0.00)
Posted by VoltSecond on 2011-02-12, 19:25:08 (68.3.229.18)
You'll want a resistor between the source of the FET and the grid of the tube to keep the FET happy. Try around 1Kohm. You may also want to try a high voltage transistor here too. The transistor will .......
65: General Asylum, Decent story on Precision-Versus-Accuracy (0.00)
Posted by VoltSecond on 2011-01-10, 20:29:41 (68.3.229.18)
I ran across a cecent story on Precision-Versus-Accuracy using a rifle as the example. .......
66: MagneQuest/Peerless Forum, What is the test to tell if a metal is platinum? (0.00)
Posted by VoltSecond on 2011-01-01, 10:25:05 (68.3.229.18)
I'm curious, what is the test to tell if a metal is platinum? .......
67: SET Asylum, 16 twisted pairs of Cat 5 cable. (0.00)
Posted by VoltSecond on 2010-11-21, 19:38:08 (68.3.229.18)
Multiple cat 5 cables in parallel sound good to me. For SET amplifiers, you can get by with a cable that has high capacitance like multiple cat 5 twisted pairs in parallel. I'd be cautious using this .......
68: MagneQuest/Peerless Forum, A good transformer works magic. (0.00)
Posted by VoltSecond on 2010-11-16, 19:26:54 (68.3.229.18)
A good transformer turns unbalanced interconnect performance into balanced performance by breaking the ground loops from preamp to power amp. .......
69: SET Asylum, Will it drive a headphone? (0.00)
Posted by VoltSecond on 2010-10-20, 18:48:31 (68.3.229.18)
Will it drive a headphone directly or through a transformer (possibly even a TVC?) .......
70: MagneQuest/Peerless Forum, Where did you get the top plate marked? (0.00)
Posted by VoltSecond on 2010-09-14, 20:01:45 (68.3.229.18)
Did you use front panel express? .......
71: High Efficiency Speaker Asylum, Is it under warantee? If not, consider a few mods. (0.00)
Posted by VoltSecond on 2010-09-11, 19:21:28 (68.3.229.18)
It is easy for power supply noise to get in through the filaments and high voltage winding. If you're willing to mod it: Unplug the amp and verify all the caps have discharged to My standard mod list .......
72: Tweakers' Asylum, That should work. Thanks. (nt) (0.00)
Posted by VoltSecond on 2010-08-30, 20:44:49 (68.3.229.18)
. .......
73: High Efficiency Speaker Asylum, RE: Denon AH-D7000 headphones (0.00)
Posted by VoltSecond on 2010-08-30, 20:36:40 (68.3.229.18)
I'd buy something less expensive so if TSA, customs, the person in the seat next to you breaks them, it isn't as big of a loss. When walking, leave them at the hotel (in the safe if you get the Denon) .......
74: MagneQuest/Peerless Forum, The Panasonic at Costco does not have a headphone jack (0.00)
Posted by VoltSecond on 2010-08-28, 18:47:30 (68.3.229.18)
The Panasonic at Costco does not have a headphone jack. HOWEVER, the 4 pack of Panasonics at Costco and one spare phone with a headphone jack costs the same as the set of 4 Panasonics at Fry's Electro .......
75: Tweakers' Asylum, I forgot about those. (0.00)
Posted by VoltSecond on 2010-08-28, 17:38:09 (68.3.229.18)
I used them 30 years ago. I forgot about them. They may work on Hammertone. .......
76: Tweakers' Asylum, How do you get good looking labels on a project box? (0.00)
Posted by VoltSecond on 2010-08-28, 15:05:15 (68.3.229.18)
I take any hints or advise you have to give on how to mark a die cast metal box. I'm finishing a home project (my first since MilliVolt was born) and for the first time I'd like to mark the knobs on a .......
77: General Asylum, I set up a second account at my Credit Union for Paypal (0.00)
Posted by VoltSecond on 2010-07-31, 15:13:14 (68.3.229.18)
I set up a second account at my Credit Union for PayPal to reduce my risk. I purposely did not set this account up to automatically draw from my main account. I have not had any bad experiences with .......
78: General Asylum, I'll second the ATH-50M ($99 on Amazon) (0.00)
Posted by VoltSecond on 2010-07-25, 20:31:42 (68.3.229.18)
I'll second the ATH-50M. They took a couple weeks of 4 hours/day to fully break in. They offer some outside sound isolation and there isn't a lot of leakage so you won't be bothering others. A portabl .......
79: General Asylum, What software did you use for your sound card spectrum analyzer? (0.00)
Posted by VoltSecond on 2010-07-24, 14:13:14 (68.3.229.18)
What software did you use for your sound card spectrum analyzer? I haven't played with those yet. .......
80: General Asylum, I've used the "lunch box" scopes at work. (0.00)
Posted by VoltSecond on 2010-07-23, 20:53:20 (68.3.229.18)
I've used the Tek "lunch box" scopes at work. The Tek “digital phosphor” is nice. They do 99% of what a Tek 475 can and they'll save the data to disk/ USB. However, I'd like more bits and a better FFT .......
81: General Asylum, USB Oscilloscopes (0.00)
Posted by VoltSecond on 2010-07-23, 12:24:32 (68.3.229.18)
Does anyone have feedback on the "clever scope" or other USB / ethernet scope for Audio Measurement and circuit debug? My Tek 465 smells like dying caps and I'm considering going digital. If I go thi .......
82: SET Asylum, Swapping leads on a two prong plug shouldn't cause sparks. (0.00)
Posted by VoltSecond on 2010-07-03, 19:34:39 (68.3.229.18)
Just to double check, swapping leads on a two prong plug shouldn't cause sparks to come and go. If this happens, something on the 115V side is touching the secondary side. However, if hot and safety .......
83: SET Asylum, Call Jeffrey at Experiance Music (0.00)
Posted by VoltSecond on 2010-05-15, 17:17:07 (68.3.229.18)
Jeffery occasionally does custom work too. .......
84: High Efficiency Speaker Asylum, Take out the windows and put them outside the house. (0.00)
Posted by VoltSecond on 2010-05-11, 19:41:13 (68.3.229.18)
Take out the windows and put them outside the house. Then find a way to weather proof them. .......
85: MagneQuest/Peerless Forum, RE: Cheap does not equal inexpensive. (0.00)
Posted by VoltSecond on 2010-05-09, 21:08:40 (68.3.229.18)
I'm glad you enjoyed it. Also, I thought the mouse looked like the mouth of a shark with the bulls and people running into it. .......
86: MagneQuest/Peerless Forum, Cheap does not equal inexpensive. (0.00)
Posted by VoltSecond on 2010-05-06, 23:55:44 (68.3.229.18)
Traditionally, many buy the cheapest they can find. Cheap does not equal inexpensive. If you need quality, buy quality. If you want performance, buy performance. If you want cheap, read the mouse pa .......
87: MagneQuest/Peerless Forum, Any advise for a new web host? (0.00)
Posted by VoltSecond on 2010-03-27, 17:58:21 (68.3.229.18)
My friend wants to close this site. I only use basic HTML commands. .......
88: MagneQuest/Peerless Forum, Keep the grid stop resistors (0.00)
Posted by VoltSecond on 2010-02-25, 20:41:38 (68.3.229.18)
Keep the grid stop resistors. They are to damp high frequency oscillations. .......
89: MagneQuest/Peerless Forum, I'm surprised (0.00)
Posted by VoltSecond on 2010-02-23, 18:49:27 (68.3.229.18)
I'm surprised with the choke in the same physical location moving the resistor changed the hum level. This should have only affected the highs. .......
90: MagneQuest/Peerless Forum, Try swapping the position of R6 and L1. (0.00)
Posted by VoltSecond on 2010-02-22, 19:44:53 (68.3.229.18)
Try swapping the position of R6 and L1. Sometimes the choke likes to see a low impedance to ground. .......
91: MagneQuest/Peerless Forum, If Q1 is getting hot (0.00)
Posted by VoltSecond on 2010-02-17, 18:28:06 (68.3.229.18)
Sand doesn't like heat. If Q1 is getting hot, you can put a resistor from Drain to Source that conducts ~30% of the current, it will cool Q1 off and should not mess the performance up. I'd like a 32 o .......
92: MagneQuest/Peerless Forum, RE: snowmageddon... but it's kind of neat (0.00)
Posted by VoltSecond on 2010-02-15, 10:03:07 (68.3.229.18)
Make sure the mu metal is re-annealed after it is formed, bent etc. When mu metal is "worked", its shielding properties drop to be less than steel. I've had some luck with double shielding (a faraday .......
93: High Efficiency Speaker Asylum, Instead of veneer, use speaker grill cloth. (0.00)
Posted by VoltSecond on 2010-02-14, 19:41:57 (68.3.229.18)
Instead of veneer, use speaker grill cloth to get the WAF up. Possibly clamp the outside edges with something like furring strips to hide the ragged edges. .......
94: High Efficiency Speaker Asylum, How about building a frame. . . (0.00)
Posted by VoltSecond on 2010-02-14, 13:17:32 (68.3.229.18)
How about building a open frame with wood and then using 1" felt for the walls. Possibly hold the felt in place with vinyl coated chicken wire on both sides of each wall. .......
95: MagneQuest/Peerless Forum, Send me Asylum mail and I'll send you the old version. (0.00)
Posted by VoltSecond on 2010-02-04, 20:06:59 (68.3.229.18)
. .......
96: MagneQuest/Peerless Forum, I'll look for it. (0.00)
Posted by VoltSecond on 2010-02-03, 20:42:57 (68.3.229.18)
The bigger problem is remembering the password to my website. .......
97: MagneQuest/Peerless Forum, Glazed eyes are a recurring problem (0.00)
Posted by VoltSecond on 2010-02-02, 19:24:19 (68.3.229.18)
Download the excel spreadsheet and you can play with the curves. .......
98: MagneQuest/Peerless Forum, Take the primary of the transformer (0.00)
Posted by VoltSecond on 2009-12-03, 20:23:48 (68.3.229.18)
Take the primary of the transformer to the cathode of the output tube. This keeps the current in the regulator tube constant as the music plays. .......
99: Tube DIY Asylum, Has anyone use the Elliot Sound Volume control? (0.00)
Posted by VoltSecond on 2009-11-07, 19:43:06 (68.3.229.18)
Has anyone use the Elliot Sound Volume linear pot with a resistor volume control? .......
100: Bottlehead Forum, RE: Headphones (0.00)
Posted by VoltSecond on 2009-10-13, 22:06:00 (68.3.229.18)
My current favorite is the ATH-M50. Sealed over the ears. I can listen while MilliVolt watches Disney. A tiny bit of cross feed helps with the "in head" problem. .......
101: MagneQuest/Peerless Forum, 2A3 5K load (0.00)
Posted by VoltSecond on 2009-09-21, 20:33:08 (68.3.229.18)
260V Plate-Cathode with 40mA bias current ~53V cathode to ground should give a clean 2-3W output. (Cathode resistor of 1.3K, plate voltage of 313V) The plate will be at 10.4W so the tube will last a l .......
102: MagneQuest/Peerless Forum, What is a good mid-priced volume control these days? (0.00)
Posted by VoltSecond on 2009-09-18, 20:42:49 (68.3.229.18)
What is a good mid-priced volume control these days? .......
103: MagneQuest/Peerless Forum, RE: They all seem to be 5K (0.00)
Posted by VoltSecond on 2009-09-18, 20:30:32 (68.3.229.18)
I like the sound of 5K on the plate. It is a little tighter than 2.5k, but not too tight. .......
104: MagneQuest/Peerless Forum, Did you look at Mike's Robin Hood line? (0.00)
Posted by VoltSecond on 2009-09-16, 20:29:44 (68.3.229.18)
http://www.magnequest.com/products.htm .......
105: Bottlehead Forum, OSHA (0.00)
Posted by VoltSecond on 2009-09-01, 20:19:04 (68.3.229.18)
Someone recently said OSHA put the "safe" limit at 50V. .......
106: MagneQuest/Peerless Forum, If cost is no object, use a seperate filament Xfmr (0.00)
Posted by VoltSecond on 2009-08-17, 21:21:27 (68.3.229.18)
Sharing a B+ winding and a filament winding introduces distortion and noise on to the filament winding. This distortion and noise can be filtered out, but a seperate Xfmr with a smaller amount of filt .......
107: High Efficiency Speaker Asylum, Keep both amps (0.00)
Posted by VoltSecond on 2009-08-06, 21:24:28 (68.3.229.18)
I keep my old amps and fire the old ones up occasionally. .......
108: Bottlehead Forum, T-amp really benefits from regulated rails. (0.00)
Posted by VoltSecond on 2009-08-01, 15:31:34 (68.3.229.18)
T-amp really benefits from regulated rails. Even using a simple LM7812 and LM7912 does the trick (with a big cap on the +/- 12V) My Tamp didn't have the heatsink under the part properly soldered down. .......
109: Bottlehead Forum, You may be able to run with the power on (0.00)
Posted by VoltSecond on 2009-07-14, 20:29:47 (68.3.229.18)
You may be able to run with the power on. The 9V nicads would act as a shunt regulator. .......
110: Bottlehead Forum, RE: Charging.... (0.00)
Posted by VoltSecond on 2009-07-13, 20:00:16 (68.3.229.18)
My buddy who is into batteries says the rechargable alkalines don't last long. If you are trickle charging, the NiCads are supposed to be far more tolerant of trickle charging than NiMH Make sure you .......
111: Bottlehead Forum, RE: Charging.... (0.00)
Posted by VoltSecond on 2009-07-10, 22:15:35 (68.3.229.18)
As long as the charge current is kept low (0.03 * C ) many batteries can be trickle charged in series for long durations. It is when the charge current gets high, you shouldn't charge them in series. .......
112: MagneQuest/Peerless Forum, Attach the bottom of C6 to the top C5 (0.00)
Posted by VoltSecond on 2009-06-29, 20:05:25 (68.3.229.18)
Connect the parafeed cap to the cathode of the output tube. It sounds much better that way. The parafeed cap can ring higher than the plate. I would rate the coupling cap for at least 1.4 times the pl .......
113: High Efficiency Speaker Asylum, I use them in my office. (0.00)
Posted by VoltSecond on 2009-06-22, 20:51:49 (68.3.229.18)
They do need to be placed near a wall. You may want a sub. .......
114: High Efficiency Speaker Asylum, tripath class D amp (0.00)
Posted by VoltSecond on 2009-05-21, 22:05:51 (68.3.231.220)
The T-Amp really benefits from a clean regulated power supply. The solder joint from the chip's heatsink frame to the PWB ground plane wasn't very good in my T-amp. After I resoldered it and filled al .......
115: Bottlehead Forum, My 100x only go to 1200V pk (0.00)
Posted by VoltSecond on 2009-05-17, 14:32:02 (68.3.231.220)
The newer 1000x probes I've seen aren't very good. You can wave your hand over them and see a significant change in the waveform. The old freon filled ones didn't do that. Play safe and play longer! D .......
116: Bottlehead Forum, Maybe have a bunch of "regionals" and recommend 3 for RMAF? (0.00)
Posted by VoltSecond on 2009-05-11, 21:19:34 (68.3.231.220)
I haven't made it to RMAF yet either. Fun events always tend to fall on a work commitment weekend. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twic .......
117: Bottlehead Forum, Have you considered make this part of the 2010 RMAF? (0.00)
Posted by VoltSecond on 2009-05-09, 20:27:59 (68.3.231.220)
Have you considered make this contest part of the 2010 RMAF? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .R .......
118: Bottlehead Forum, Oversize it a bit. (0.00)
Posted by VoltSecond on 2009-05-04, 20:20:30 (68.3.231.220)
Most transformers are rated into a resistive load. This means that yes, the filament is easy. Add up the currents with 20% margin for line and part variation and you are done. The B+ is harder. The rm .......
119: Bottlehead Forum, Shipping (0.00)
Posted by VoltSecond on 2009-04-27, 21:42:09 (68.3.231.220)
For those of us who don't know if they can make it in person, can we ship our entry (paying postage both ways?) Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and mea .......
120: Bottlehead Forum, Ditto (0.00)
Posted by VoltSecond on 2009-04-22, 21:12:00 (68.3.231.220)
Check to make sure the switch profile has not been changed to default or something else. Costco has good deals on USB disks. I back up most of my files onto external drives. Play safe and play longer! .......
121: Bottlehead Forum, Nice 9Vs (0.00)
Posted by VoltSecond on 2009-04-09, 17:13:16 (68.3.231.220)
If you cut the 9V clip in half, you can stack quite a few 9V in series and use 1 battery clip. I see a run on the 9V batteries in bulk at Costco (B-n-L). ~480 mAh or 120 hrs at 4 mA Play safe and pla .......
122: Bottlehead Forum, RE: Micheal Hedges... (0.00)
Posted by VoltSecond on 2009-03-23, 20:05:26 (68.3.231.220)
The first time Mrs. Volt and I saw Michael Hedges he was an opening act for another Windham Hill group at the local Symphony Hall. No one we knew had ever heard of him. In walks this young man in bea .......
123: MagneQuest/Peerless Forum, RE: C-core radiation pattern (0.00)
Posted by VoltSecond on 2009-02-20, 20:02:26 (68.3.231.220)
Wrap an imaginary string under each exposed coil and tie a knot in the string to make a loop through each coil. At the center of each loop, pull the imaginary strings away from the center of the core .......
124: MagneQuest/Peerless Forum, Ultra Fast Diodes (0.00)
Posted by VoltSecond on 2009-02-17, 21:01:47 (68.3.231.220)
Make sure you use Ultra Fast Diodes if you aren't using a tube rectifier. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . .......
125: MagneQuest/Peerless Forum, The Crest Factor (0.00)
Posted by VoltSecond on 2009-02-17, 19:05:42 (68.3.231.220)
Usually the current rating is the RMS current. With a capacitive input supply the RMS current can be many times the output current. 3:1 is common. With a good choke input supply, the RMS current and D .......
126: Bottlehead Forum, I know a few people at work who'd like a tube guitar amp kit. (0.00)
Posted by VoltSecond on 2009-02-13, 14:37:23 (68.3.231.220)
I know a few people at work who'd like a tube guitar amp kit. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .......
127: MagneQuest/Peerless Forum, 1.5V D cell (0.00)
Posted by VoltSecond on 2009-02-10, 20:19:33 (68.3.231.220)
I think I'd try 406 turns of #27 on a 1/2 inch EI core and a 1.5V D cell. . . You could make the E and I piece out of pig iron. Keeping the airgap small gets us the closing force. With polished metal .......
128: MagneQuest/Peerless Forum, How about an E and I piece belt buckle. . . (0.00)
Posted by VoltSecond on 2009-02-09, 18:21:13 (68.3.231.220)
How about an E and I piece belt buckle with a battery to make a magnetic field that holds the belt buckle closed. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and m .......
129: Bottlehead Forum, Are you sure it wasn't that secret Bottlehead sub prototype? (nt) (0.00)
Posted by VoltSecond on 2009-01-30, 17:00:44 (68.3.231.220)
;-} Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC .......
130: Bottlehead Forum, There isn't any sonic difference between perfect and good solder joints. (0.00)
Posted by VoltSecond on 2009-01-25, 21:45:53 (68.3.231.220)
There isn't any sonic difference between perfect and good solder joints in most, if not all audio circuits. However, if the solder joint is poor to bad, the sonic difference can be huge when compared .......
131: MagneQuest/Peerless Forum, Two voltages to consider as a limit. (0.00)
Posted by VoltSecond on 2009-01-19, 19:39:09 (68.3.231.220)
Two voltages to consider as a limit. 1. If you pull the tube or the filament doesn't light, B+ will be high because it isn't loaded. This causes more voltage than usual to appear across the parafeed c .......
132: Bottlehead Forum, I found time to listen to it again. (0.00)
Posted by VoltSecond on 2009-01-07, 19:17:22 (68.3.231.220)
The electrostatic effect was 120 dB stronger than the magnetic effect. Baking the caps isn't intended to stiffen the cap, but to restrict the possible motion of the plates. Their white paper looks li .......
133: Bottlehead Forum, Vibration sensitivity (0.00)
Posted by VoltSecond on 2009-01-04, 21:00:58 (68.3.231.220)
Interesting interview, it looks like they are addressing the second term in the full partial derivative to solve microphonic issues in a capacitor: I = C dV/dt + V dC/dt. The second term is often for .......
134: MagneQuest/Peerless Forum, You can get multiturn adjustment range with a 1 turn pot. (0.00)
Posted by VoltSecond on 2008-12-28, 15:18:31 (70.162.248.88)
The adjustment doesn't use the full range of the pot with a good tube. So you set the pot up to just use the middle 1/4 to middle 1/3 of the range. Play safe and play longer! Don't be an "OUCH!" casua .......
135: MagneQuest/Peerless Forum, Try a 50 or 20 ohm pot with a resistor in each leg. (0.00)
Posted by VoltSecond on 2008-12-24, 11:03:41 (70.162.248.88)
Option 1. Try a 50 ohm pot with a 24 ohm resistor in each leg of the pot to the Tube. Pot wiper still goes to long tail resistor. Option 2. Try a 20 ohm pot with a 39 ohm resistor in each leg to the t .......
136: Bottlehead Forum, Time to make ICE wine? (0.00)
Posted by VoltSecond on 2008-12-23, 19:09:02 (70.162.248.88)
;-] Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPI .......
137: Bottlehead Forum, LED, Meter, Tube (0.00)
Posted by VoltSecond on 2008-11-29, 13:22:12 (70.162.248.88)
I am assuming this is for looks and not for serious recording use. LED version. A long time ago I made an LED VU Meter with two pairs of LM3916 (lots of LEDs on the output). I remember I needed more p .......
138: Bottlehead Forum, RE: Top plate prep work (0.00)
Posted by VoltSecond on 2008-11-24, 18:54:58 (70.162.248.88)
I first use a sponge to scrub top and bottom with orange goop (the greasy hand cleaner from an auto parts store) and a bit of cheap vinegar. I spend extra time on the holes and edges. I then rinse in .......
139: Bottlehead Forum, Two Prong Polarity (0.00)
Posted by VoltSecond on 2008-11-02, 11:10:00 (70.162.248.88)
The cable TV can cause problems. You can get a ground isolator to fix that. Before buying the ground loop isolator, unplug the cable coax and see if the problem goes away. Two prong audio equipement c .......
140: MagneQuest/Peerless Forum, RE: Wow. Not a good question when you've got a headache. (0.00)
Posted by VoltSecond on 2008-10-21, 20:51:26 (70.162.248.88)
With a Mu output, you actually need DrP more. DrP adds adjustable damping to control low frequency ringing and subsonic problems. Mu outputs are low impedance. Low impedance increases low frequency r .......
141: MagneQuest/Peerless Forum, Wow. Not a good question when you've got a headache. (0.00)
Posted by VoltSecond on 2008-10-20, 19:25:34 (70.162.248.88)
On the 26, the CCS Mu output will be low impedance. I'm not sure how low, I'd guess about 1/gm for the driver, so set Rp to 10 ohm in the spreadsheet for the 26. Play safe and play longer! Don't be an .......
142: MagneQuest/Peerless Forum, The cathode resistors are in parallel at AC (0.00)
Posted by VoltSecond on 2008-10-09, 19:09:50 (70.162.248.88)
The cathode resistors are in parallel at AC. First see if you like the direction the sound is going. If you do, you can put an inductor between ground and where the two cathode resistors tie together .......
143: MagneQuest/Peerless Forum, AC, the cap shorts the cathodes together (0.00)
Posted by VoltSecond on 2008-10-08, 21:34:09 (70.162.248.88)
AC, the cap shorts the cathodes together. So at AC it does behave like a normal long tailed pair. DC, it behaves like two seperately biased tubes. The resistor to ground insures the caps have a good h .......
144: MagneQuest/Peerless Forum, Idea'r (0.00)
Posted by VoltSecond on 2008-10-07, 19:13:52 (70.162.248.88)
An idea I've been wanting to try for a while but haven't gotten a round tuit: Lift the ground side of both cathode bypass caps. Tie them together and then route the tied pair of old ground nodes back .......
145: MagneQuest/Peerless Forum, Put in all the tubes BUT the rectifier (0.00)
Posted by VoltSecond on 2008-10-02, 18:50:23 (70.162.248.88)
Put in all the tubes BUT the rectifier. See if that works. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Rem .......
146: High Efficiency Speaker Asylum, RE: The on/off switch is probably arcing. (0.00)
Posted by VoltSecond on 2008-09-30, 20:36:14 (70.162.248.88)
The RC snubber goes across the primary of the transformer. This way you can use a bigger C than if you go across the switch. The resistor limits the current when you throw the switch. A 1 uF cap acro .......
147: MagneQuest/Peerless Forum, Unplug the amp from the wall. . . (0.00)
Posted by VoltSecond on 2008-09-30, 20:04:06 (70.162.248.88)
Does the fuse go fast (at power up or as soon as the rectifier warms up) or slow (after the music starts to play)? Slow could be an under rated fuse. Fast usually means something is broken. Fuse ratin .......
148: High Efficiency Speaker Asylum, The on/off switch is probably arcing. (0.00)
Posted by VoltSecond on 2008-09-29, 19:06:55 (70.162.248.88)
It was probably popping before, you just didn't hear it. Try a 1uF X-cap with a series flame proof 39 ohm >= 1/4W across the power transformer side of the switch. You can do it without the resistor, b .......
149: Bottlehead Forum, Inverter (0.00)
Posted by VoltSecond on 2008-09-15, 19:04:12 (70.162.248.88)
For a regulated supply a non-isolated boost can be easy to build to make 300V from 12V. One simple inductor in the power stage, one or two more for EMI filtering. Constant off-time current mode contro .......
150: Bottlehead Forum, Obsolete Military carbon comps (0.00)
Posted by VoltSecond on 2008-09-03, 19:24:34 (70.162.248.88)
Here's the story I was given when I was told I couldn't have carbon comps any more: The old Military Style carbon comps (that we can't get any more) didn't have a big problem with adsorbing moisture f .......
151: Bottlehead Forum, I haven't had problems with metal film resistors for grid stoppers. (0.00)
Posted by VoltSecond on 2008-09-02, 22:19:33 (70.162.248.88)
I haven't had problems with metal film resistors for grid, gate and base stoppers. It turns out it is more important to get the weld to the body of the resistor 1/8 to 1/4 inch from the tube socket th .......
152: Bottlehead Forum, Use it for speaker cable. (0.00)
Posted by VoltSecond on 2008-08-30, 11:26:33 (70.162.248.88)
It is high capacitance so some solid state amps won't like it, but tube amps will. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you to .......
153: MagneQuest/Peerless Forum, RE: Thanks. (0.00)
Posted by VoltSecond on 2008-08-15, 20:23:55 (70.162.248.88)
VoltSec>"output winding can be floated off of chassis to break the ground loop in the output. I don't know if you took advantage of that. " If by that you mean that secondary dot is to centre of inter .......
154: MagneQuest/Peerless Forum, Thanks. (0.00)
Posted by VoltSecond on 2008-08-14, 20:21:47 (70.162.248.88)
Thanks! It does help because we now have some place to look! ...Ears first, scope second...When both are happy, the sound is usually unbeatable. The autoformer has higher primary inductance that coul .......
155: MagneQuest/Peerless Forum, Sorry Dude. (0.00)
Posted by VoltSecond on 2008-08-08, 20:28:21 (70.162.248.88)
That came off pompous and that wasn't my goal. The way to prove if it is transformer or autoformer is to hook the transformer up as an autoformer (secondary in series with the primary) and listen. It .......
156: Bottlehead Forum, That happens. Nice Picture. (0.00)
Posted by VoltSecond on 2008-08-08, 19:12:26 (70.162.248.88)
Mistakes happen. I've embedded the lids of a bank of "oil can" electrolytic caps in the ceiling tiles at work. That stunk. (In more ways than one!) Play safe and play longer! Don't be an "OUCH!" casua .......
157: MagneQuest/Peerless Forum, RE: comparing apples to what? (0.00)
Posted by VoltSecond on 2008-08-07, 20:47:48 (70.162.248.88)
Three parts to this answer. 1. This first paragraph may seem odd, but it is the way thing work: A capacitor averages current and an inductor/ transformer integrates voltage. On a capacitor we measure .......
158: Bottlehead Forum, I haven't had a problem. (0.00)
Posted by VoltSecond on 2008-08-07, 20:18:33 (70.162.248.88)
Uninstall what you have installed. Down load a new copy. Reboot computer Re-install. If you have a problem again, write down what the error message is. Play safe and play longer! Don't be an "OUCH!" c .......
159: Bottlehead Forum, Swap components (0.00)
Posted by VoltSecond on 2008-08-05, 20:19:30 (70.162.248.88)
Try your back up amp and/or back up speakers etc. to see if the problem follows the amp, the speakers, the preamp or the music source. Remember, odd things happen. I've tracked bad sound down to a sna .......
160: General Asylum, Untried Idea (0.00)
Posted by VoltSecond on 2008-08-02, 12:37:39 (70.162.248.88)
Idea off top of my head: Caulk around the window frame to the walls of the room. Next caulk the seams around the window except for the small drain holes on the bottom. Plug moving gaps with new foam w .......
161: MagneQuest/Peerless Forum, RE: Complexity and size Soap Box (0.00)
Posted by VoltSecond on 2008-07-21, 19:36:50 (70.162.248.88)
Grossner's "Transformers for Electronic Circuits" is a good book. Midcom has a decent starter application note. Very bad grammar from previous post: It is easy to get burned by Second Order when you .......
162: MagneQuest/Peerless Forum, Complexity and size Soap Box (0.00)
Posted by VoltSecond on 2008-07-19, 09:32:02 (70.162.248.88)
Short answer: Bandwidth vs ringing is a trade off between size, cost, profit, insertion loss and other performance aspects. Lumping the ringing into two categories. (Top of the ice berg) 1. First orde .......
163: Tweakers' Asylum, MOVs (0.00)
Posted by VoltSecond on 2008-07-12, 21:14:16 (70.162.248.88)
I agree with Jon, more comments/ differrent spin: In my designs I do not place MOVs and sometimes not even Y caps from Line to chassis. They can couple transients from the line to chassis if you are n .......
164: Bottlehead Forum, RE: B+ voltage regulator in a Paramour - overkill? (0.00)
Posted by VoltSecond on 2008-07-02, 20:24:41 (70.162.248.88)
If you want to correct for line voltage variations you'll need to drop closer to 80V peak for +/- 10% line or 40V nominal. The issue with most HV regulators is they don't reject high frequencies very .......
165: Tube DIY Asylum, What is with all the cookies? (0.00)
Posted by VoltSecond on 2008-06-27, 21:22:59 (70.162.248.88)
The asylum wanted to set a dozen cookies when I logged in today. What's up? Adware or lunitic spyware? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it ( .......
166: General Asylum, RE: Next trick is to build the phono amp into the tonearm. (0.00)
Posted by VoltSecond on 2008-06-15, 23:10:32 (70.162.248.88)
That would be "better" but would limit our options. With the pre-amp at the cartridge, we could use and cartridge we wanted. This preamp would also mean we can really drive the wiring from low impedan .......
167: General Asylum, Next trick is to build the phono amp into the tonearm. (0.00)
Posted by VoltSecond on 2008-06-14, 21:31:28 (70.162.248.88)
What I'd like to see is the first gain stage at the cartridge. Shunt regulated power supplies at this point. RIAA eq, more gain, buffer and the current source to feed the preamp in the cartridge amp i .......
168: General Asylum, Recommendation for a Good Sounding PDA (0.00)
Posted by VoltSecond on 2008-06-14, 20:52:05 (70.162.248.88)
My Palm TX PDA really sounds harsh. You can hear hash with the audio stopped. Unfortunately, I'm having to listen to it at work and on business trips and life is too short for sound worse than stock M .......
169: Bottlehead Forum, RE: Transistor stacking works. (0.00)
Posted by VoltSecond on 2008-06-11, 18:54:11 (70.162.248.88)
I haven't done A-B with stacking. I haven't heard anything bad so far, but I'm careful with my layout. With 7W in an MJE, you can do the trick with the resistor across the BJT to reduce the power. Pla .......
170: Bottlehead Forum, Any Audio Stores worth visiting in St Petersburg FL (0.00)
Posted by VoltSecond on 2008-06-10, 20:43:18 (70.162.248.88)
I'll have a few hours to look around during a business trip. Any Audio Stores worth visiting in St Petersburg FL. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and m .......
171: Bottlehead Forum, You know all the cool people. . . (0.00)
Posted by VoltSecond on 2008-06-10, 19:33:14 (70.162.248.88)
I got a desk top kit for a trebuchet for our 25th anniversary. The site to get them is catapultkits. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (tw .......
172: Bottlehead Forum, Transistor stacking works. (0.00)
Posted by VoltSecond on 2008-06-10, 19:25:13 (70.162.248.88)
I've been to 2500V with FET stacking. I've done 600V with small signal transistor stacking several times. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure .......
173: Bottlehead Forum, A good son needs a good present. (0.00)
Posted by VoltSecond on 2008-06-09, 20:47:16 (70.162.248.88)
If he likes history, he may enjoy these. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying t .......
174: Bottlehead Forum, My slow internet solved (- Router was in death throws. (0.00)
Posted by VoltSecond on 2008-06-06, 18:50:52 (70.162.248.88)
My very old Linksys router died. I purchased a new one and all is good again. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch i .......
175: MagneQuest/Peerless Forum, Email Address (0.00)
Posted by VoltSecond on 2008-06-03, 21:57:31 (72.222.236.36)
Mike, I'd put your email address in a .gif format to make it a little harder for those annoying people who send very annoying emails about annoying non-audio products. Play safe and play longer! Don't .......
176: Bottlehead Forum, RE: Second Post, OT PC Trouble, Yes! Again! (0.00)
Posted by VoltSecond on 2008-06-01, 16:49:35 (72.222.236.36)
1. Open a Command Prompt (Type "command" in the "run" window.) Type in CHKDSK C: /R "Y" to run on reboot. If you have a D: drive also type in CHKDSK D: /R "Y" to run on reboot. Reboot the computer and .......
177: Bottlehead Forum, RE: c4s (0.00)
Posted by VoltSecond on 2008-05-31, 21:51:31 (72.222.236.36)
C4S reduces power supply coupled noise, it can reduce distortion because the plate load is now higher and it increases the gain a small amount. I made my own CCS for the seduction and the output was q .......
178: Bottlehead Forum, I saw it about 15 seconds before Jeffrey did. (0.00)
Posted by VoltSecond on 2008-05-31, 10:53:22 (72.222.236.36)
It didn't look like Nipper was in pain to me. . . Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Mo .......
179: Bottlehead Forum, Little Nipper's "Dogs Gone Wild" pictures at VSAC (0.00)
Posted by VoltSecond on 2008-05-30, 16:31:38 (72.222.236.36)
Little Nipper's "Dogs Gone Wild" pictures at VSAC in the Experience Music room. Moderation. . .never! Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure i .......
180: General Asylum, Orange Headphone Amp at VSAC 2008 (0.00)
Posted by VoltSecond on 2008-05-27, 21:24:58 (72.222.236.36)
I listened to all but the orange headphone amp at VSAC 2008. I was told it was one of the best there. Can someone send me a link to the schematic? Play safe and play longer! Don't be an "OUCH!" casua .......
181: MagneQuest/Peerless Forum, First Bad Shock (0.00)
Posted by VoltSecond on 2008-05-27, 17:05:37 (72.222.236.36)
First Bad shock was through my arm. I was frozen in place, brain working, rest of body not. Not fun. Root cause: Missing bleeder resistor on a cap. Many years later got shocked and flew back off the h .......
182: Bottlehead Forum, It was a lot of fun; however, Little Skipper over did it a bit. (nt) (0.00)
Posted by VoltSecond on 2008-05-27, 08:47:15 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
183: Bottlehead Forum, Where's the sign up sheet? I've got my $25 ready. (0.00)
Posted by VoltSecond on 2008-05-18, 19:56:14 (72.222.236.36)
Does Paypal work? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warra .......
184: Bottlehead Forum, How big is the circuit breaker in the show room? (0.00)
Posted by VoltSecond on 2008-05-18, 19:26:37 (72.222.236.36)
Just curious. . . Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warra .......
185: MagneQuest/Peerless Forum, RE: Can it be a good thing? (0.00)
Posted by VoltSecond on 2008-05-06, 22:49:07 (72.222.236.36)
Turn on transients are likely to undo any possible benefits. It wouldn't be that effective anyway. Also, I wouldn't want a powered bulk eraser within inches of my tubes to degauss my iron after I turn .......
186: MagneQuest/Peerless Forum, Doesn't have to be ferrous to be affected by an AC field. (0.00)
Posted by VoltSecond on 2008-05-06, 22:32:26 (72.222.236.36)
An ac magnetic field in a shorted loop of metal will cause current to flow in the metal and thus heat and/or mechanical force in the metal. I've tried holding a CD next to a bulk tape eraser (not a ta .......
187: MagneQuest/Peerless Forum, It is unlikely to do anything. (0.00)
Posted by VoltSecond on 2008-05-05, 20:25:21 (72.222.236.36)
Short of pounding it with the degausser, you'd really have to try really hard to do anything. More than a few inches away, nothing at all happens with a hand held degausser. Play safe and play longer! .......
188: Bottlehead Forum, RE: The Buff (0.00)
Posted by VoltSecond on 2008-05-03, 20:22:59 (72.222.236.36)
CCS for the design is here. http://www.siteswithstyle.com/VoltSecond/Chaperone_IS_design/chap_is_design.html Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and meas .......
189: MagneQuest/Peerless Forum, Leaving Dr.P in won't hurt when driving a resistor. (0.00)
Posted by VoltSecond on 2008-04-29, 19:53:25 (72.222.236.36)
The turn-on thump will just last longer. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying t .......
190: MagneQuest/Peerless Forum, RE: A little droop on the low end can be good (0.00)
Posted by VoltSecond on 2008-04-28, 20:23:32 (72.222.236.36)
With a 100K resistive load you won't need DrP, just use the .22uF cap. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .......
191: MagneQuest/Peerless Forum, A little droop on the low end can be good (0.00)
Posted by VoltSecond on 2008-04-27, 11:57:59 (72.222.236.36)
Too sharp of a drop off in the frequency response tends to indicate low frequency ringing. A little peaking ( With 0.22uF parafeed, try 4.7u and 5.6k or 2.0u and 8.6K for Dr.P to drop the peak volt/fr .......
192: Bottlehead Forum, RE: What do you think of this delay start up "thing"? (0.00)
Posted by VoltSecond on 2008-04-25, 22:14:09 (72.222.236.36)
I remember working on a way to make this do 2000V, I can't find my notes. Of course I like mine better because it is mine. Mine also resets the delay quickly if you want to swap tubes in and out. Pla .......
193: Bottlehead Forum, Portable version exists if you can bench 100 lbs. (0.00)
Posted by VoltSecond on 2008-04-21, 20:40:47 (72.222.236.36)
The Motor Gen Set had a few advantages for correcting severe drop outs and offers frequency regulation, but the CVT will be less expensive. Both are noisy. Sola has a bench top model too. I saw one in .......
194: Bottlehead Forum, They used to make ~1.5kVA motor generator sets. (0.00)
Posted by VoltSecond on 2008-04-20, 20:26:37 (72.222.236.36)
The motor spins a flywheel to run a generator. These offer very high line isolation plus galvanic isolation too. The one I didn't get, but was drooling over 10 years ago, was used for running low nois .......
195: Bottlehead Forum, Questions (0.00)
Posted by VoltSecond on 2008-04-17, 20:40:31 (72.222.236.36)
What is the Hilton online booking code to get the discount? When is the Monday breakfast expected to end so we can plan the flight back home? Play safe and play longer! Don't be an "OUCH!" casualty. U .......
196: MagneQuest/Peerless Forum, RE: Mike, do you make any B7 1:1 ct? (0.00)
Posted by VoltSecond on 2008-04-16, 20:42:42 (72.222.236.36)
Unless it is two tube outputs that you could directly short together, I wouldn't recommend summing L+R through a transformer. You'd want a series resistor between each input and the summation point. I .......
197: Bottlehead Forum, Linear / non-linear (0.00)
Posted by VoltSecond on 2008-04-12, 13:47:57 (72.222.236.36)
Assuming the heater's resistance is linear (it isn't) ....Power = 1500W * (208V/220V)^2 = 1341 watts. W = V^2/R or the heater's R = V^2/W R = 220^2/1500W = 32.27 ohm ....W = 208V^2/32.27ohm = 134 .......
198: MagneQuest/Peerless Forum, RE: Autoformer Question (0.00)
Posted by VoltSecond on 2008-04-03, 20:58:33 (72.222.236.36)
Overview of method: Tag the leads on the autoformer and tag the leads going to the speaker wires Remove the autoformer from the speaker. Apply ~5.00V at 1 kHz from input to "ground" Record the input .......
199: SET Asylum, Tube amps don't double output power with halving the ohms. (0.00)
Posted by VoltSecond on 2008-04-01, 19:47:45 (72.222.236.36)
"My four watt amp should give me 8 watts at four ohms, 16 watts at two ohms, and 32 watts at one ohm." It doesn't quite work that way. SETs are both voltage and current limited on the output. My new c .......
200: Bottlehead Forum, RE: C4S in differential output stage (0.00)
Posted by VoltSecond on 2008-03-28, 22:29:51 (72.222.236.36)
Buy Doc's C4S if it will do the job. You could use a TO-247 FET on a heatsink in the topology I used in the S5 amp http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=497-5415-5-ND I'd li .......
201: Bottlehead Forum, RE: finding an affordable 1000volt probe is a problem... (0.00)
Posted by VoltSecond on 2008-03-06, 05:32:50 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
202: Bottlehead Forum, Scope Probes (0.00)
Posted by VoltSecond on 2008-03-04, 18:41:11 (72.222.236.36)
Some 10:1 scope probes are rated for as little as 300V peak, others as high as 600Vpk. I have a 100:1 scope probe that is rated for 1200V peak. I have a friend with a 1000:1 scope probe rated for 20,0 .......
203: High Efficiency Speaker Asylum, Has anyone used the peak of a vaulted ceiling to launch a bass horn into a room? (0.00)
Posted by VoltSecond on 2008-03-02, 17:02:34 (72.222.236.36)
Has anyone used the peak of a vaulted ceiling to launch a bass horn into a room? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touc .......
204: Tube DIY Asylum, RE: Curious: Does the choice of SS diode matter in a hybrid rectifier ... (0.00)
Posted by VoltSecond on 2008-02-28, 14:56:34 (72.222.236.36)
Buy the ultrafast version of the SS diode. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying .......
205: SET Asylum, "hogging" and doing all the work (0.00)
Posted by VoltSecond on 2008-02-28, 14:47:22 (72.222.236.36)
"hogging" and doing all the work is mostly occurs because both the plate and cathode are in parallel at dc. If either are seperate at dc, they'll share nicely. If both are common at dc (with no servo .......
206: Bottlehead Forum, Encapsulate it in thermally conductive epoxy . . . (0.00)
Posted by VoltSecond on 2008-02-26, 19:15:28 (72.222.236.36)
Encapsulating it in thermally conductive epoxy may work. Too thick of an epoxy can be an insulator. RTV is always an insulator. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, dis .......
207: Tube DIY Asylum, Open the CT. . . (0.00)
Posted by VoltSecond on 2008-02-24, 14:19:51 (72.222.236.36)
". . .I abandoned Asylum registration during some flap. . .", Yeah, I let my self get baited a few years ago and actually got fed up enough I took my website down for a bit more than a week. An email .......
208: High Efficiency Speaker Asylum, I haven't heard one system ... (0.00)
Posted by VoltSecond on 2008-02-24, 13:42:16 (72.222.236.36)
I haven't heard one system that does everything right on every piece of music. Find a place to store a couple of different amps and a couple of different sets of speakers so you can swap things in and .......
209: Tube DIY Asylum, Henry, send me Asylum Mail. (0.00)
Posted by VoltSecond on 2008-02-23, 15:13:13 (72.222.236.36)
Henry, send me Asylum Mail. I'm missing something. Won't be the first time. Won't be the last. I'd like to understand how it is series without bystanders turning this from a friendly discussion in to .......
210: Tube DIY Asylum, RE: CCS on cathode questions (0.00)
Posted by VoltSecond on 2008-02-22, 18:04:47 (72.222.236.36)
>>>First, I understand how a css in the tail of two triodes (or pentodes) forces differential, by not allowing the AC in the cathodes easy access to a ground (and puts the tubes in "series" as I've he .......
211: MagneQuest/Peerless Forum, Using more than one is a problem (0.00)
Posted by VoltSecond on 2008-02-21, 19:32:18 (72.222.236.36)
Parallel doesn't help the voltage problem and doubles the parasitic capacitance. Series has the problem that choke going to the plate has to handle ~2000V peak to peak on the winding to core voltage w .......
212: MagneQuest/Peerless Forum, Design issue for manufacture. (0.00)
Posted by VoltSecond on 2008-02-21, 19:23:34 (72.222.236.36)
With a 1000V B+, first order you get 2000V peaks. You'll need to find something that follows the larger of the IPC external layer spacing rules in a moderately contaminated environment (i.e. dust and .......
213: Bottlehead Forum, and play the 1812 right when the guy T's off. (0.00)
Posted by VoltSecond on 2008-02-17, 10:08:23 (72.222.236.36)
The guy in the back ground looks like he is golfing. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: .......
214: Bottlehead Forum, Are you sure it wasn't just an excuse (0.00)
Posted by VoltSecond on 2008-02-08, 19:11:02 (72.222.236.36)
Are you sure it wasn't just an excuse to bean you with a potato? ;-] Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .O .......
215: Tube DIY Asylum, If this is a switcher. . . (0.00)
Posted by VoltSecond on 2008-02-01, 19:41:38 (72.222.236.36)
Many switchers whistle and make noise a light loads. The energy star ones are worse at making noise than the old style ones. However, I like the protection features in the new switchers better than th .......
216: Tube DIY Asylum, MRS25 Phoenix Passives (0.00)
Posted by VoltSecond on 2008-01-30, 19:20:26 (72.222.236.36)
I used the MRS25 (from Phoenix Passives available at Digikey) in the gain stage of a recent design of mine and I liked them. I ran them at about 1/3 rated power at the peaks of the audio signal. Stead .......
217: Tube DIY Asylum, PSUD (0.00)
Posted by VoltSecond on 2008-01-24, 18:47:33 (72.222.236.36)
I've seen the ringing on the cathodes of the diodes in real life. What parasitics did you put in the Orcad run? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and mea .......
218: Tube DIY Asylum, Unique volume knob idea (0.00)
Posted by VoltSecond on 2008-01-23, 19:58:53 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
219: MagneQuest/Peerless Forum, I'm putting MilliVolt to bed. (0.00)
Posted by VoltSecond on 2008-01-21, 21:45:54 (72.222.236.36)
I'm putting MilliVolt to bed. In MilliVolt's view of the world, dad is supposed to sit in a chair and read a book until MilliVolt falls asleep. I've never tried to repair a rusty transformer. My thoug .......
220: SET Asylum, I was told once the vacuum is broken, the getter is toast. (0.00)
Posted by VoltSecond on 2008-01-20, 10:20:11 (72.222.236.36)
The getter will be gone once the vacuum is broken, so that will have to also be renewed. . . .I'm envisioning tiny robots working in a vacuum chamber. . . Best of luck. Play safe and play longer! Don' .......
221: Tube DIY Asylum, I agree (0.00)
Posted by VoltSecond on 2008-01-20, 09:54:37 (72.222.236.36)
In reality, 6W isn't noticably louder than 2W if you're not clipping either amp. ~10X the wattage sounds twice as loud on the same piece of music. So don't discount 2A3 amps. Play safe and play longe .......
222: Tube DIY Asylum, I've got the MK III board (0.00)
Posted by VoltSecond on 2008-01-17, 19:34:32 (72.222.236.36)
I put the MK III board in my dynacos and I remembered that I liked it. No pictures at this time. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice .......
223: MagneQuest/Peerless Forum, Altec (0.00)
Posted by VoltSecond on 2008-01-12, 10:58:14 (72.222.236.36)
I used to have a small wood cone computer speaker (Altec?) That was quite good for a small speaker being fed by a sound card. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discha .......
224: MagneQuest/Peerless Forum, RE: miscellaneous ramblings, ruminations, and intuitions (0.00)
Posted by VoltSecond on 2008-01-10, 19:53:05 (72.222.236.36)
Hook ground of T1 to cathode of V1. It removes a lot of the sound of the cathode cap. Is L1 actually a tranny to break the ground loop? Is T2 a 10K primary? Play safe and play longer! Don't be an "OUC .......
225: Tube DIY Asylum, RE: What are possible cause for rectifier tube buzz/Hum? (0.00)
Posted by VoltSecond on 2008-01-10, 19:19:44 (72.222.236.36)
My Audio Note Kit 4 (push pull) benefited from an 1A 1000v ultrafast diode in series with the B+ diode bridge and two 3A schottky diodes paralleled across the filament diode bridge. (A total of 3 adde .......
226: Tube DIY Asylum, LC Tank Q (0.00)
Posted by VoltSecond on 2008-01-10, 19:08:23 (72.222.236.36)
. One web page of the couple I have on this subject. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: .......
227: Tube DIY Asylum, RE: PP using only 6sn7 - circuit suggestion (0.00)
Posted by VoltSecond on 2008-01-05, 17:58:39 (72.222.236.36)
You can use the parafeed calculator to figure out how much output power you'll get. In class A push pull, the output power is the same as two single ended class A tubes operating in parallel. My gues .......
228: High Efficiency Speaker Asylum, Hornshoppe Horns (0.00)
Posted by VoltSecond on 2007-12-29, 21:40:36 (72.222.236.36)
Hornshoppe Horns, less than 2m away, but more than 2m apart. In my office driven with a 1W amp. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) .......
229: Bottlehead Forum, A speaker manufacture said (0.00)
Posted by VoltSecond on 2007-12-23, 17:28:12 (72.222.236.36)
During an audiophile meeting years ago, a speaker manufacture said to get the sound of the bypass cap, the bypass has to be about 1/3 the total cap. For 69uF he'd use a 47uF moderate cost cap and a 22 .......
230: Bottlehead Forum, A longer winded version of Dr P. (0.00)
Posted by VoltSecond on 2007-12-23, 17:12:50 (72.222.236.36)
The Dr. P Excel spreadsheet is at the bottom of the page. Oh. Dublin Dr. Pepper is better than normal too. http://www.dublindrpepper.com/ Play safe and play longer! Don't be an "OUCH!" casualty. Un .......
231: MagneQuest/Peerless Forum, PP CCS drive wish list. (0.00)
Posted by VoltSecond on 2007-12-21, 08:53:17 (72.222.236.36)
I'm hoping to have time next week to play with my tube amps. I am wanting to finally get around to making a ->good The plan will be to have one pot on it for a one time adjust for the balance. This ad .......
232: Tube DIY Asylum, Silicon gives up pretty fast (0.00)
Posted by VoltSecond on 2007-12-16, 14:54:02 (72.222.236.36)
Silicon gives up pretty fast with power and voltage stress. 260V * 3 mA = .78W. This stress level will be seen with arcs, start up, caps shorting, mistakes soldering etc. I normally don't run this siz .......
233: High Efficiency Speaker Asylum, Use Cat 5 cable (0.00)
Posted by VoltSecond on 2007-12-09, 19:21:36 (72.222.236.36)
I'd probably start with 40 or 50 feet to end up with 30 braided. I'm not sure I would strip the outer jacket off either; however, it does look nicer with out the outer jacket. SETs can handle the capa .......
234: Tube DIY Asylum, Yep, 2400 ohms -) 3.3 uF (0.00)
Posted by VoltSecond on 2007-12-02, 18:36:03 (72.222.236.36)
I happen to like polyprop and foil. You can find some nice AEON 1uF 630V polyprop and foils used for speaker crossovers, three of those in parallel and you're good to go. I got mine at a local car aud .......
235: Bottlehead Forum, RE: EMI/RF screen (0.00)
Posted by VoltSecond on 2007-12-02, 18:29:24 (72.222.236.36)
Try a couple layers spaced two to five hole diameters apart (>1/2 spacing for 1/4 inch screen, >1/4 inch spacing for 1/8 screen.) I forget the actual formula for optimum spacing, but the stuff is chea .......
236: Tube DIY Asylum, RE: What happens if a parafeed cap is too big? (0.00)
Posted by VoltSecond on 2007-12-02, 10:43:37 (72.222.236.36)
Too big of a parafeed cap is difficult to do with a choke to B+. Usually other things (like cost and size) limit the size first. With a CCS to B+, too big of a cap COULD lead to subsonics robbing ava .......
237: Bottlehead Forum, RE: EMI/RF screen (0.00)
Posted by VoltSecond on 2007-12-01, 11:57:08 (72.222.236.36)
Start with perforated metal on the bottom. Make sure if something accidentally hits the bottom hard, the dent in the metal doesn't hit any exposed metal like the 115V or B+. This metal should be conne .......
238: Tube DIY Asylum, power rating, voltage rating and surge rating (0.00)
Posted by VoltSecond on 2007-11-28, 18:55:52 (72.222.236.36)
Resistors have a power rating, voltage rating and transient power rating. The power rating is straight forward as point out in the other email. Rated power = V^2 / R or I^2 * R. I've run resistor at .......
239: Bottlehead Forum, For a HV supply with solid state rectifiers. . . (0.00)
Posted by VoltSecond on 2007-11-27, 19:25:39 (72.222.236.36)
For a HV supply with solid state rectifiers, modify a similar diode to have those parameters and that should be good enough. A 1V difference in the diode is much much much smaller than changes in the .......
240: MagneQuest/Peerless Forum, XL for me (0.00)
Posted by VoltSecond on 2007-11-14, 17:51:46 (72.222.236.36)
Have you seen the wimpy load limits on office chairs? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember .......
241: Tube DIY Asylum, Add a zero behind C1 (0.00)
Posted by VoltSecond on 2007-11-07, 18:08:18 (72.222.236.36)
With C1 as shown or 10X bigger, I doubt a short transient will change the bias point significantly. If you used two tubes, the tubes don't match exactly so the circuit will work with a small imbalance .......
242: Tube DIY Asylum, Great minds . . . (0.00)
Posted by VoltSecond on 2007-11-06, 20:23:52 (72.222.236.36)
I've seen that circuit somewhere before. . . Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifyi .......
243: Tube DIY Asylum, RE: Tube/transistor push-pull output stage (bizarre) (0.00)
Posted by VoltSecond on 2007-11-06, 20:08:47 (72.222.236.36)
You could re-arrange the bias to look like the above. The transformer attaches to the drain of the FET. The tube bias resistor attaches at the point marked "in" At DC it works as a precision non-inver .......
244: Bottlehead Forum, RE: babyWav (0.00)
Posted by VoltSecond on 2007-10-29, 19:41:13 (72.222.236.36)
Baby sign language was probably the best thing we did with MilliVolt. She could sign “more”, want, milk, eat, drink etc. months before she could talk. Imagine wanting a Dr.Pepper and not being able to .......
245: Tube DIY Asylum, ON semi used to make good ones. (0.00)
Posted by VoltSecond on 2007-10-23, 21:48:30 (72.222.236.36)
ON semi used to make good ones. I haven't tried them recently. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .......
246: Tube DIY Asylum, The old microsim 9.1 student edition (0.00)
Posted by VoltSecond on 2007-10-20, 10:38:23 (72.222.236.36)
The old microsim 9.1 student edition (Free) was the easy to use so far, but was limited. The trick was to use the Psched editor, not the Orcad editor. Do a web search for 91pspstu.exe (27.95 megbytes) .......
247: Tube DIY Asylum, RE: thanks (0.00)
Posted by VoltSecond on 2007-10-11, 19:33:08 (72.222.236.36)
j is the imaginary number that makes j 2 pi F L an imaginary impedance. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .......
248: Tube DIY Asylum, I'll try (0.00)
Posted by VoltSecond on 2007-10-10, 20:11:26 (72.222.236.36)
I've been having more problems than usual with simple explanations lately. I don't know what has happened, but I'll try to be simple. Resistors have a "real impedance". Ideal capacitors and inductors .......
249: Tube DIY Asylum, Chokes add like resistors. (0.00)
Posted by VoltSecond on 2007-10-09, 19:19:12 (72.222.236.36)
Resistor I = V/R At a given frequency choke I = V/(2*PI*F*L) Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .R .......
250: Tube DIY Asylum, Gain (0.00)
Posted by VoltSecond on 2007-10-03, 20:31:01 (72.222.236.36)
Add a 10K resistor in series with the top 47k and move the 24uF from where it is to the 10K-47K junction. That should give a bit more gain (~2 dB). Play safe and play longer! Don't be an "OUCH!" casu .......
251: Tube DIY Asylum, High Z one end and Low Z the other end often is better. (0.00)
Posted by VoltSecond on 2007-09-30, 18:11:47 (72.222.236.36)
High Z one end and Low Z the other end often is better. To get filtering, you feed a high Z into a low Z (or visa versa). High Z to High Z and low Z to low Z doesn't buy much in the terms of filtering .......
252: Tube DIY Asylum, Both ways valid. High Z one end Low Z other end is what is critical (0.00)
Posted by VoltSecond on 2007-09-30, 17:59:37 (72.222.236.36)
Both ways are valid. High Z one end Low Z other end is what is critical. I often like a little resistance (or a ferrite bead) in series on the low Z end to limit RF drive in and out of the cable shiel .......
253: MagneQuest/Peerless Forum, Impedance Match is needed at low frequencies too. (0.00)
Posted by VoltSecond on 2007-09-30, 17:24:04 (72.222.236.36)
5000 ohm to 8 ohms gives a 25:1 turns ratio. That's not practical for multifilar RF techniques because of primary side capacitance and voltage stress issues. The resonances with split windings can be .......
254: Bottlehead Forum, Allegro non Troppo, 1977 (0.00)
Posted by VoltSecond on 2007-09-29, 21:36:10 (72.222.236.36)
Allegro non Troppo: The animation is not up to modern standards, the satire is. The beginning makes more sense the second time you watch it. Play safe and play longer! Don't be an "OUCH!" casualty. Un .......
255: Tube DIY Asylum, Mu Metal is fussy (0.00)
Posted by VoltSecond on 2007-09-29, 21:12:57 (72.222.236.36)
Mu Metal works better than standard magnetic iron until you bend it. Once it is bent, standard iron is better until you re-anneal the mu-metal. You can bend iron and it doesn't significantly degrade. .......
256: Bottlehead Forum, RE: Seduction blows fuses - Revisited (0.00)
Posted by VoltSecond on 2007-09-19, 19:48:46 (72.222.236.36)
Other tricks Pull all the tubes. Attach a 9V battery to the regulated filament to make sure there aren't any new shorts. Pull all the tubes, Attach three 9V batteries to B+ at the output of the rectif .......
257: Bottlehead Forum, Glad to hear that you missed a nasty Ouch! (nt) (0.00)
Posted by VoltSecond on 2007-09-17, 20:44:02 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
258: Tube DIY Asylum, I'd increase the ohm of the resistors between the filter caps. (0.00)
Posted by VoltSecond on 2007-09-11, 20:56:11 (72.222.236.36)
In a pre-amp I'd increase the ohms of the resistors between the first and second filter caps. This will drop the voltage and provide more B+ ripple attenuation. Lowering the value of the first cap aft .......
259: High Efficiency Speaker Asylum, Nice legs. What's the rest look like? (nt) (0.00)
Posted by VoltSecond on 2007-09-11, 20:05:18 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
260: High Efficiency Speaker Asylum, I've run my hornshoppe horns with the T-amp (0.00)
Posted by VoltSecond on 2007-09-09, 13:54:57 (72.222.236.36)
They worked well with it. The T-amp really needs a regulated 12V to work its best. I used an LM317 powered by a wall wart. I have a friend powering a Klipsch horn (La Scala if memory serves me right) .......
261: Tube DIY Asylum, Ditto, use the UF1007 other ultrafast diode. (0.00)
Posted by VoltSecond on 2007-09-01, 10:49:35 (72.222.236.36)
Many vendors call their 1000V ultrafast xx4007 a xx1007. The "1" is for 1 amp in this case. The 1n4007 is a 1 amp part, the number just happens to start with a "4". Changing from a 1n4007 to a UF1007 .......
262: Tube DIY Asylum, Check for a leaky coupling cap. (0.00)
Posted by VoltSecond on 2007-08-31, 06:30:36 (72.222.236.36)
They pull the grid high and cause the tube to overheat. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Rememb .......
263: Tube DIY Asylum, -103 dBW re 8 ohms (0.00)
Posted by VoltSecond on 2007-08-30, 19:01:00 (72.222.236.36)
Good job. You don't get levels like that without more than just "moderate care" in the layout and parts placement. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and .......
264: Tube DIY Asylum, Input chokes will ring (0.00)
Posted by VoltSecond on 2007-08-26, 21:44:06 (72.222.236.36)
Two major causes of ringing on the diode side of the choke: 1. The choke doesn't have enough inductance. i.e. it is operating below critical inductance. When the output choke runs dry (hits zero curre .......
265: MagneQuest/Peerless Forum, I like my 2A3 parafeed running with a 5K plate. (0.00)
Posted by VoltSecond on 2007-08-26, 11:38:40 (72.222.236.36)
P.J.'s numbers are probably better than mine, but I'm bored and going to comment anyway. (I'm on the third repeat of Blue's Clues with MilliVolt today.) My spreadsheet with Ib0=5 mA and 12W plate spit .......
266: Tube DIY Asylum, Fun and games. (0.00)
Posted by VoltSecond on 2007-08-21, 19:18:48 (72.222.236.36)
51 C delta * 9 / 5 = 92 F delta 0C ambient = 32F Ambient 51C ambient = 124F ambient 124F ambeint - 32F ambient = 92F Rise -40 is darn cold using either scale. I've seen 124F in the shade (under a tre .......
267: Tube DIY Asylum, Sounds Normal (0.00)
Posted by VoltSecond on 2007-08-20, 19:58:11 (72.222.236.36)
Pure Copper changes .393% / C A 10 C (18F) change is a 4% change in resistance. 5 ohms to 6 ohms (20%) is a 51C change or 92F. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, disch .......
268: MagneQuest/Peerless Forum, Angel Hair (0.00)
Posted by VoltSecond on 2007-08-20, 19:22:12 (72.222.236.36)
First day on the job out of college, they sent me to strip some angel hair magnet wire in a solder pot. It was a good joke. By the time the enamel burns off, the wire is gone. I pulled the same joke o .......
269: Tube DIY Asylum, I didn't see the plots (0.00)
Posted by VoltSecond on 2007-08-19, 15:58:26 (72.222.236.36)
Often if you bias the filaments >10V higher than the cathode, the hum problems lessen. 12AU7 is good for 180V fil to cath. 0.80 times this is 144V. I've found R1 in the power supply often works better .......
270: MagneQuest/Peerless Forum, Add Sowter (0.00)
Posted by VoltSecond on 2007-08-19, 10:25:39 (72.222.236.36)
They have some offerings that are unique and worthwhile. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Reme .......
271: MagneQuest/Peerless Forum, I heard a TL-404 used as a volume control. (0.00)
Posted by VoltSecond on 2007-08-16, 16:23:57 (72.222.236.36)
I heard a TL-404 used as a volume control and liked it. I've seen the benefits of transformer isolation. I just want both at the same time. I also want to be mega-rich, in perfect health and get to ea .......
272: MagneQuest/Peerless Forum, Caution: Autoformer TVCs do not offer ground isolation. (0.00)
Posted by VoltSecond on 2007-08-15, 20:40:10 (72.222.236.36)
Caution: Autoformer TVCs do not offer ground isolation, but they do offer other benefits over a resistive divider volume control. What would be cool if Mike turned this part into a ground isolating TV .......
273: Tube DIY Asylum, RE: OPT / gap question (0.00)
Posted by VoltSecond on 2007-08-08, 19:58:56 (72.222.236.36)
With the same turns, going from series feed to parafeed on the inductor doubles the allowable voltage swing or 4X the power. Restacking iron (especially after it is varnished) is difficult at best. P .......
274: MagneQuest/Peerless Forum, RE: Humming Hammond (0.00)
Posted by VoltSecond on 2007-08-05, 14:43:50 (72.222.236.36)
Here's another idea. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their wa .......
275: SET Asylum, Parafeed will need good parts too. (nt) (0.00)
Posted by VoltSecond on 2007-08-01, 19:50:08 (72.222.236.36)
/ Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
276: Tube DIY Asylum, Alternate option (0.00)
Posted by VoltSecond on 2007-07-13, 00:05:33 (72.222.236.36)
Make a bridge out of four UF4007 diodes and put one Cree diode between the +side of the bridge and the first capacitor. The capacitance and leakage current of the Cree (80pF 0V 20uA) allow the will UF .......
277: Tube DIY Asylum, RE: RRSF Question (0.00)
Posted by VoltSecond on 2007-07-10, 20:31:03 (72.222.236.36)
I'd tune the snubber with the original diodes and then change to ultrafast diodes. I've found that the 50/60 Hz transformer has a bigger effect on the correct snubber values than the diode. Owning a s .......
278: MagneQuest/Peerless Forum, Mike, if you aren't bidding on that Advent, let us know. (0.00)
Posted by VoltSecond on 2007-07-06, 20:44:09 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
279: Tube DIY Asylum, Noise (0.00)
Posted by VoltSecond on 2007-07-06, 20:17:17 (72.222.236.36)
A moderate length answer to a question that has filled books. Noise that causes “BUZZ” from the speakers can actually be audio frequency noise that is getting in the system. For now I'm going to call .......
280: Tube DIY Asylum, Assuming this is a series regulator, (0.00)
Posted by VoltSecond on 2007-07-04, 20:14:08 (72.222.236.36)
Assuming this is a series regulator, put a 1.5KE250A across the MJE to get through start up. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) bef .......
281: Tube DIY Asylum, Without reading the article, Parallel doesn't make sense to me (0.00)
Posted by VoltSecond on 2007-06-29, 18:58:16 (72.222.236.36)
Without reading the article, Parallel doesn't make sense to me. In series with the choke makes some sense if you are attempting to reduce turn-off thumps. Play safe and play longer! Don't be an "OUCH .......
282: SET Asylum, About 4V peak (0.00)
Posted by VoltSecond on 2007-06-29, 18:55:45 (72.222.236.36)
Listening with my HornShoppe horns in my office(about 93 dB/w), I seldom need more than 4V peak (equivalent to 1W rms) I'm fairly happy and any louder and Mrs Volt tells me to turn it down. Going to 9 .......
283: Tube DIY Asylum, I second that idea (0.00)
Posted by VoltSecond on 2007-06-26, 19:08:25 (72.222.236.36)
However, I'd use a UF4007 just to gild the lily. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Mod .......
284: Tube DIY Asylum, I'll play too. (0.00)
Posted by VoltSecond on 2007-06-25, 20:26:28 (72.222.236.36)
I've never thought about continuous clipping with tubes at high B+ before, so I'll think out loud and see what happens. Thought path 1: I'd put a UF4007 (not a 1n4007) instead of a 50V zener between t .......
285: Tube DIY Asylum, Did you transformer couple the input or output? (0.00)
Posted by VoltSecond on 2007-06-24, 13:05:59 (72.222.236.36)
Did you transformer couple the input or output? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modi .......
286: Tube DIY Asylum, RE: Finally 27 PS success.......dang what a test of patience. (0.00)
Posted by VoltSecond on 2007-06-23, 16:21:45 (72.222.236.36)
Looks great! How did you couple the input and output to the tube? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. .......
287: Tube DIY Asylum, Please use more than the 10 ohm resistor. (0.00)
Posted by VoltSecond on 2007-06-23, 12:59:18 (72.222.236.36)
First topic: Make sure you debur the holes and chassis. Second topic: Please use more than the 10 ohm resistor. Nasty failures happen. The goal is to keep all metal at safe voltage levels worst case f .......
288: Tube DIY Asylum, Output tranny or line transformer? (0.00)
Posted by VoltSecond on 2007-06-23, 11:29:19 (72.222.236.36)
For the output transformer, rated power has little to do with performance. A well designed 10W transformer will walk all over a generic 50W transformer at 18W output. Unfortunately, new, good output t .......
289: Tube DIY Asylum, RE: Use a TO-247, not TO-220 (0.00)
Posted by VoltSecond on 2007-06-22, 20:25:08 (72.222.236.36)
What ever piece of metal it gets screwed to, make sure that metal has a current path back to the ground side of the power transformer so that if the insulator fails, the fuse pops and heatsink doesn't .......
290: Tube DIY Asylum, RE: Higher current ccs? (0.00)
Posted by VoltSecond on 2007-06-22, 20:22:45 (72.222.236.36)
3.8W at 100 mA means 38V drop across the CCS. I have something easy that you can modify to work. For 100 mA, start with 100 ohms for R1 and use a larger heatsink and trim it in. Play safe and play lon .......
291: Tube DIY Asylum, Use a TO-247, not TO-220 (0.00)
Posted by VoltSecond on 2007-06-21, 19:07:09 (72.222.236.36)
A TO-220 arcs below 1 kV to the mounting screw even with an insulating bushing. I've had TO-247 with a Berquist K10 insulator runing above 1000V. Play safe and play longer! Don't be an "OUCH!" casualt .......
292: MagneQuest/Peerless Forum, Mr KiloVolt (0.00)
Posted by VoltSecond on 2007-06-20, 20:51:24 (72.222.236.36)
What a lucky guy not to have an HOA. Click on the link below. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .......
293: Bottlehead Forum, 400V is a bit high (0.00)
Posted by VoltSecond on 2007-06-19, 21:56:44 (72.222.236.36)
The C4S is only rated for 300V. Since it is solid state, this is the voltage where it breaks, not the normal operating voltage like a tube specifies. To add a C4S you'll need to drop B+ to the C4S dow .......
294: MagneQuest/Peerless Forum, Wind a sample coil and test it (0.00)
Posted by VoltSecond on 2007-06-16, 08:54:50 (72.222.236.36)
You'll want to test saturation flux, residual flux, perm vs excitation, core loss vs drive and core loss vs frequency. Measure the lamination thickness to make the process quicker. Play safe and play .......
295: Tube DIY Asylum, RE: high DCR secondary (power transformer) (0.00)
Posted by VoltSecond on 2007-06-14, 21:26:18 (72.222.236.36)
I have several pages on this topic posted. http://www.siteswithstyle.com/VoltSecond/tube_psu_notes/TUBE_PSU_NOTES.html Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it .......
296: Bottlehead Forum, A few advantages to registering (0.00)
Posted by VoltSecond on 2007-06-12, 22:25:22 (72.222.236.36)
A few advantages to registering 1. It partially locks your screen name. People will be able to post with your name, but if you click on the post name, it won't give the correct information. 2. You can .......
297: Bottlehead Forum, RE: Ping Voltsecond (0.00)
Posted by VoltSecond on 2007-06-09, 15:01:25 (72.222.236.36)
On the "Normal" sheet "Desired dB minimum attenuation from Rseries" is used to calculate a resistor to put in series with switched attenuator to limit the volume at full volume. Play safe and play l .......
298: Bottlehead Forum, I don't think it will cure it. (0.00)
Posted by VoltSecond on 2007-06-03, 22:59:11 (72.222.236.36)
On the original sweet whispers I had a similar problem. I cleaned the switch contacts and it was OK for a while and then it came back. If flux from soldering is the problem, it may cure it. Play safe .......
299: Bottlehead Forum, You are welcome. (0.00)
Posted by VoltSecond on 2007-06-03, 00:15:15 (72.222.236.36)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
300: Bottlehead Forum, RE: Further question (0.00)
Posted by VoltSecond on 2007-06-02, 20:39:56 (72.222.236.36)
Try the 33K first. That is only about 4 dB less than what you had with 100K feeding 100K. If you want a bit more volume, solder the 80.6K across the 33K. Play safe and play longer! Don't be an "OUCH!" .......
301: Bottlehead Forum, RE: Ping Voltsecond (0.00)
Posted by VoltSecond on 2007-06-02, 15:25:04 (72.222.236.36)
If you used 100K series resistor with 100K pot before, use 15K with the sweetest whispers which is a 15K attenuator. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it an .......
302: Bottlehead Forum, Not ready for prime time (0.00)
Posted by VoltSecond on 2007-06-01, 20:53:20 (72.222.236.36)
Before MilliVolt came around, I was working on a shunt regulator page. Below is the link to the draft that never got finished. Send me asylum mail if you have questions or comments. Play safe and play .......
303: MagneQuest/Peerless Forum, Which Fe166 Horns are you using? (0.00)
Posted by VoltSecond on 2007-05-26, 17:38:42 (72.222.236.36)
Which Fe166 Horns are you using? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things vo .......
304: Bottlehead Forum, Just Five? (0.00)
Posted by VoltSecond on 2007-05-13, 14:30:13 (72.222.236.36)
(Doc sells good audio equipment at an affordable price)*5 Bonus: Doc's forum is full of people willing to help if you get stuck. Now for the tongue in cheek reasons: As Mom always said: "You can learn .......
305: MagneQuest/Peerless Forum, LED may be very bright for a short period of time. (0.00)
Posted by VoltSecond on 2007-05-06, 21:32:34 (72.222.236.36)
The 100th CCS for the filament is shown going through the LED. Most LEDs get unhappy with more than 10mA of current flow. A web search shows the 100th needs 6+ amps for the filament. Play safe and pla .......
306: High Efficiency Speaker Asylum, Has anyone lined the inside of a BK-16 with foam? (0.00)
Posted by VoltSecond on 2007-04-26, 22:10:11 (68.3.241.102)
I'm going to attempt building a BK-16. I'm close to a wizard with solder, but I can botch the assembly of an IKEA book case. Any thoughts on lining the bend reflectors and one of the short sides with .......
307: MagneQuest/Peerless Forum, We should make Mikey buy an armored Hummer! (0.00)
Posted by VoltSecond on 2007-04-24, 19:06:49 (68.3.241.102)
We need to keep our Candy Man in good health. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modify .......
308: MagneQuest/Peerless Forum, Re: Relationship between ra and parafeed primary (0.00)
Posted by VoltSecond on 2007-03-30, 20:43:59 (68.3.241.102)
My guess is it will work OK at 15K; however, I'd use it with DrP. See the spreadsheet in my web page. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (t .......
309: MagneQuest/Peerless Forum, Try 1K input 10K output (0.00)
Posted by VoltSecond on 2007-03-18, 20:26:59 (68.3.241.102)
Try 1K input 10K output (or better zero ohms input) I don't have a B7 to try, but lowering the drive impedance usually reduces the distortion at the output. Cores make a current distortion. This disto .......
310: Bottlehead Forum, Yep. I did the work on the K-12 too. (0.00)
Posted by VoltSecond on 2007-02-19, 19:07:10 (68.3.241.102)
I want to do an autobalance for it sometime too. Make sure you use ceramic sockets. I can smell the heat on the plastic ones. My hot-rodded, used to be a Paramour, plays just as loud and sounds better .......
311: Bottlehead Forum, Joe took some of the info on my site and made it prettier. (0.00)
Posted by VoltSecond on 2007-02-19, 18:09:24 (68.3.241.102)
Joe took some of the info on my site (with permission) and made it prettier. He must have run into a few of the people who made me want to take my site down. Note: I'm not very active right now becaus .......
312: MagneQuest/Peerless Forum, Contact me via asylum mail. (0.00)
Posted by VoltSecond on 2007-02-18, 19:43:49 (68.3.241.102)
Your asylum mail didn't work. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids .......
313: MagneQuest/Peerless Forum, Re: Output tranny power VS frequency (0.00)
Posted by VoltSecond on 2007-02-14, 18:11:58 (68.3.241.102)
Considering only saturation, if you double the frequency, you can get 4x the power out. HOWEVER, you'll can also get more than 4x the core loss and 4x the copper loss at 4X the power out. i.e. This me .......
314: High Efficiency Speaker Asylum, Re: Off Topic: It's a boy! (0.00)
Posted by VoltSecond on 2007-02-13, 18:36:13 (68.3.241.102)
Congrats! I did sign language for babies with MilliVolt. I highly recommend the "My Baby can Talk" video with baby Jessica. MilliVolt could sign months before she could talk and it really helped her a .......
315: MagneQuest/Peerless Forum, NY helpers (0.00)
Posted by VoltSecond on 2007-02-05, 19:03:03 (68.3.241.102)
If the helpers want, I'll credit them by name on the web site. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .......
316: MagneQuest/Peerless Forum, I'm confused. The frequency is log on the copy I have at home. (0.00)
Posted by VoltSecond on 2007-02-05, 18:59:16 (68.3.241.102)
1, 10, 100, 1000 are spaced log on the bottom of the graph on my copy. 10 is 1/3 the way to 1000. 100 is 2/3 the way to 1000. If your copy is different, we've got an excel compatibility problem to sol .......
317: MagneQuest/Peerless Forum, Putting in a big value for the DCR also works. (0.00)
Posted by VoltSecond on 2007-02-05, 18:44:31 (68.3.241.102)
The large value for the choke note came in before I added DCR to the model. I'll put that on my list of notes to fix. Thanks again for the feedback. Play safe and play longer! Don't be an "OUCH!" casu .......
318: MagneQuest/Peerless Forum, Thank you for the compliment. (nt) (0.00)
Posted by VoltSecond on 2007-02-05, 18:41:52 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
319: High Efficiency Speaker Asylum, Then buy a transient a happy meal to make the transfer. . .(nt) (0.00)
Posted by VoltSecond on 2007-02-03, 14:29:12 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
320: Bottlehead Forum, I wonder if distilled sounds better than tap? (nt) (0.00)
Posted by VoltSecond on 2007-02-03, 13:37:13 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
321: MagneQuest/Peerless Forum, Parafeed Web Site + New Excel Calculator (0.00)
Posted by VoltSecond on 2007-02-03, 13:34:49 (68.3.241.102)
Let me know if you think the Parafeed Web Site + New Excel Calculator is ready to move to my main page or if I need to polish it more. I'm planning to let Mikey copy the spreadsheet to his library onc .......
322: High Efficiency Speaker Asylum, I'd meet them at a McDonalds. (0.00)
Posted by VoltSecond on 2007-02-02, 19:41:24 (68.3.241.102)
I'd meet them at a McDonalds and trade the speakers for payment. The movers may decide to come back and move more than your DX3s. If you can afford Dx3s, you've probably got other goodies at home too. .......
323: SET Asylum, Be careful about power ratings (0.00)
Posted by VoltSecond on 2007-02-01, 19:25:03 (68.3.241.102)
Be careful about power ratings. 3 dB (twice the power) isn't that much louder. It's just a smidge louder. 10 dB (10x power) is significantly louder. Power is just one of many measurements we make on a .......
324: MagneQuest/Peerless Forum, 90SQ30 (0.00)
Posted by VoltSecond on 2007-02-01, 18:14:44 (68.3.241.102)
If you change your bridge to be four 90SQ20, you should pick up a volt or more on the output. I'd just solder the 90sq30's across the existing bridge. Digikey has them for $1.24 apiece in 10 pc qty. T .......
325: MagneQuest/Peerless Forum, Measure it and calculate (0.00)
Posted by VoltSecond on 2007-01-29, 19:31:26 (68.3.241.102)
Effective DCR secondary for PSUD II = Rsecondary + Rprimary * [Vsecondary {unloaded}/Vprimary]^2 You'll also have to be very very carefull and measure the unloaded secondary voltage. Or set V secondar .......
326: MagneQuest/Peerless Forum, Re: Voltseconds, got one more question (0.00)
Posted by VoltSecond on 2007-01-24, 20:57:29 (68.3.241.102)
1. Assume zero current in R5 and R7 and calculate normally. 2. If you solder the plate of the two tubes together and at the same time solder the cathodes together, one tube can hog the bias current. B .......
327: MagneQuest/Peerless Forum, oops, I wasn't scrolling down (0.00)
Posted by VoltSecond on 2007-01-23, 17:55:18 (68.3.241.102)
R5 and R7 couple the ac current from driving the primary into the cathode of the tubes. This makes the voltage on the cathode of the tube change less and thus the tube will have a Rp closer to having .......
328: MagneQuest/Peerless Forum, DrP (Damped Resonance Parafeed) (0.00)
Posted by VoltSecond on 2007-01-22, 18:59:28 (68.3.241.102)
The following is not criticism of Parafeed, it is a discussion of how to avoid POTENTIAL problems using Parafeed. Any, and I do mean any, circuit has trade offs and options. I like having options. The .......
329: MagneQuest/Peerless Forum, 79.5k is what you'll want with the .66u cap (0.00)
Posted by VoltSecond on 2007-01-21, 18:48:43 (68.3.241.102)
The DrP resistor isn't very sensitive to its value. 75K to 82K should work. If you want lower peaking, the DrP capacitor has to be about 1 u instead of .66U. The damping with .66u should be good enoug .......
330: MagneQuest/Peerless Forum, I'd Try DrP across C1+ Excel Spread Sheet (0.00)
Posted by VoltSecond on 2007-01-21, 14:50:58 (68.3.241.102)
Add a .66 uF cap with a series resistor across C1 to damp the tank made by C1 and the BCP-16. I've been playing with a Parafeed spread sheet and it is on the web site below. I'm not done tweaking the .......
331: High Efficiency Speaker Asylum, Re: Is there such a thing as small efficient speakers? (0.00)
Posted by VoltSecond on 2007-01-20, 09:21:00 (68.3.241.102)
The Bottlehead SEXY speaker may work for you. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modify .......
332: MagneQuest/Peerless Forum, Does it have to be PP? (0.00)
Posted by VoltSecond on 2007-01-17, 19:19:39 (68.3.241.102)
I paralleled two plates in a single envelope in one of my Headphone amps. This is the amp that sounded the best, but it didn't have enough gain to be run from a portable CD player (A 115V player could .......
333: Bottlehead Forum, You deserve it! (nt) (0.00)
Posted by VoltSecond on 2007-01-11, 20:05:27 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
334: MagneQuest/Peerless Forum, It is Push-Pull (0.00)
Posted by VoltSecond on 2007-01-08, 19:43:27 (68.3.241.102)
At 1 kHz the caps will be shorts. With ideal tubes and an ideal transformer, the center tap of the transformer will not have any ac voltage on it even at full power, that one thing that makes it push- .......
335: MagneQuest/Peerless Forum, Yep, the cap values double. (0.00)
Posted by VoltSecond on 2007-01-08, 10:39:50 (68.3.241.102)
Yep, the cap values double. A parafeed transformer is not suitable for push-pull. There are many ways to optomize transformers. If a transformer is optomized for single ended, it often does not work w .......
336: MagneQuest/Peerless Forum, Re: Parafeed PP (0.00)
Posted by VoltSecond on 2007-01-07, 18:24:04 (68.3.241.102)
The plate impedance for PP class A (which you are doing) is twice the load impedance for single ended one tube for either parafeed PP or normal PP. Don't sweat if you calculate you need 10K and can on .......
337: Bottlehead Forum, Re: Ping Voltsecond (0.00)
Posted by VoltSecond on 2007-01-06, 18:27:38 (68.3.241.102)
The advantage to the "easiest" over "typical" is that when the wiper goes open, you still have some attenuation instead of no attenuation. Play safe and play longer! Don't be an "OUCH!" casualty. Unpl .......
338: Bottlehead Forum, Add two resistors. (0.00)
Posted by VoltSecond on 2007-01-03, 17:57:03 (68.3.241.102)
Put a resistor in series with each end of the winding (two resistors total) where each resistor drops about 1.4V. This will drop the voltage and also limit the inrush current into the tube. Play safe .......
339: Bottlehead Forum, The HAMs at work complain about high failure rates with voltage doublers. (0.00)
Posted by VoltSecond on 2006-12-24, 19:09:43 (68.3.241.102)
The HAMs at work complain about high failure rates with voltage doublers. 325 - 0 - 325 volt transformers may not have enough insulation to be run as a voltage doubler (about 730V dc output). The >170 .......
340: Bottlehead Forum, I have a buddy who breaks in caps with 115V and individual light bulbs. (0.00)
Posted by VoltSecond on 2006-12-22, 19:39:13 (68.3.241.102)
I have a buddy who breaks in high voltage caps with 115V 60 Hz and individual light bulbs. A 20 uF motor run cap will draw about .86A or about 99 VA with 115V ac on it. I'm not sure what wattage bulb .......
341: High Efficiency Speaker Asylum, I just bought 3 pounds of Kester 44 just to avoid lead free. (0.00)
Posted by VoltSecond on 2006-12-20, 10:16:20 (68.3.241.102)
Lead free doesn't solidify to look shiny. It looks dull, but not grainy. If you have a good meniscus and a smooth matt surface, you've got the joint as good as it will get. I just bought 3 pounds of K .......
342: Bottlehead Forum, It is supposed to help golf balls. (0.00)
Posted by VoltSecond on 2006-12-19, 20:04:13 (68.3.241.102)
I tried a pair of Cryo tubes a long time ago. I couldn't tell if the differences were from the brand of tubes or from the treatment. It would be great if someone with a curve traces could do a before .......
343: Bottlehead Forum, We'll miss you Terry. Say hello to Buddha and Gizmo for us. (0.00)
Posted by VoltSecond on 2006-12-11, 18:45:54 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
344: MagneQuest/Peerless Forum, Re: About to begin construction (0.00)
Posted by VoltSecond on 2006-12-01, 19:08:54 (68.3.241.102)
Every transformer I know of can take being biased 60V above ground for a 2A3 cathode if the output of the transformer is connected to the ground used for the 2a3 bias resistor. Play with the cathode c .......
345: SET Asylum, To double the apparent loudness of music takes 8 - 10 dB more power. (0.00)
Posted by VoltSecond on 2006-11-30, 19:55:26 (68.3.241.102)
You own the amp and speakers. Listen to them. If your happy, pour your self a glass of Balvenie Double Wood, sit down and relax to music. If you still want to scratch the "speaker itch", bring your ol .......
346: Bottlehead Forum, Single point ground (0.00)
Posted by VoltSecond on 2006-11-29, 18:05:34 (68.3.241.102)
A single point ground works best below 100 kHz. Grounding everywhere works best above 10 MHz. In between is when PJ earns his keep! ;-] The frequency you worry about isn't just the frequency you are u .......
347: MagneQuest/Peerless Forum, 50 Hz is more of the problem than 230V (0.00)
Posted by VoltSecond on 2006-11-27, 18:21:13 (68.3.241.102)
The PC should have an 115V/230V switch. I suspect the flat screen will too. Switchers don't care much about line frequency. The audio toys could be a problem. At 50Hz, a marginal 115V transformer can .......
348: MagneQuest/Peerless Forum, Bugle 205D in my spreadsheet (0.00)
Posted by VoltSecond on 2006-11-21, 21:06:21 (68.3.241.102)
On paper, 375V, 22 mA bias, 10K load gives 1.3W out. Interesting, at 375V 10K, less bias current gives more power out. At 375V, 30 mA, 10K I only expect 1W out. I'm not sure which will sound the best. .......
349: High Efficiency Speaker Asylum, I'd go for 16. (0.00)
Posted by VoltSecond on 2006-10-15, 19:44:58 (68.3.241.102)
I don't have the numbers for the D-90 so I'll guess it is wound so the damping factor is the same for the 4 and 16 ohm output taps into rated load. The effective damping factor with a 10 foot run of s .......
350: Tube DIY Asylum, I get that with most things I model. (0.00)
Posted by VoltSecond on 2006-10-10, 20:56:36 (68.3.241.102)
I get oddness with most things I model both tube and solid state. BJTs seem to work the best. Pentode models seem to be worse than others with respect to the screen interaction. If you don't forward b .......
351: Bottlehead Forum, Without bleeders it could be weeks (no kidding) (nt) (0.00)
Posted by VoltSecond on 2006-10-10, 20:20:57 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
352: High Efficiency Speaker Asylum, How about a series of individual pipes (0.00)
Posted by VoltSecond on 2006-10-09, 21:16:51 (68.3.241.102)
How about a series of individual pipes resonant at each note on the piano for a propane powered spectrum analyzer. A bit of internal damping may attenuate higher harmonics. Play safe and play longer! .......
353: MagneQuest/Peerless Forum, Re: Help with EXO-173 P-P amp (0.00)
Posted by VoltSecond on 2006-10-09, 21:11:46 (68.3.241.102)
I couldn't view the scope photos. A couple quick notes: Pull the 6A5Gs and see if it rings without them. If the ringing frequency changes that is a clue the tubes are part of the issue. Try a resistor .......
354: Bottlehead Forum, The clips need to be well insulated (0.00)
Posted by VoltSecond on 2006-10-09, 20:54:47 (68.3.241.102)
The clips, solder joints to the resistor, and resistor leads all need to be insulated. The only exposed metal on the clip-resistor set up should be the tip of the contact point. I always use two piece .......
355: MagneQuest/Peerless Forum, Tap hopping (0.00)
Posted by VoltSecond on 2006-10-08, 11:30:14 (68.3.241.102)
On most 8 ohm speakers, I prefer to use the 4 ohm tap on my Dyna MK IIIs instead of the 8 ohm tap. It sounds cleaner and the bass is a bit tighter. Play safe and play longer! Don't be an "OUCH!" casua .......
356: MagneQuest/Peerless Forum, I got slightly different numbers for the upper -3db point. (0.00)
Posted by VoltSecond on 2006-10-08, 11:27:29 (68.3.241.102)
From P.J.'s post: Here's an example: Assume a transformer with ____20 henries inductance, ____500 ohms total resistance (referred to the primary), ____20mH leakage inductance, and ____1000pF capacitan .......
357: Tube DIY Asylum, I'm still using the Msim 9.1 demo (0.00)
Posted by VoltSecond on 2006-10-08, 09:43:09 (68.3.241.102)
Brown bag spice has been recommended to me, but I haven't tried it or LTSpice at this point. I hear the author for LTSpice is receptive to suggestions for improvement, you may want to email him your p .......
358: Tube DIY Asylum, The zener will regulate better (0.00)
Posted by VoltSecond on 2006-10-03, 19:13:14 (68.3.241.102)
6.2V zeners are a stand out in zeners. They are high enough in voltage they regulate well and are low impedance. The are low enough in voltage they are reasonably low noise. Play safe and play longer! .......
359: Tube DIY Asylum, It will work better with a cap from B+ to the grid of the tube. (0.00)
Posted by VoltSecond on 2006-10-01, 19:36:30 (68.3.241.102)
Heres two more options for shunt regulators. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifyi .......
360: Tube DIY Asylum, Use the base that accepts the shields. (0.00)
Posted by VoltSecond on 2006-10-01, 13:31:08 (68.3.241.102)
Use the base that accepts the shields and try it both ways. The amp will have stage to stage and channel to channel cross talk to worry about as well as RF pick up. The power supply is only potential .......
361: SET Asylum, It changes the amp's performance characteristics. (0.00)
Posted by VoltSecond on 2006-10-01, 13:21:32 (68.3.241.102)
I like the "Makes all sorts of things possible, and offers the opportunity to screw the same things up beyond belief" explanation. Here's a more verbose one: Negative feedback uses some to nearly all .......
362: MagneQuest/Peerless Forum, Nice! (nt) (0.00)
Posted by VoltSecond on 2006-09-29, 19:45:15 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
363: High Efficiency Speaker Asylum, 70 Hz refresh rate may help with the monitor. (nt) (0.00)
Posted by VoltSecond on 2006-09-03, 22:35:27 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
364: High Efficiency Speaker Asylum, Edge Crash (0.00)
Posted by VoltSecond on 2006-09-03, 11:12:07 (68.3.241.102)
I tried running edge on my 98SE machine and I got a fatal exception/ blue screen of death. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) befor .......
365: High Efficiency Speaker Asylum, 4 dB isn't a lot more. (0.00)
Posted by VoltSecond on 2006-08-26, 15:36:57 (68.3.241.102)
4 dB isn't a lot more volume. An active sub with a passive line level crossover may get you there with the 166. You won't work the tube amp as hard with the bass so more is there for everything else. .......
366: Bottlehead Forum, Reel Love (nt) (0.00)
Posted by VoltSecond on 2006-08-16, 19:45:29 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
367: Bottlehead Forum, Reel Fetish . . . and other ideas (0.00)
Posted by VoltSecond on 2006-08-16, 18:58:29 (68.3.241.102)
I didn't read the suggestions already posted to see if these are duplicates "G rated names" * Reel Music . Music Reel . Reel Truth . Audio Reel . Top Reel . Real to Reel . Reel food . Reel Supply . Ta .......
368: Bottlehead Forum, I'm surprised, but I've been surprised before. (0.00)
Posted by VoltSecond on 2006-07-19, 22:50:06 (68.3.241.102)
I'm surprised, but I've been surprised before. I would have expected that all grounds are common at the preamp input only and the shield attached to the metal grid around the mic, but not attach to th .......
369: Bottlehead Forum, Kibitz (0.00)
Posted by VoltSecond on 2006-07-19, 20:11:42 (68.3.241.102)
If the shields are grounded only at one end, tie the floating end of the shield to the nearest ground and the ground to the frame/ chassis with a 0.1 uF or 0.01 uF cap (I normally use ceramic for this .......
370: MagneQuest/Peerless Forum, Hi-volts get interesting. (0.00)
Posted by VoltSecond on 2006-07-08, 10:14:44 (68.3.241.102)
I've built one 40kV brass board and over the years have 6, 10, 12 and 14 kV power supplies in production. Getting high voltage magnetics that last for years isn't easy. Like most companies, my employm .......
371: MagneQuest/Peerless Forum, 50 mil test point (0.00)
Posted by VoltSecond on 2006-07-07, 19:00:51 (68.3.241.102)
I know from experiance that across an very clean insulator, a gap of 50 mils arcs at just under 1500V rms 60 Hz. As the insulator gets dirty or dusty, it arcs at a lower voltage. This is a "creepage" .......
372: MagneQuest/Peerless Forum, Re: any possible solution? (0.00)
Posted by VoltSecond on 2006-07-06, 22:09:35 (68.3.241.102)
Generally with a simple wax or varnish job, the insulation system will support 20V/mil through the insulation and 10V/mil across the surface of the insulation for long durations. If we assume this is .......
373: MagneQuest/Peerless Forum, That's kind of high. (0.00)
Posted by VoltSecond on 2006-07-04, 21:15:31 (68.3.241.102)
If the bobbin is 90 mil thick on all sides and 100 mil airgap over bobbin, you've got a chance. However, standard bobbin thickness' run 40 mil and the bobbins are wound full. Play safe and play longer .......
374: MagneQuest/Peerless Forum, Re: FS-100pf choke insulation (0.00)
Posted by VoltSecond on 2006-07-04, 20:06:29 (68.3.241.102)
The case must be grounded for safty. How high are you trying to run the choke? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch .......
375: Bottlehead Forum, 3. Whats with the low frequency pickup in the Seduction? (0.00)
Posted by VoltSecond on 2006-06-18, 23:22:36 (68.3.241.102)
Are you talking about record warp pick up? If so, I thought I saw a post for a subsonic filter for the seduction quite some time ago. Note: MilliVolt is doing well and is still keeping me busy. She do .......
376: MagneQuest/Peerless Forum, Low overhead voltage (battery bias) poses a problem. (0.00)
Posted by VoltSecond on 2006-06-11, 23:05:19 (68.3.241.102)
The battery's voltage will drop with time causing the circuit to quickly lose headroom. Also, the CCS'd plate's bias points will vary from tube to tube. Because of these two issues, something that loo .......
377: MagneQuest/Peerless Forum, Have you considered a CCS? (nt) (0.00)
Posted by VoltSecond on 2006-06-09, 18:19:09 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
378: MagneQuest/Peerless Forum, Re: DC resistance and maximum current (0.00)
Posted by VoltSecond on 2006-05-25, 21:53:19 (68.3.241.102)
Saturation current (I) and DCR are independent variables. Ac^2 * Aw/ MTL = pd^2 * { (LI)^2/ DCR }/[ Kc * (Ur * H)^2 * (Ap/ Aw) ] Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, dis .......
379: Tube DIY Asylum, Hints for Zobel between Anode and Screen Taps (0.00)
Posted by VoltSecond on 2006-05-25, 21:45:52 (68.3.241.102)
Hints 1. Do your testing open loop so you can isolate the tranny issues from feedback issues. 2. Carefully add a cap between windings to find the connection that changes the frequency of the ring. If .......
380: MagneQuest/Peerless Forum, If you do get the 5 ohm version. . . (0.00)
Posted by VoltSecond on 2006-05-24, 20:43:17 (68.3.241.102)
If you do get the 5 ohm version, make sure your tranny's secondary is less than 5 ohms so you get the true benefit of the low ohms in the choke. Play safe and play longer! Don't be an "OUCH!" casualty .......
381: MagneQuest/Peerless Forum, I'd pick the one with the lower capacitance (0.00)
Posted by VoltSecond on 2006-05-23, 21:11:27 (68.3.241.102)
52 ohms at 125 mA is 6.50V drop. 5 ohms at 123 mA is 0.625V drop. 10 H is about twice the critical inductance for 720V dc output at 125 mA. 52 ohms will get us better than 0.5% regulation half load to .......
382: Tube DIY Asylum, UL Connection idea (0.00)
Posted by VoltSecond on 2006-05-21, 22:52:33 (68.3.241.102)
I've got one of those ideas that pops into your head and your sure someone's already tried it: In a pentode output stage with UL taps: Has anyone tried dropping the voltage on the ultra linear taps ab .......
383: MagneQuest/Peerless Forum, Re: 45 parafeed with resistor load (0.00)
Posted by VoltSecond on 2006-05-18, 21:02:12 (68.3.241.102)
How about a crazy high voltage with a plate bias resistor 4 times the reflected load? (Brute force CCS.) B+ will definately have to be delayed until the filaments to heat up. Play safe and play longer .......
384: Tube DIY Asylum, Have you seen the video? Yep! (0.00)
Posted by VoltSecond on 2006-05-17, 20:32:51 (68.3.241.102)
I've worked on small HV designs that once you strike the arc it will pull pretty far on 35W dc. Oh well, then I had to fix the protection circuit so it would kill the arc faster. Play safe and play lo .......
385: Tube DIY Asylum, Just say Ouch. (0.00)
Posted by VoltSecond on 2006-05-17, 19:17:30 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warranty. ::: TOPIC:: .......
386: Tube DIY Asylum, 1N5908 (0.00)
Posted by VoltSecond on 2006-05-13, 20:06:13 (68.3.241.102)
I was searching for an old post of mine and ran across this discussion about zeners. The 1N5908 is a mosorb / transorb / transient suppressor that works well as a 6.2V zener dissipating up to about 1. .......
387: Bottlehead Forum, Something sounds very wrong. (0.00)
Posted by VoltSecond on 2006-05-11, 21:26:43 (68.3.241.102)
Ohm from the power cord to chassis and from the power cord to RCA plugs on all units in your system. You may have a 115V hot wire touching chassis. Play safe and play longer! Don't be an "OUCH!" casua .......
388: Bottlehead Forum, Use them in series, unless you match everything. (0.00)
Posted by VoltSecond on 2006-04-16, 21:42:31 (68.3.241.102)
In parallel: If the gains aren't exactly matched for gain, the amps fight each other through their output impedances. With two tube amps, each with two tubes, this requires that 4 tubes and all the ga .......
389: MagneQuest/Peerless Forum, How good do you need it? (0.00)
Posted by VoltSecond on 2006-04-15, 17:07:31 (68.3.241.102)
How good do you need it? Get a 24V and make a virtual ground with pre-load divider resistors. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) be .......
390: MagneQuest/Peerless Forum, Industrial Suppliers (0.00)
Posted by VoltSecond on 2006-04-14, 21:35:07 (68.3.241.102)
I deal with a few magnetics suppliers that have a base cost + materials surcharge. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you to .......
391: Bottlehead Forum, Put a cup of marbles in the freezer. (0.00)
Posted by VoltSecond on 2006-04-05, 20:46:47 (68.3.241.102)
To get teenagers out of bed, put a cup of marbles in the freezer. If they don't get up, toss the marbles and the cup in bed with them. Have them bring the cup of marbles back to the kitchen if they wa .......
392: MagneQuest/Peerless Forum, So. . . How much tritium do you need to make a dial visibly glow in day light? (0.00)
Posted by VoltSecond on 2006-03-27, 19:58:38 (68.3.241.102)
So. . . How much tritium do you need to make a dial visibly glow in day light? Tritium in the dial, cobalt in the trannies. . .Expect to see men wearing dark glasses at your door step soon. Play safe .......
393: Bottlehead Forum, What flux is in your solder? (0.00)
Posted by VoltSecond on 2006-03-25, 09:50:32 (68.3.241.102)
With Kester 44 flux, I haven't had many problems wetting the joints with a clean soldering iron tip. I've had problems with other fluxes. Note: Europe is outlawing Tin-Lead solder. It is affecting us .......
394: General Asylum, Get your 63/37 Kester 44 while you can. (0.00)
Posted by VoltSecond on 2006-03-18, 19:34:10 (68.3.241.102)
Get your 63/37 Kester 44 while you can. I still haven't seen studies that show if the new solders have solved the work hardening and dendrite problems. Play safe and play longer! Don't be an "OUCH!" c .......
395: Bottlehead Forum, Questions: (0.00)
Posted by VoltSecond on 2006-03-11, 14:19:58 (68.3.241.102)
1. With the turntable off but plugged in with the seduction etc on, do you get the thumps? 1.1 If you don't, turn the table on, but leave the tone arm on the arm rest and repeat. 2. Are they low frequ .......
396: MagneQuest/Peerless Forum, I haven't look at this spreadsheet in years. (0.00)
Posted by VoltSecond on 2006-03-09, 20:25:07 (68.3.241.102)
Stepped Attenuator Excel Link. I haven't look at this spreadsheet in years. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. .......
397: Bottlehead Forum, If used as current sources, Yes. If voltage sources, No. (0.00)
Posted by VoltSecond on 2006-02-28, 20:15:15 (68.3.241.102)
If used as current sources, yes, they share nicely. To hook LM317's up in parallel as current sources just tied the adjust and input pins in parallel and hook the output pins and current set resistors .......
398: Bottlehead Forum, Do you have an oscilloscope? (nt) (0.00)
Posted by VoltSecond on 2006-02-20, 19:37:27 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
399: Bottlehead Forum, Universal Snubber Arrangement (0.00)
Posted by VoltSecond on 2006-02-19, 20:59:55 (68.3.241.102)
Universal Snubber Arrangement (Image borrowed from one of my web pages for a specific amplifier.) This arrangement can hammer any transformer/diode into submission! ;-} I like this arrangement better .......
400: Bottlehead Forum, GET WELL! Try to do what the nurses say to do too. (0.00)
Posted by VoltSecond on 2006-02-13, 19:35:23 (68.3.241.102)
GET WELL! The world is smaller without you participating in it. Try to do what the nurses say to do too. They actually know what they are doing. Play safe and play longer! Don't be an "OUCH!" casualty .......
401: Bottlehead Forum, It is a good ideal to feed the cable with a resistor or inductor. (0.00)
Posted by VoltSecond on 2006-02-12, 13:02:33 (68.3.241.102)
It is a good ideal to feed the cable with a resistor or inductor. This breaks up a current loop made by the capacitors in the amp and the capacitors in the power supply. Braid the B+ and returns as on .......
402: Bottlehead Forum, It is amazing how little it takes sometimes to help out. (0.00)
Posted by VoltSecond on 2006-02-11, 20:02:44 (68.3.241.102)
It is amazing how little it takes sometimes to help out. -Volt. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. .......
403: General Asylum, A different way to look at the numbers. (0.00)
Posted by VoltSecond on 2006-02-03, 20:50:25 (68.3.241.102)
I agree that EMI on the mains (RF and audio frequency electrical pollution) is a problem; however, the caps may not be as hopeless as you think. A capacitor's resonant frequency is where the cap turns .......
404: Bottlehead Forum, Iron thumb (0.00)
Posted by VoltSecond on 2006-01-24, 19:20:20 (68.3.241.102)
The load on a output triode varies from 2 to 14 times R sub p (Rp). Use 5 as a typical number. Example Rp = 900 ohms so Rload = 4500 ohms = 4.5 kohm The plate choke on a tube should be around 10 times .......
405: Bottlehead Forum, It's not a tone control or bass boost. (0.00)
Posted by VoltSecond on 2006-01-18, 19:17:30 (68.3.241.102)
Try it with inexpensive parts first. If you like it, keep it or upgrade the parts. If not, take it out. Inexpensive iron tends to benefit more from DrP (Damped Resonance Parafeed) than high end Magneq .......
406: Bottlehead Forum, Iron Tower Trilogy (0.00)
Posted by VoltSecond on 2006-01-17, 20:11:52 (68.3.241.102)
A Tolkien style book worth reading is the Iron Tower Trilogy by McKiernan. It's an easier read than actual Tolkien. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and .......
407: Bottlehead Forum, It is complex to explain (0.00)
Posted by VoltSecond on 2006-01-13, 15:24:48 (68.3.241.102)
DrP's electrical action is complex to explain. Try it with cheap parts first. If you like it, install it more permanently with better parts. The cap with the series resistor needs to be the same value .......
408: Bottlehead Forum, In most shunt regulators. . .In most shunt regulators the parasitics work for you instead of against you. (0.00)
Posted by VoltSecond on 2006-01-13, 14:39:52 (68.3.241.102)
In most shunt regulators the parasitics work for you instead of against you. With a passive element to the raw B+, things (like PSRR) get better as frequency goes up. With a series regulator, parasiti .......
409: MagneQuest/Peerless Forum, Same vendor same value chokes usually not a problem. (0.00)
Posted by VoltSecond on 2006-01-13, 14:31:27 (68.3.241.102)
Different value chokes can have a nasty series resonance. The parasitic capacitance of one goes series resonant with the inductance of another one. During series resonance, the LC tank looks like a sh .......
410: Bottlehead Forum, Paramour Bass Tightner version 2 (0.00)
Posted by VoltSecond on 2006-01-12, 20:33:29 (68.3.241.102)
Many speakers have an impedance peak in the bass region. Parafeed circuits can have a bass resonance that involves the parafeed capacitor, the plate choke and the output transformer's primary inductan .......
411: Bottlehead Forum, Cool. (0.00)
Posted by VoltSecond on 2006-01-12, 16:12:02 (68.3.241.102)
Now she can use "Where's that darn 1W 1K" in the proper context! Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. .......
412: Bottlehead Forum, I tossed a quick web page up that may help. (0.00)
Posted by VoltSecond on 2006-01-11, 20:21:01 (68.3.241.102)
Send me Asylum Mail if you have questions or comments. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remembe .......
413: MagneQuest/Peerless Forum, Advice (0.00)
Posted by VoltSecond on 2006-01-03, 21:21:13 (68.3.241.102)
It is hard to tell how bad it is without seeing how much damage was done. If you simply split the outer layer of insulation, no big deal. But if you nicked the wires under it, that's usually bad news. .......
414: MagneQuest/Peerless Forum, I've made autoformers out of filament transformers. (0.00)
Posted by VoltSecond on 2006-01-02, 17:21:23 (68.3.241.102)
I've made autoformers out of filament transformers, both step up and step down. I needed the step up when a darn expensive digital piece of test gear was 5V ac short of the voltage I needed on "low ra .......
415: Bottlehead Forum, Do you need the 5V for a filament? (0.00)
Posted by VoltSecond on 2006-01-02, 12:29:57 (68.3.241.102)
If not, hook the 5V up as a voltage doubler attached to ground. You don't need R1, R2 and R3 in the picture on a 5V winding. Then put the 230V on top of the 5V voltage doubler output. Do not hook the .......
416: Bottlehead Forum, Good Wife! (0.00)
Posted by VoltSecond on 2006-01-01, 14:18:58 (68.3.241.102)
For Christmas, Mrs. Volt gave me both Morgan Jones' "Building Valve Amplifiers" and Morgan Jones' "Valve Amplifiers, 3rd ed." What a lady! I'm 1/2 way through the first and 1/3 the way through the sec .......
417: MagneQuest/Peerless Forum, I agree with PJ. Also, a few volts change on the ac can make a difference. (0.00)
Posted by VoltSecond on 2006-01-01, 10:05:52 (68.3.241.102)
I agree: If one of the diodes in the amp is bad or weak, the transformer will buzz. Also: Badly imbalanced dc winding resistances in a center tapped transformer can also cause buzz. Note: Line voltage .......
418: MagneQuest/Peerless Forum, Measure the DC component on the 115V. Do not touch exposed metal on probes! (0.00)
Posted by VoltSecond on 2005-12-29, 21:14:48 (68.3.241.102)
Measure the DC component on the 115V. Do not touch exposed metal on probes! It'll ruin your day. . .forever. If possible, take it to a friends house on the other side of town and see if it buzzes ther .......
419: MagneQuest/Peerless Forum, Buzz from the transformer or from speakers? (nt) (0.00)
Posted by VoltSecond on 2005-12-25, 21:37:01 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
420: Bottlehead Forum, Who makes that speaker? Mrs Volt actually liked it! (0.00)
Posted by VoltSecond on 2005-12-25, 21:30:55 (68.3.241.102)
I'm not getting out or soldering much since MilliVolt arrived. So I have to ask: Who makes that speaker? Mrs. Volt actually liked it! Play safe and play longer! Don't be an "OUCH!" casualty. Unplug i .......
421: MagneQuest/Peerless Forum, CCS the first two tubes. (0.00)
Posted by VoltSecond on 2005-12-22, 20:05:56 (68.3.241.102)
I assume th 6L6 is hooked up in triode mode. You probably don't need the input cap. CCS the first two tubes. At least CCS the cathode follower. Play safe and play longer! Don't be an "OUCH!" casualty .......
422: MagneQuest/Peerless Forum, Safety (0.00)
Posted by VoltSecond on 2005-12-20, 20:55:21 (68.3.241.102)
Safety is the only reason I know of not to connect it up with the primary going to the cathode of the output tube. If there is a primary to secondary short in the transformer. The primary voltage can .......
423: Bottlehead Forum, Good one PJ! (0.00)
Posted by VoltSecond on 2005-12-19, 10:02:52 (68.3.241.102)
Add a few more soap boxes to that one: 1. Speaker impedance? 8 ohm! Ahem cough! cough!) 2. Headphone impedance (Argh!. . .12 to 600 ohms. . .Argh!) Play safe and play longer! Don't be an "OUCH!" casua .......
424: MagneQuest/Peerless Forum, Use a pentode for the input (ala Gary Pimm) (0.00)
Posted by VoltSecond on 2005-12-17, 15:08:45 (68.3.241.102)
The plate of the input pentode is cap coupled to the grid of the output pentode. The input pentode's plate bias resistor runs between the plates of the input to output pentode to form a primary side, .......
425: Bottlehead Forum, I agree. 140V is way too high. (0.00)
Posted by VoltSecond on 2005-12-16, 19:27:48 (68.3.241.102)
That's high enough to cause problems with you appliances too. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . . .......
426: MagneQuest/Peerless Forum, The choke had parasitic capacitances (0.00)
Posted by VoltSecond on 2005-12-06, 17:42:55 (68.3.241.102)
The choke had parasitic capacitances across it, to its mounting tabs and to the outside world around it. Placing the resistor on the tube side of the choke usually minimizes the effect of these capaci .......
427: Bottlehead Forum, Quick Advise / Standard Tube Amp Mods (0.00)
Posted by VoltSecond on 2005-12-05, 20:30:28 (68.3.241.102)
Standard Tube Mods: You have to give up considerable voltage to shunt regulate. The shunt regulator will have to accept line voltage changes with out cooking or running "dry" on current. Here in Phoen .......
428: MagneQuest/Peerless Forum, Sounds very cool. (0.00)
Posted by VoltSecond on 2005-12-05, 19:19:38 (68.3.241.102)
Sounds very cool. I've got a pair of 4 and 16 ohm speaker I've been eyeing up and that would mean I could drive it with my 8 ohm output amps. Play safe and play longer! Don't be an "OUCH!" casualty. U .......
429: MagneQuest/Peerless Forum, No B+ change, but a resistor change is needed. (0.00)
Posted by VoltSecond on 2005-12-05, 18:06:02 (68.3.241.102)
The old plate resistor on the 6SN7 was 24K. The choke DCR is 6.9K. So pull the 24K out, replace it with the choke with a 17.1K series resistor and your bias will be the same. You should be able to mea .......
430: MagneQuest/Peerless Forum, Mike, is there a 4, 8, 16 autoformer in the stable? (0.00)
Posted by VoltSecond on 2005-12-04, 16:38:21 (68.3.241.102)
Mike, is there a 4, 8, 16 autoformer in the stable? It'd be a nice thing to have around when the speaker is designed for a different amplifer than what you have. Play safe and play longer! Don't be an .......
431: Bottlehead Forum, Make R13 and R20 470K (0.00)
Posted by VoltSecond on 2005-11-30, 19:46:13 (68.3.241.102)
On the pots, jumper pin 1 to pin 3 Make R13 and R20 470K Make R14 and R21 10K Gary told me that if I take the ground side of C16 and C18 to the cathode of the output tubes (pin 8 and pin 3) that it wo .......
432: MagneQuest/Peerless Forum, I'm lazy tonight. I'll estimate 1000x the cap plate to ground. (0.00)
Posted by VoltSecond on 2005-11-29, 19:58:14 (68.3.241.102)
With the parafeed OPT primary connected to the bias resistor, the cathode bypass cap requirement is dominated by the capacitance from the output tube from plate to ground. This capacitance comes from .......
433: Bottlehead Forum, As a buffer, no volume control (0.00)
Posted by VoltSecond on 2005-11-29, 17:32:47 (68.3.241.102)
As a buffer, no volume control, you could get an input impedance as high as 1 meg. I'd go a bit lower and use 470K. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and .......
434: Bottlehead Forum, As a buffer, no volume control (0.00)
Posted by VoltSecond on 2005-11-29, 17:32:37 (68.3.241.102)
As a buffer, no volume control, you could get an input impedance as high as 1 meg. I'd go a bit lower and use 470K. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and .......
435: MagneQuest/Peerless Forum, Run it without the 500 ohms to start. (nt) (0.00)
Posted by VoltSecond on 2005-11-28, 20:02:46 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
436: MagneQuest/Peerless Forum, Re: That sounds high. (0.00)
Posted by VoltSecond on 2005-11-28, 20:01:31 (68.3.241.102)
Yes, the cathode resistor and bypass cap affect the sound. With the OPT grounded to the cathode side of the bias resistor, the bypass cap doesn't affect the sound much and actually can be a smaller va .......
437: MagneQuest/Peerless Forum, That sounds high. (0.00)
Posted by VoltSecond on 2005-11-27, 12:21:26 (68.3.241.102)
Do the hum readings drop if you ground the grid to the output tube? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh .......
438: MagneQuest/Peerless Forum, I didn't have the problem the times I've tried it. (0.00)
Posted by VoltSecond on 2005-11-26, 12:59:42 (68.3.241.102)
Does a voltmeter register any ac voltage to ground where the OPT is attached on the bias resistor? Is the OPT iron grounded? Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, dischar .......
439: Bottlehead Forum, Good Point. I'll update the note. (0.00)
Posted by VoltSecond on 2005-11-26, 12:55:51 (68.3.241.102)
Note: You should have the same or more money in your software (CDs/ LPs) that you do in your main system's hardware. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it an .......
440: Bottlehead Forum, My wife's stuff. . .However she wants it. My / Our stuff: (0.00)
Posted by VoltSecond on 2005-11-26, 10:51:10 (68.3.241.102)
My wife's stuff. . .However she wants it. My / Our stuff: Classical..........Alphabetical by composer Jazz ...............Alpha by performer (other than MapleShade) Rock...............Alpha by perform .......
441: Bottlehead Forum, 45 degree Reflector on top (0.00)
Posted by VoltSecond on 2005-11-24, 12:38:19 (68.3.241.102)
You could try 45 degree Reflector on top. A large marble floor tile comes to mind (flat and heavy). Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twi .......
442: MagneQuest/Peerless Forum, Flossing is good. (0.00)
Posted by VoltSecond on 2005-11-21, 20:44:02 (68.3.241.102)
1. Heater switch was to change phase between the heater windings of the two tubes with the hope of getting some cancellation that way. 2.1 Flossing is good; however, I don't know may people who actual .......
443: MagneQuest/Peerless Forum, Ideas (0.00)
Posted by VoltSecond on 2005-11-20, 09:33:20 (68.3.241.102)
1. Install a switch to swap the polarity of the heater on one tube of the Diff pairs. Then for a given set of tubes, you can find the best hum null with only 2 (or 4 if the drivers are switched) switc .......
444: Bottlehead Forum, Have fun with the TSA (nt) (0.00)
Posted by VoltSecond on 2005-11-18, 17:37:59 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
445: MagneQuest/Peerless Forum, What was your reflected load impedance? (0.00)
Posted by VoltSecond on 2005-11-14, 21:08:35 (68.3.241.102)
What was your reflected load impedance? There is more going on in these transformers than elliptic load lines. It sounds like you had some fun. Play safe and play longer! Don't be an "OUCH!" casualty .......
446: MagneQuest/Peerless Forum, Re: favorite knobs? (0.00)
Posted by VoltSecond on 2005-11-12, 15:21:37 (68.3.241.102)
Three polite knob sources I found. http://www.okwenclosures.com/products/okw/tuning-knobs.htm http://www.unisource-tech.com/Products_-_Unisource_Technolog/Components/Knobs/knobs.html Play safe and pl .......
447: MagneQuest/Peerless Forum, I never tackled those questions before. PJ will have a better idea. (0.00)
Posted by VoltSecond on 2005-11-10, 11:22:02 (68.3.241.102)
I never tackled those questions before. PJ will have a better idea. Here's a guess. Sensitivity to inductance: Reference: Goertz Air Coils claim +/- 2.5% On a first order crossover, 5% gives 0.215 dB .......
448: MagneQuest/Peerless Forum, The iron is only part of the equation, but that is a cool market idea. (0.00)
Posted by VoltSecond on 2005-11-09, 18:43:42 (68.3.241.102)
The iron is only part of the equation, but that is a cool market idea. Imagine crossover coils on low nickel! Target 10 to 20W maximum output power (845 output tube levels). Possibly pull a few taps i .......
449: Bottlehead Forum, I doubt that many headphones follow the 120 ohm standard. (0.00)
Posted by VoltSecond on 2005-11-05, 18:46:17 (68.3.241.102)
I doubt that many headphones follow the 120 ohm standard. They are worse than 8 ohm speakers being 8 ohms. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure .......
450: Bottlehead Forum, Buy one and try it. (0.00)
Posted by VoltSecond on 2005-10-29, 21:49:59 (68.3.241.102)
Buy one and try it. If you don't hear a change or feel a vibration in the disk, return it. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) befor .......
451: Bottlehead Forum, SPG will be the best, ground lug on the pot is good enough. (0.00)
Posted by VoltSecond on 2005-10-29, 21:46:15 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
452: Bottlehead Forum, I wouldn't call it demagnetizing. It is more like induction heating. (0.00)
Posted by VoltSecond on 2005-10-28, 20:01:27 (68.3.241.102)
I wouldn't call it demagnetizing, What it does is more like induction heating. I didn't believe it worked either until I tried it. This actually gives me an idea. Burn a CD with the same reference tra .......
453: Bottlehead Forum, Bulk Tape Eraser (0.00)
Posted by VoltSecond on 2005-10-27, 20:33:22 (68.3.241.102)
I learned some time ago that not all "snake oil" is bull shit. Often the explanation of how it works is faulty, not the end result. Jitter causing bad sound in CDs was caught by the golden ears long b .......
454: Bottlehead Forum, Name: Sound Impulse (0.00)
Posted by VoltSecond on 2005-10-26, 18:39:32 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
455: Bottlehead Forum, You're Welcome (nt) (0.00)
Posted by VoltSecond on 2005-10-25, 23:19:21 (68.3.241.102)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
456: Tweakers' Asylum, You can make it a little safer (0.00)
Posted by VoltSecond on 2005-10-22, 22:03:21 (68.3.241.102)
This response falls under the dreaded "Just say no, but if you don't say no, at least use some protection" type lecture. You can make it a little safer with a faster discharge, but the circuit would s .......
457: Tweakers' Asylum, I'd keep that circuit away from the wife, kids and the dogs too. (0.00)
Posted by VoltSecond on 2005-10-22, 21:52:18 (68.3.241.102)
If the Asylum claims copyright on the postings, will that make them liable for injuries? ;-] Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) bef .......
458: MagneQuest/Peerless Forum, MQA-18 (0.00)
Posted by VoltSecond on 2005-10-21, 20:54:22 (68.3.241.102)
If the DCR is resonably low, this could make a good headphone transformer. 7) MQA-18 small signal PP output trans. 20K CT primary secondary impedances of 50, 125, 200 CT, 250, 330, and 500 CT. MOL of .......
459: MagneQuest/Peerless Forum, Bottlehead Paramour. (0.00)
Posted by VoltSecond on 2005-10-19, 22:29:15 (68.3.241.102)
A frequency sweep or square wave test will show a resonance problem. Look at the waveform between the seried winding for execessive ringing. A series RC across one of the series windings will damp it. .......
460: Bottlehead Forum, That will make an attenuated standard volume control (0.00)
Posted by VoltSecond on 2005-10-19, 21:48:48 (68.3.241.102)
That will make an attenuated standard volume control. When you want to go shunt, jumper the wipe to the "right" tap. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it an .......
461: Bottlehead Forum, I never did find a good shorting switch. (0.00)
Posted by VoltSecond on 2005-10-19, 21:47:26 (68.3.241.102)
I never did find a good 12 position shorting switch. Silver plate on coin silver was what I was looking for. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measur .......
462: Bottlehead Forum, Re: Voltsecond - Shunt Mode Easy Way (0.00)
Posted by VoltSecond on 2005-10-19, 18:58:06 (68.3.241.102)
Wire your pot in shunt mode using the 75k. This would be installing R7 in the picture above. After the 75K is installed, you should be able to measure 75K across the 75K with the volume control at max .......
463: MagneQuest/Peerless Forum, It should work to make a 9K to 10 ohm. (0.00)
Posted by VoltSecond on 2005-10-18, 18:25:33 (68.3.241.102)
You'll risk a resonance between the transformers, but those can be damped. I'd rather have one set of windings in series and the other in parallel to force the balance. Play safe and play longer! Don .......
464: MagneQuest/Peerless Forum, Re: calculate insertion loss in db (0.00)
Posted by VoltSecond on 2005-10-17, 22:37:14 (68.3.241.102)
Midband insertion loss calculation Loss in dB = - 20 * log (Reflected load/(reflected load + DCR pri + DCRsec * Rpri/Rsec)) 5000 to 8 ohm 200 ohm DCR primary 0.32 ohm DCR secondary Loss in dB = -20 * .......
465: MagneQuest/Peerless Forum, The iron probably sounded good because (0.00)
Posted by VoltSecond on 2005-10-17, 21:41:33 (68.3.241.102)
The iron probably sounded good because the inductance was high and the ac swing was low. Interleaved iron won't have the best inductive linearity with drive. High inductance masks the nonlinearity. Pl .......
466: MagneQuest/Peerless Forum, Interleaved transformers still have a small airgap (0.00)
Posted by VoltSecond on 2005-10-17, 21:37:59 (68.3.241.102)
Note: Interleaved transformers still have a small airgap and the iron itself can support a little DC. Knowing E*dT = L*dI we can approximate the dc current capability. L will be the DC perm inductance .......
467: Bottlehead Forum, Try a 9V battery. (0.00)
Posted by VoltSecond on 2005-10-10, 13:28:03 (68.3.241.102)
With the power off and unplugged: Try a 9V Battery on your B+. I've the Foreplay 1 so I can't call out terminal numbers. The - side goes to signal ground and the + side to B+ of the cathode follower. .......
468: MagneQuest/Peerless Forum, Start here (0.00)
Posted by VoltSecond on 2005-10-07, 22:44:55 (68.3.241.102)
Start at the link below. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids thei .......
469: MagneQuest/Peerless Forum, A Puzzler (0.00)
Posted by VoltSecond on 2005-09-27, 21:13:48 (68.231.117.172)
A puzzler. The last time I saw something like that, one of the wires in the cable was broken. . . Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twic .......
470: Bottlehead Forum, Your idea will work. (0.00)
Posted by VoltSecond on 2005-09-27, 21:05:37 (68.231.117.172)
The sweet whispers is a standard stepped attenuator. Your idea will work. Remember to use high quality parts. Possibly another stepped resistor. Play safe and play longer! Don't be an "OUCH!" casualty .......
471: Bottlehead Forum, MilliVolt (0.00)
Posted by VoltSecond on 2005-09-27, 20:59:43 (68.231.117.172)
I became a a dad a short time ago. Most of my free time goes to blowing raspberries on MilliVolt's belly. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure i .......
472: Bottlehead Forum, Re: Foreplay Balance control. How do I do it? (0.00)
Posted by VoltSecond on 2005-09-26, 21:27:49 (68.231.117.172)
Another way to do it. Using the center picture, run the output to the top of your volume control. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twic .......
473: MagneQuest/Peerless Forum, CT hookups that usually work well (0.00)
Posted by VoltSecond on 2005-09-26, 21:12:11 (68.231.117.172)
CT hookups that usually work well (based on minimal noise pick up): 1. Attaching the secondary CT to ground through a 1 meg resistor can help with intermittent noise bursts that can occur when a float .......
474: MagneQuest/Peerless Forum, What influences phase shift at higher frequencies? (0.00)
Posted by VoltSecond on 2005-09-22, 22:31:05 (68.231.117.172)
The 10 kHz transformer question: What influences phase shift at higher frequencies? I know where to start with this question, but I don't know where or how to get to the end answering it. The short an .......
475: MagneQuest/Peerless Forum, Rubber flat washers (0.00)
Posted by VoltSecond on 2005-09-18, 13:08:54 (68.231.117.172)
Rubber flat washers between the transformer and chassis can help too. Ace Hardware has a nice selection. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it .......
476: Bottlehead Forum, You can also use 10g on a 15A breaker. (0.00)
Posted by VoltSecond on 2005-09-18, 13:06:36 (68.231.117.172)
You can also use 10g or 12g on a 15A breaker. Heavier wire on a smaller than standard breaker is often used for longer wire runs, wire runs where you want a lower IR drop and wires used in elevated te .......
477: Bottlehead Forum, My guess (0.00)
Posted by VoltSecond on 2005-09-18, 11:50:15 (68.231.117.172)
My guess is the increased capacitance of the Schottkies has lowered the ringing frequency of the HV secondary of the transformer so that more transformer electrical noise is now audible. Several thing .......
478: Bottlehead Forum, Re: C4S voltage drop and operating limits (0.00)
Posted by VoltSecond on 2005-09-14, 20:46:33 (68.231.117.172)
The C4S will work with as little as 3V across it, but works better with more volts across it. If you are B+ limited and want as much voltage swing as you can get, you want to bias the tube at [B+ low .......
479: MagneQuest/Peerless Forum, Re: thanks VS and Thorsten for your responses.... (0.00)
Posted by VoltSecond on 2005-09-07, 21:03:32 (68.231.117.172)
MilliVolt is doing great. She doesn't give me much time for soldering. She also likes to yank on any cord or wire she finds. She really like to shread books and magazines. Play safe and play longer! D .......
480: MagneQuest/Peerless Forum, It also could be a high frequency oscillation. (0.00)
Posted by VoltSecond on 2005-09-06, 19:13:32 (68.231.117.172)
Idea #1. The Foreplay has about a 1K output impedance. I don't remember the FM3s output impedance. Try a 1K across the RCA input to see if the problem goes away. If it works, increase it until the pro .......
481: Bottlehead Forum, If the SW is wired shunt mode (0.00)
Posted by VoltSecond on 2005-07-08, 21:00:12 (68.231.117.172)
If the SW is wired shunt mode, the 100K doesn't help with the poppint. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .......
482: Bottlehead Forum, Re: Attenuation with L-pad (0.00)
Posted by VoltSecond on 2005-07-07, 19:25:39 (68.231.117.172)
100K, 11.1K feeding 100K is 20 dB attenuation 100K, 11.1k feeding 50K is 21.6 dB attenuation. If the pot material and quality stayed the same, the sound should be the same, you'll just have to move th .......
483: Bottlehead Forum, Ditto (nt) (0.00)
Posted by VoltSecond on 2005-07-06, 18:55:36 (68.231.117.172)
. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it, discharge it and measure it (twice) before you touch it. . . .Oh!. . .Remember: Modifying things voids their warrantee. ::: TOPIC: .......
484: Bottlehead Forum, Re: Top Plate Vibration Damping (0.00)
Posted by VoltSecond on 2005-07-01, 19:27:10 (68.231.117.172)
I was told that automotive window putty works the best (I haven't tried it yet), but stains everything it touches. The automotive window putty is supposed to take the longest time in drying up and har .......
485: Bottlehead Forum, They take a while to break in. (0.00)
Posted by VoltSecond on 2005-06-24, 22:12:13 (68.231.117.172)
They take a while to break in. I like the sound of mine with a computer arm rest placed under the front edge to tilt them back a bit. Play safe and play longer! Don't be an "OUCH!" casualty. Unplug it .......
486: Bottlehead Forum, Get copies of the X-rays to bring with you when you fly. (0.00)
Posted by VoltSecond on 2005-06-20, 19:48:21 (68.231.117.172)
Mrs. Volt's old boss gave herself a spiral fracture skiing. They had to leave the metal pins and screws in after she healed. Now she sometimes has a hard time convincing security she doesn't have a we .......
487: MagneQuest/Peerless Forum, Have you tried Uncle Ned's driver cards? (0.00)
Posted by VoltSecond on 2005-06-13, 22:10:26 (68.231.117.172)
I put them in my MK IIIs and was impressed. I haven't gotten around to tweaking them up further (to many ideas and too little time.) Ned's mods may hold you for a while. Play safe and play longer! Do .......
488: Bottlehead Forum, Subwoofers (0.00)
Posted by VoltSecond on 2005-06-01, 20:54:40 (68.231.117.172)
Can you run the sub off the output of the power amp? REL recommends running this way because the sub will blend in better with how the main speakers are interacting with the power amp. Play safe and p .......
489: General Asylum, Re: I have a lot of two prong equipment. (0.00)
Posted by VoltSecond on 2005-05-26, 19:25:42 (68.231.117.172)
I usually use a 1 megohm DVM. I've seen up to 7 mA of chassis leakage current. A dangerous amount. I seem to remember the chassis voltage was 60V in that case. The Thevenin equivalent would be -j8.5K .......
490: General Asylum, I have a lot of two prong equipment. (0.00)
Posted by VoltSecond on 2005-05-25, 22:03:00 (68.231.117.172)
I've seen nearly 80V ac drop to 30V ac on the chassis by swapping the polarity of the transformer leads. 100 feet of romex from the outlet to the breaker box at 10 amps inducing 200 mV on the safety g .......
491: General Asylum, Have fun and share what you learn. (0.00)
Posted by VoltSecond on 2005-05-24, 22:28:28 (68.231.117.172)
Electrostatically shield your test wires by wrapping copper foil covered with tape around them so they are 100% covered, but the copper foil doesn't make a shorted turn. Ground the copper foil to elim .......
492: General Asylum, Just say no to cheater plugs. (0.00)
Posted by VoltSecond on 2005-05-23, 23:30:37 (68.231.117.172)
I agree. Just say no to cheater plugs. Fix the wiring inside the electronics after you figure out how it should be wired instead of using a cheater plug. I also agree that the fuse and switch go on th .......
493: General Asylum, Probably before then too. (0.00)
Posted by VoltSecond on 2005-05-22, 21:14:27 (68.231.117.172)
The effects of "winding polarity" on capacitive coupling between windings and winding to core is discussed in some very old transformer books. However, they use non-audio terms (effective capacitance, .......
494: General Asylum, I've found the "polarity" of transformers to be a capacitance issue. (0.00)
Posted by VoltSecond on 2005-05-21, 18:51:35 (68.231.117.172)
I've found the "polarity" of transformers to be an issue because of parasitic capacitances. The physical location and mounting rotation of the transformer is usually an issue because of inductive coup .......
495: Bottlehead Forum, Use a fuse (0.00)
Posted by VoltSecond on 2005-05-17, 14:57:33 (68.231.117.172)
I'd wire your T-amp with #22 to the battery and put a 2 amp fuse in the hot lead close to the battery pack. Batteries don't deliver current as fast as the T-amp will want it. Add a bank of aluminum ca .......
496: Bottlehead Forum, That depends on the attenuation and input resistance you want. (0.00)
Posted by VoltSecond on 2005-05-16, 19:02:55 (68.231.117.172)
Knowing solid state sources will drive a 10K load and most tube sources can handle a 50K load, we can pick a minimum input impedance for the attenuator. For a 100K pot, you could use a 10K in series a .......
497: Bottlehead Forum, More capacitance (0.00)
Posted by VoltSecond on 2005-05-08, 15:02:14 (68.231.117.172)
More output capacitance gives the preamp a better chance of rejecting hum and noise picked up by the cabling. The point of diminishing returns is when 1/(2*pi*F*C) = output impedance of the tube at 60 .......
498: Bottlehead Forum, Re: AM/FM Tuner for use with Foreplay (0.00)
Posted by VoltSecond on 2005-05-06, 18:38:36 (68.231.117.172)
You can mod Kenwood 7300/ 7500 fairly easy. I picked up a 7500 on ebay that had undisclosed problems. The 7300 from Ebay was a winner. I haven't had time to fix the 7500 yet. I think an RF stage is bu .......
499: Bottlehead Forum, Cool tool at Costco (0.00)
Posted by VoltSecond on 2005-04-26, 22:07:53 (68.231.117.172)
Costco has an AllTrade infrared thermometer for $69. What this tool does for you is let you safely know how hot something is while it still has voltage on it. This means no more "OUCH"es from shocks o .......
500: MagneQuest/Peerless Forum, Re: Strange/Interesting Idea (0.00)
Posted by VoltSecond on 2005-04-26, 21:56:00 (68.231.117.172)
Q: The fun part here is, what are the parameters that make a filament isolation transformer good for audio? 1. Strangely enough, poor regulation may be a good thing in a filament transformer. If the f .......
Found total of 500 records, Query: , Author: VoltSecond in All Forums, Time: 2 sec.