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1: Tube DIY Asylum, RE: Alodine / Iridite Chromate Conversion (0.00)
Posted by Maxamillion on 2021-12-29, 16:21:42 (74.105.175.202)
Alodine is toxic and potentially carcinogenic, so I wouldn't soak a panel in it. That said, I use an Alodine pen to treat aluminum chassis to ensure electrical connectivity among all the panels. Basic .......
2: Tube DIY Asylum, RE: Grid Choke (0.00)
Posted by Maxamillion on 2021-07-26, 02:43:42 (172.58.236.216)
Very nice work! Yes, the 01A is special. I originally had the 26 in there, but the thoriated tungsten filament of the 01A has a bit more of everything good to my ears. .......
3: Tube DIY Asylum, RE: Grid Choke (0.00)
Posted by Maxamillion on 2021-07-25, 18:27:50 (172.58.236.162)
Here's the preamp power supply, contained in a separate chassis. B+, filaments, DAC and TAP-X controls. All choke-input supplies. .......
4: Tube DIY Asylum, RE: Grid Choke (0.00)
Posted by Maxamillion on 2021-07-25, 18:23:47 (172.58.236.162)
I use a silver-wound, nickle-core Slagle AVC, but it's part of the Bent Audio TAP-X passive preamp that I incorporated into the preamp. Basically I wrapped the TAP-X around an active tube linestage .......
5: Tube DIY Asylum, RE: Grid Choke (0.00)
Posted by Maxamillion on 2021-07-25, 17:20:24 (172.58.239.60)
It's not a step-up, it's actually a 2:1 (4:2 wiring) step-down of the input signal to keep the 01A output (8x Vinput) from overloading the AVC on the preamp output. It also inverts the signal phase .......
6: Tube DIY Asylum, RE: Grid Choke (0.00)
Posted by Maxamillion on 2021-07-25, 15:07:38 (172.58.236.6)
Don't need it on the 833, it's direct-coupled from a mosfet "gyrator" with a separate 400V LCLC power supply capable of applying any amount of grid current it needs (and then some!). A real choke befo .......
7: Tube DIY Asylum, Grid Choke (0.00)
Posted by Maxamillion on 2021-07-25, 09:07:23 (172.58.239.37)
A grid choke is a nice, albeit expensive option. I use a Lundahl grid choke in my 833 amps' input stage. 5k DC resistance but very high AC impedance means a very stable grid. Sounds great! ::: TOP .......
8: Amp/Preamp Asylum, RE: Should have said the filaments (0.00)
Posted by Maxamillion on 2021-07-20, 18:45:28 (172.58.236.116)
That's mild. I have been enjoying my DIY 833C SET monoblocks running 2.3kV on the plate for 7 years now. 200W per channel from one tube. The 833C filament alone consumes 100W (10V at 10A). The plat .......
9: Tube DIY Asylum, RE: Fixed Cathode Bias (0.00)
Posted by Maxamillion on 2021-07-20, 16:28:59 (172.58.236.99)
Look into my glow...you are getting itchy solder fingers...you know you want it... .......
10: Tube DIY Asylum, RE: Fixed Cathode Bias (0.00)
Posted by Maxamillion on 2021-07-19, 18:21:56 (172.58.238.181)
For my 833C amps I needed something pretty beefy to handle the voltage and current plus grid current, so I stuck a K&K Audio HV shunt regulator in the 833C cathode. I replaced the stock pass MOSFET .......
11: Tube DIY Asylum, RE: Finally Complete - 304tl (0.00)
Posted by Maxamillion on 2020-06-02, 13:46:51 (172.58.220.67)
Very nice job! Love the big transmitters. .......
12: Amp/Preamp Asylum, I'd have to say the monos I built (0.00)
Posted by Maxamillion on 2020-05-21, 14:57:50 (172.58.239.105)
6E5P driver, 833C power tube, 200WPC DHT SET. No problem driving big Infinity RSIIb speakers with SET finesse. .......
13: Tube DIY Asylum, RE: You're getting there... (0.00)
Posted by Maxamillion on 2019-01-27, 10:37:18 (172.56.36.38)
About 200WPC IN A2. 40WPC in A1. .......
14: Tube DIY Asylum, You're getting there... (0.00)
Posted by Maxamillion on 2019-01-27, 07:51:02 (172.56.22.85)
It's not crazy until you break the 2000V barrier! 2300V here. Love the look of the 304TL, though! .......
15: Tube DIY Asylum, Don't Overwork It. (0.00)
Posted by Maxamillion on 2018-11-30, 15:35:23 (172.58.233.136)
I had one of those burn out on me doing some medium-level grinding. Definitely not as durable as the corded model. .......
16: Tube DIY Asylum, I've had great luck (0.00)
Posted by Maxamillion on 2018-11-23, 17:39:49 (172.58.232.111)
At hamfests and antique radio shows. I've picked up 26s for $5-10 each, with excellent test results. I prefer the balloon type and those are a little more scarce than the ST, but still around. e-bay i .......
17: SET Asylum, RE: Speaking of KVs...building a HV power supply. (0.00)
Posted by Maxamillion on 2018-10-01, 04:31:02 (172.58.232.138)
I see you're in Kentucky...drop me a line if you're ever up in the central NJ area and maybe we can arrange for you to hear the RSIIbs with DHTs! I love to demo my system to other tube lovers. ::: .......
18: SET Asylum, Well, you could read my build thread (0.00)
Posted by Maxamillion on 2018-09-29, 07:23:07 (172.56.37.249)
For my 833C amps I use a 2.3kV supply. Lots of details about safety, insulation, arc prevention, etc. They've been running safely for several years now, sound great, and they'll drive just about any s .......
19: SET Asylum, And if you don't mind wrangling kV's (0.00)
Posted by Maxamillion on 2018-09-28, 15:55:22 (172.56.37.104)
You can even get 200WPC out of a single DHT. .......
20: Tube DIY Asylum, RE: Envy much! :^) nt. (0.00)
Posted by Maxamillion on 2018-07-21, 18:53:36 (172.58.184.83)
In any case, my point was that I had no problem stacking Cree SiC diodes, in a very high voltage power supply, despite the warnings to the contrary. .......
21: Tube DIY Asylum, RE: Used Series 1200V Crees in my 833C amp (2.3kV B+) (0.00)
Posted by Maxamillion on 2018-07-21, 18:46:12 (172.58.184.83)
No noise issues. The amps sound fantastic driving Infinity RSIIb speakers. Imagine being able to drive 83db speakers with an SET! .......
22: Tube DIY Asylum, Used Series 1200V Crees in my 833C amp (2.3kV B+) (0.00)
Posted by Maxamillion on 2018-07-21, 18:23:58 (172.58.184.83)
In a bridge. No resistors at all, (5) 1200V diodes and (5) 10nF 1250V caps per leg. It's been running for 5 years with no failures to date. See picture. .......
23: Tweakers' Asylum, RE: A Couple of Q's on the AA Speaker Filters (0.00)
Posted by Maxamillion on 2018-03-09, 12:34:25 (208.251.134.73)
It makes no difference which side of the circuit you put the resistor on. It would be fine to split the value in two and put 1/2 value on each side of the circuit. I don't see an advantage in putting .......
24: Tube DIY Asylum, There is a Third Option (0.00)
Posted by Maxamillion on 2018-01-03, 10:59:19 (4.16.91.186)
DHT SE and Panel Speakers together. You just need a couple KV of B+ .......
25: Tube DIY Asylum, RE: Umbilical Recommendation (0.00)
Posted by Maxamillion on 2017-12-31, 16:54:23 (74.105.78.32)
Speakons can handle much more than 300V. They don't rate them higher because they don't want professionals to use them for anything other than speakers, to prevent some roadie from plugging HT into a .......
26: Tube DIY Asylum, Speakons are my Go-to for Umbilicals (0.00)
Posted by Maxamillion on 2017-12-31, 16:42:24 (74.105.78.32)
Both HT and filaments. Positive locking and touchproof, too. Plus, the metal ones look pretty slick, and are very durable. Here's a pic of my 26 preamp/DAC and umbilical for reference. .......
27: Amp/Preamp Asylum, Toroid Autoformer (0.00)
Posted by Maxamillion on 2017-12-21, 06:22:47 (74.105.78.32)
Yup, that's what the Speltz Zero autoformer is. .......
28: SET Asylum, I'd go 833C SET (0.00)
Posted by Maxamillion on 2017-12-06, 15:38:15 (74.105.78.32)
But that's just me. Monolith output iron sounds incredible with this tube. No problem driving old current-hog 6-way 83dB speakers, either. .......
29: Tube DIY Asylum, Ultrasound and Hearing Damage (0.00)
Posted by Maxamillion on 2017-11-12, 13:12:57 (172.56.36.66)
Although Ultrasound cannot be heard by humans, at high decibels it can still cause direct damage to human ears. Ultrasound in excess of 120 decibels may cause Hearing damage. Exposure to 155 decibels .......
30: Tube DIY Asylum, RE: Question for DIYers (0.00)
Posted by Maxamillion on 2017-11-12, 03:43:42 (74.105.78.32)
It sounds fantastic, just how you'd imagine a 200wpc SET would sound. Also been very reliable in the 4 years since I've built it. It was a massive undertaking, however. .......
31: Tube DIY Asylum, RE: Question for DIYers (0.00)
Posted by Maxamillion on 2017-11-11, 18:22:20 (74.105.78.32)
Seven 450V caps in series have no problem with that voltage. Approximately 200WPC, running at 160mA. you can read all about the build at the link. .......
32: Tube DIY Asylum, RE: Question for DIYers (0.00)
Posted by Maxamillion on 2017-11-11, 17:39:47 (74.105.78.32)
Well, I haven't burned my house down with my 833C amps that run at 2300V, but I also don't leave them on and go out for a walk, either. .......
33: SET Asylum, RE: What, just a single 833? :-) (nt) (0.00)
Posted by Maxamillion on 2017-05-08, 14:10:35 (98.109.217.121)
Yup, at plate voltage of 2.3kV, idle current of 160mA. Monolith Magnetics amorphous core OPT. .......
34: SET Asylum, I drive 83dB Speakers that dip to 1.6ohms with an SET (0.00)
Posted by Maxamillion on 2017-05-07, 10:40:17 (172.56.37.184)
The system sounds magnificent. If you're anywhere near NJ you could stop by and hear for yourself. Of course these are unique SETs that I built myself, so not commercially available. .......
35: Tube DIY Asylum, RE: 6E5P (0.00)
Posted by Maxamillion on 2016-12-26, 16:36:02 (173.70.90.126)
That's a Lundahl grid choke. Just a substitute for the typical grid resistor. It gives a low impedance for DC (5K) together with a very high impedance for the music signal. It's not critical to the op .......
36: Tube DIY Asylum, 6E5P (0.00)
Posted by Maxamillion on 2016-12-26, 15:52:25 (173.70.90.126)
Here's the datasheet, Paul. Excellent driver tube. .......
37: SET Asylum, Or you can build an SET with sheer power... (0.00)
Posted by Maxamillion on 2016-09-20, 07:26:50 (172.56.23.252)
Even a DHT one. Just takes a couple 833s, a couple Monolith OPTs and the willingness to work with 2kV. .......
38: Tweakers' Asylum, RE: Perhaps I figured it out... (0.00)
Posted by Maxamillion on 2016-03-26, 09:48:03 (107.77.70.82)
Yes, that is why. Shunt caps shunt more efficiently as the frequency is increased. Series inductors are also more effective at blocking higher frequencies. Also, a higher frequency is easier on the ir .......
39: Tweakers' Asylum, RE: No Bypass at all sounds best to me. (0.00)
Posted by Maxamillion on 2016-03-26, 09:37:08 (107.77.70.82)
The cap should not rattle. Could be dried out. .......
40: Tube DIY Asylum, I Use Two of the P5s in my System (0.00)
Posted by Maxamillion on 2016-03-12, 09:29:11 (107.77.70.128)
One for each 833 monoblock, with the front end components distributed between the two so that each is at about 80% of capacity. Dedicated line powering them is 8 gauge Romex. .......
41: Tube DIY Asylum, From their Website (0.00)
Posted by Maxamillion on 2016-03-11, 19:12:11 (108.35.216.100)
It has a Class A/B output stage, but they have some unique digital electronics that allow it to operate much more efficiently than the old P300 and P500 type units, they claim. Something about trackin .......
42: Tube DIY Asylum, RE: PS AUDIO P3, P5 or P10 (0.00)
Posted by Maxamillion on 2016-03-08, 11:46:11 (216.0.238.6)
Never said it was cheap. Just said that it works well. .......
43: Tube DIY Asylum, Nah, Class A/B (0.00)
Posted by Maxamillion on 2016-03-08, 09:34:22 (216.0.238.6)
Basically a big SS Class A/B power amplifier tuned to line frequency. Takes the wall AC, converts it to DC, filters it, then modulates it at 60Hz. .......
44: Tube DIY Asylum, PS AUDIO P3, P5 or P10 (0.00)
Posted by Maxamillion on 2016-03-06, 09:08:21 (107.77.106.32)
All are AC voltage regenerators that also allow you to dial in whatever voltage you need. I currently use a P5 to feed each of my 833 amps at about 112V from a 123V line. Keeps transformers quiet, hea .......
45: Tweakers' Asylum, No Bypass at all sounds best to me. (0.00)
Posted by Maxamillion on 2016-02-13, 06:45:10 (107.77.76.81)
Any bypass I tried made the sound too bright on my system. Just the battery and the 47,000uF sounded best to me. I've found the positive impact to be in the areas of mid bass fullness and bass dynamic .......
46: Speaker Asylum, Boston Acoustics A-400 (0.00)
Posted by Maxamillion on 2016-02-06, 17:49:24 (108.35.216.100)
Excellent, reasonably-priced speaker, designed to go against the front wall. Had a pair and sold them but man they sounded good! .......
47: Tweakers' Asylum, Bypasses sound too tilted up IMO (0.00)
Posted by Maxamillion on 2016-01-18, 09:46:32 (216.0.238.6)
So I removed them. Just a 47,000uF cap and a 9V battery works best in my system, wwhich already has plenty of high end. I notice a fuller bass/lower midrange and a little more dynamics, but no effect .......
48: Tube DIY Asylum, RE: Very Nice Job! (0.00)
Posted by Maxamillion on 2016-01-15, 10:23:10 (216.0.238.6)
I consider it a compliment - thanks! The filament supply outboarding is mainly to satisfy my OCD. I have another 10"x13"x4.25" Landfall chassis already, and all of the parts I need sitting in my basem .......
49: Tube DIY Asylum, Very Nice Job! (0.00)
Posted by Maxamillion on 2016-01-15, 10:04:33 (216.0.238.6)
Black Landfall chassis, Simpson milliammeter on the front panel, blue lit HV pushbutton...I like your taste! ;-) Seriously, I hope it sounds as good as it looks! .......
50: Tweakers' Asylum, RE: Something new (0.00)
Posted by Maxamillion on 2015-12-16, 18:22:43 (108.35.216.100)
Interesting. Same thing I hear - fuller mid-bass and more impactful bass. Now if we can only figure out why... .......
51: Tweakers' Asylum, RE: I perceive that you know more about electricity than I do. (0.00)
Posted by Maxamillion on 2015-12-15, 08:17:42 (166.137.252.26)
I'm trying to stimulate discussion of the various possibilities, not trying to have it both ways. I haven't decided which if any of these I believe. Is the BGT interacting with/charging hidden parasi .......
52: Tweakers' Asylum, RE: Question (0.00)
Posted by Maxamillion on 2015-12-14, 16:21:10 (166.137.252.26)
Where is the complete circuit when charges move from a Vandegraff generator to a person on an insulated platform? The other thing to think about are all the "unseen circuits" in any system, the ones t .......
53: Tweakers' Asylum, It's actually not in equilibrium at all (0.00)
Posted by Maxamillion on 2015-12-14, 14:11:04 (166.137.252.26)
Rather at best it achieves steady state conditions, as there is always a leakage current flowing. Steady state is only steady until the system changes in some way. Connecting a fluctuating audio groun .......
54: Tweakers' Asylum, RE: Question (0.00)
Posted by Maxamillion on 2015-12-14, 13:30:25 (166.137.252.26)
Electrons are charge carriers, and the flow of charge is current. Having more charge carriers available to respond to current demands certainly seems like it would help with dynamics, no? .......
55: Tweakers' Asylum, RE: Farraday Cage? (0.00)
Posted by Maxamillion on 2015-12-14, 13:25:38 (166.137.252.26)
A fluctuating AC voltage connected to the negative plate is certainly a reason for equilibrium to be disturbed. Equilibrium is simply a mental construct to represent the time-averaged behavior; in rea .......
56: Tweakers' Asylum, RE: Farraday Cage? (0.00)
Posted by Maxamillion on 2015-12-14, 04:47:29 (166.137.252.26)
Good points and I believe I did mention the effect of the positive plate in pulling the charge back, somewhere in this thread. Perhaps, though, just disturbing the equilibrium temporarily is enough. R .......
57: Tweakers' Asylum, RE: Farraday Cage? (0.00)
Posted by Maxamillion on 2015-12-13, 19:05:35 (108.35.216.100)
A normal grounded chassis is already a Faraday cage if it completely encloses the electronics, is thicker then the skin depth of the RF and doesn't have large openings relative to the RF frequency. No .......
58: Tweakers' Asylum, More info (0.00)
Posted by Maxamillion on 2015-12-13, 18:27:53 (108.35.216.100)
According to the link here, when the negative of a charged cap is connected to ground, some charge is expected to redistribute itself into the ground, since attaching the ground changes the system (it .......
59: Tweakers' Asylum, RE: You asked for it... (0.00)
Posted by Maxamillion on 2015-12-13, 05:48:51 (166.137.252.26)
That's a possibility, and one I thought of way back when I first read about this. Actually, that's why it took me this long to try it. I can't however reconcile RF pickup with the bass impact and dyna .......
60: Tweakers' Asylum, But What about the Grounded Chassis? (0.00)
Posted by Maxamillion on 2015-12-13, 04:11:01 (166.137.252.26)
Having the chassis grounded, as most equipment does, would seem to pose a challenge to the electrostatic model here, since excess charge should continue to spread out as long as there is a conductive .......
61: Tweakers' Asylum, The Physics of The Battery Ground Tweak (0.00)
Posted by Maxamillion on 2015-12-12, 15:44:53 (166.137.252.26)
OK, so everyone seems to be at a loss to explain how the BGT does what it does because there is no complete circuit formed. However, electrostatics may provide an explanation. An entity with a large e .......
62: General Asylum, Please Unplug Me when this happens... (0.00)
Posted by Maxamillion on 2015-12-07, 18:03:08 (108.35.216.100)
Heaven or Hell. You decide. .......
63: Tweakers' Asylum, Guilford of Maine is a Good Place to Start (0.00)
Posted by Maxamillion on 2015-12-05, 17:32:33 (108.35.216.100)
See link. .......
64: Tweakers' Asylum, Mudorf Supreme are very good (0.00)
Posted by Maxamillion on 2015-11-30, 06:38:31 (216.0.238.6)
I use them in my speakers. A bypass with .01uF Audiocap Theta is my preferred implementation, it seems to smooth them out a little bit. My speakers use 2uF and 3uF caps on the tweeters (not standard v .......
65: Tweakers' Asylum, Agreed, but in power supplies (0.00)
Posted by Maxamillion on 2015-11-29, 15:40:14 (108.35.216.100)
I've had very good results with them as filter caps instead of electrolytics. As a tweeter cap they are harsh, though. The Tempoelectric cap review finds the same, good in PS but not so good in x-over .......
66: Tweakers' Asylum, Ditched the Bypass Cap...Better Balance (0.00)
Posted by Maxamillion on 2015-11-29, 04:46:20 (216.0.238.6)
After a few days of listening thanks to the long holiday weekend, I noticed a brightness on some songs that had not been present previously. I thought perhaps the PP bypass cap might be to blame, so I .......
67: Tweakers' Asylum, Listening impressions (0.00)
Posted by Maxamillion on 2015-11-27, 04:51:14 (108.35.216.100)
After two days of listening, this is what I hear: Punchier, deeper bass with the BGT. Perhaps a little more bass detail. This is the most obvious difference. Slightly cleaner overall presentation, but .......
68: Tweakers' Asylum, Here's what I Ended Up Doing (pics) (0.00)
Posted by Maxamillion on 2015-11-25, 20:27:51 (108.35.216.100)
I built a BGT in a project box with a 47,000uF, 16V Panasonic T-HA main cap and a 4.7uF Solen PP bypass cap, and an Energizer 9V Alkaline battery. I added an internal 9V battery tray to make battery c .......
69: Tweakers' Asylum, That's .047F, same as 47,000uF (0.00)
Posted by Maxamillion on 2015-11-18, 10:23:42 (100.1.54.192)
So that would be reflective of what seems to be the most popular configuration. However, if you look closely at the graph it doesn't actually approach zero current until 300msec or so. At 80msec it's .......
70: Tweakers' Asylum, RE: A Discharged Cap is a Short Circuit to DC (0.00)
Posted by Maxamillion on 2015-11-18, 08:27:05 (100.1.54.192)
Yes, I thought about a pre-charge using a resistor as an alternative to wiring it permanently into the system, or perhaps a switch so that one could switch the resistor into the circuit for charging t .......
71: Tweakers' Asylum, Here's a Startup Simulation in LTSpice (0.00)
Posted by Maxamillion on 2015-11-17, 18:32:12 (100.1.54.192)
Note the transient current flow upon startup (connection of the 9V battery). I assigned a 1 ohm resistance to the battery and .02 ohm to the cap. In about 1/3 second the current is approaching zero, b .......
72: Tweakers' Asylum, A Discharged Cap is a Short Circuit to DC (0.00)
Posted by Maxamillion on 2015-11-17, 17:53:36 (100.1.54.192)
until it charges up, then it becomes a near infinite impedance to DC. The current required to charge an empty cap is called "inrush current". Think about it, AC can pass through a cap because the cap .......
73: Tweakers' Asylum, I just looked up the internal impedance (0.00)
Posted by Maxamillion on 2015-11-17, 12:41:03 (216.0.238.6)
of an alkaline 9V battery and it's typically 1-2ohms, so maybe this isn't a big issue after all. At 1ohm, with a .02ohm cap the max current would be 9/1.02 = 8.8A. Still, I might want another ohm or t .......
74: Tweakers' Asylum, I meant for the initial chargeup of the cap (0.00)
Posted by Maxamillion on 2015-11-17, 12:31:16 (216.0.238.6)
When a discharged cap is connected to a battery it does form a complete circuit, and it will appear as a short circuit to the battery until it charges up. Current of hundreds of amps can flow for a sh .......
75: Tweakers' Asylum, Anyone Use a Series Resistor in their BGT to Limit Current? (0.00)
Posted by Maxamillion on 2015-11-17, 08:42:58 (216.0.238.6)
Seems like it would be good practice to add a series resistor of a few ohms in the + leg of the BGT, between the battery and cap, to limit current on first charging. A 47,000uF cap will pull a LOT of .......
76: Tweakers' Asylum, Just Tried this... (0.00)
Posted by Maxamillion on 2015-11-15, 14:07:12 (107.77.70.78)
Went into the junk box, soldered up two 5600 and two 4700 Panasonic T-HA electrolytics, a 1uF Solen PP bypass and an Energizer 9V. Also soldered a clip lead to the negative of the battery so I could t .......
77: K&K Audio / Lundahl Transformers, RE: Mu Output CCCS (0.00)
Posted by Maxamillion on 2015-11-13, 20:27:26 (100.1.54.192)
On the Compact Cascode board, it turns out that the solder pad at the top of the Rset position (next to the R) is a perfect place to take off the mu output. I use that with excellent results in my 26 .......
78: Cable Asylum, Event ICs are Pure Silver, as are the S/PDIF (0.00)
Posted by Maxamillion on 2015-11-09, 05:10:18 (216.0.238.6)
According to the Zu Website. The Event speaker cables are some copper/silver combo. I don't use any speaker cables per se as I have my mono amps wired directly to the speaker crossovers with a hard-wi .......
79: Cable Asylum, Thinking about the Event S/PDIF MkII for my DAC (0.00)
Posted by Maxamillion on 2015-11-08, 12:24:24 (100.1.54.192)
Currently I'm using a $20 true 75ohm BNC cable from Digikey, on the theory that digital is less prone to cable effects. Sounds great now but with the 60-day return policy Zu has I figure why not try t .......
80: Cable Asylum, RE: Yes, Zenwave (Daves Cables) D4s... (0.00)
Posted by Maxamillion on 2015-11-07, 20:26:58 (100.1.54.192)
Hmmm...interesting. I'm happy with the Events, but the grass is always greener, as they say. .......
81: Cable Asylum, What Balanced ICs are you using? (0.00)
Posted by Maxamillion on 2015-11-07, 11:10:33 (107.77.70.23)
Did you go "up the food chain" to higher priced ICs? .......
82: Cable Asylum, Zu Event ICs - Anyone Else Using Them? (0.00)
Posted by Maxamillion on 2015-11-07, 05:46:20 (107.77.70.23)
I changed over from Zu Varial to Zu Event RCA IC throughout my system a year or so ago, and I have to say these are excellent cables! Exceedingly clean and clear, yet smoother than the Varials. Imagin .......
83: Amp/Preamp Asylum, RE: I believe it is true for you, but clearly not for everyone else...nt (0.00)
Posted by Maxamillion on 2015-11-06, 05:49:28 (216.0.238.6)
OK, Switzerland is a good excuse...:-) .......
84: Amp/Preamp Asylum, RE: I believe it is true for you, but clearly not for everyone else...nt (0.00)
Posted by Maxamillion on 2015-11-06, 05:24:53 (216.0.238.6)
"Max's monster might be the end all of amps...or not...until one hears it one cannot say for sure. It sure stands a good chance though of sounding awesome." Are you also too far from NJ to check it o .......
85: Amp/Preamp Asylum, RE: kV Voltages do wonderful things to an SET. (0.00)
Posted by Maxamillion on 2015-11-05, 14:09:11 (216.0.238.6)
Here are the OPT cores before potting, with a metric ruler and an ECC83 for scale: .......
86: Amp/Preamp Asylum, RE: Any of you near Central NJ? Stop by for a Listen! (0.00)
Posted by Maxamillion on 2015-11-05, 14:07:09 (100.1.54.192)
I can tell you that at full 200W output the bandwidth is 32Hz to 60kHz. I never need close to that output, though. The bass shakes the walls when I play Yello. Haven't measured the distortion mainly b .......
87: Amp/Preamp Asylum, RE: Any of you near Central NJ? Stop by for a Listen! (0.00)
Posted by Maxamillion on 2015-11-05, 13:59:58 (216.0.238.6)
You can always ask them. Drop Ward a line - he's a great guy and fellow DIY nut. .......
88: Amp/Preamp Asylum, Ultra-Efficient Speakers Aren't a Requirement (0.00)
Posted by Maxamillion on 2015-11-05, 13:57:23 (216.0.238.6)
If done right you can even power amp-eaters like the old Infinity speakers with an SET. These dip to 1.6 ohms impedance at one point in the FR! Here's mine in action for a local audio club get-togethe .......
89: Amp/Preamp Asylum, RE: Any of you near Central NJ? Stop by for a Listen! (0.00)
Posted by Maxamillion on 2015-11-04, 13:38:17 (216.0.238.6)
Too bad. I think you'd enjoy them. What specs would you like? They weigh 180 lbs each, have a 2.3kV B+ on the 833C at 160mA, are pure Class A1 up to 40W then Class A2 after that up to 200W. Completely .......
90: Amp/Preamp Asylum, kV Voltages do wonderful things to an SET. (0.00)
Posted by Maxamillion on 2015-11-04, 10:16:40 (216.0.238.6)
Slam and impact galore are a byproduct of 2.5kV power supplies, one per channel. 400J of energy storage per channel can really move a woofer! .......
91: Amp/Preamp Asylum, Any of you near Central NJ? Stop by for a Listen! (0.00)
Posted by Maxamillion on 2015-11-04, 10:11:28 (216.0.238.6)
The offer is open. PM me if you want to hear an SET that can do full-range as well as anything out there, be it solid state, class D, whatever. No need for a sub at all, while retaining the SET magic. .......
92: Amp/Preamp Asylum, RE: What amp is that? (0.00)
Posted by Maxamillion on 2015-11-04, 06:49:02 (216.0.238.6)
Built it myself. Here's a link to the build thread complete with schematics, measurements, etc. .......
93: Amp/Preamp Asylum, Owned the Gilmores, Heard the Merrills (0.00)
Posted by Maxamillion on 2015-11-03, 18:54:44 (100.1.54.192)
Neither sounded as good as my SET amps. The 3D imaging and clarity are orders of magnitude better with the SETs. And so is the bass, believe it or not. They just sound more real - by a lot! ::: TO .......
94: SET Asylum, I use Transformers IN my DIY DAC (0.00)
Posted by Maxamillion on 2015-10-21, 11:39:14 (107.77.85.117)
Signal from DAC goes into LL1676, then to 26 DHT output stage. Transformers block DC offset and filter DAC HF nasties. Never heard better... .......
95: Amp/Preamp Asylum, RE: I DON'T BELIEVE THAT (0.00)
Posted by Maxamillion on 2015-10-01, 19:09:59 (100.1.122.61)
Euphonic: adjective denoting or relating to euphony; pleasing to the ear God forbid - unless my music sounds UNPLEASING I'm not happy! Bleed eardrums, bleed! ----Feanor .......
96: Amp/Preamp Asylum, Perhaps you forgot feedback time errors make many cycles through the amp circuit (0.00)
Posted by Maxamillion on 2015-09-20, 07:50:57 (107.77.70.113)
"correcting" and re-correcting on each cycle. These newly-created errors eventually reach audio time scales and are heard as TIM distortion. Such errors are perfectly acceptable when using feedback th .......
97: Amp/Preamp Asylum, Especially ones that require time travel to work! (0.00)
Posted by Maxamillion on 2015-09-19, 11:06:01 (107.77.70.25)
In other words, those that use global negative feedback to "correct" events that have already passed. TIM, anyone? Especially bad when the output filter/transformer is in the loop. Honestly how could .......
98: Tube DIY Asylum, RE: You can have both SET immediacy and tons of power (0.00)
Posted by Maxamillion on 2015-09-17, 11:19:58 (107.77.70.36)
"I don't have your millions" Well, that makes two of us! Wish I could find the guy who has my millions, though... .......
99: Cable Asylum, RE: Cables to Add Warmth (0.00)
Posted by Maxamillion on 2015-09-17, 07:45:14 (107.77.70.36)
Funny you say that. I recently swapped out the Zu Event silver ICs from my pre to amps and replaced them with generic PVC insulated ICs (from Radio Shack, I think) I had laying around and noticed a HU .......
100: Tube DIY Asylum, You can have both SET immediacy and tons of power (0.00)
Posted by Maxamillion on 2015-09-16, 15:49:19 (166.137.252.51)
You just need to be willing to work with 2+ kV. The 833 is a DHT, too... http://www.diyaudio.com/forums/tubes-valves/232484-midlife-crisis-my-833c-amp-build.html They sound wonderful, with all the SET .......
101: Amp/Preamp Asylum, I've heard Both Raptors and Merrill Veritas (0.00)
Posted by Maxamillion on 2015-09-13, 09:24:01 (107.77.70.34)
And they sounded remarkably similar. Neither had that last bit of sparkle, detail and lifelike sound found in a great SET. They are both wonderful amps, but a little on the boring side for me. YMMV. : .......
102: Amp/Preamp Asylum, I owned a pair for several years (0.00)
Posted by Maxamillion on 2015-09-13, 08:32:44 (107.77.70.34)
Sold them after I built my 833C SET amps. The Raptors are very nice sounding amps, the SETs just have a more "technicolor" sound, a bit more detail, and believe it or not, better bass. I hear you abou .......
103: Tube DIY Asylum, Midlife Crisis is a Landfall Chassis (nt) (0.00)
Posted by Maxamillion on 2015-09-06, 17:59:45 (108.50.175.207)
nt .......
104: Tube DIY Asylum, Sounds like another reason to go amorphous! (0.00)
Posted by Maxamillion on 2015-09-05, 04:06:52 (166.137.252.125)
No crystal structure to degrade! It's a metallic glass. .......
105: Tube DIY Asylum, The Trannies on my 833C amps (0.00)
Posted by Maxamillion on 2015-09-04, 19:49:46 (108.50.175.207)
are amorphous (MetGlas) double-C cores with virgin teflon interwinding insulation. That's an ECC83 and a metric ruler in the picture for perspective. Given the materials, they'll probably be 75% broke .......
106: Tube DIY Asylum, RE: Source for HV caps (0.00)
Posted by Maxamillion on 2015-09-04, 19:34:17 (108.50.175.207)
I used 1000uF, 450V Panasonic T-HA in the 2.3kV supply for my 833C amps. 7 in series made 126uF (measured). I bypassed that assembly with (3) Mundorf M-tubecap 10uF, 1200V caps in series for a 3.33uF .......
107: Digital Drive, A Single ES9018 Sabre Chip has 8 DACs on it... (0.00)
Posted by Maxamillion on 2015-07-14, 18:39:14 (173.54.230.19)
So four DACs per channel can be done with ONE chip. See the Buffalo IIISE as an example. Nothing special there - if they were really using 8 chips they'd have 64 DACs!! See the block diagram in the ES .......
108: Digital Drive, RE: e-bay seller magicmarksy (0.00)
Posted by Maxamillion on 2015-07-04, 03:59:44 (166.137.252.110)
I think the link I posted, and the links within it, ought to be enough evidence. If I were you I'd find another source for the player. It's not the only one left on the planet. .......
109: Digital Drive, RE: e-bay seller magicmarksy (0.00)
Posted by Maxamillion on 2015-07-03, 15:21:44 (173.54.230.19)
FYI .......
110: Amp/Preamp Asylum, I Built it (0.00)
Posted by Maxamillion on 2015-06-29, 12:07:32 (216.0.238.6)
Here's my build thread over on DIYAudio: .......
111: Amp/Preamp Asylum, 200WPC of DHT SET Goodness (0.00)
Posted by Maxamillion on 2015-06-29, 04:42:56 (216.0.238.6)
833C DHT output tube fed by triode-strapped 6E5P driver tube in a direct coupled two-stage design. 2.3kV plate voltage on the 833C; A1 operation to 40W, A2 after that. .......
112: Amp/Preamp Asylum, Ya Want Heat? (0.00)
Posted by Maxamillion on 2015-06-28, 17:15:31 (173.54.230.19)
Have some of mine! The sound is worth it. In the summer I listen in the early morning. In the winter it's a nice heater for the room! .......
113: Tube DIY Asylum, Here's the Thread for You, Vinnie (0.00)
Posted by Maxamillion on 2015-06-28, 16:21:15 (107.77.70.53)
If you want to know all about 26 preamps. Looong, but packed with builds ranging from simple and cheap to complex and extravagant. Well worth the read. .......
114: Tube DIY Asylum, Coleman Regs can float, BTW (0.00)
Posted by Maxamillion on 2015-06-28, 12:52:43 (107.77.70.53)
to answer your question. I float them up to 250VDC in my 833C amps, pumping 10A of filament current through them. Very reliable and very quiet. Eli, you're in NJ too, right? I'm in Branchburg. Maybe y .......
115: Tube DIY Asylum, RE: Best Linestage Tube in Existence, IMO (0.00)
Posted by Maxamillion on 2015-06-28, 12:09:39 (173.54.230.19)
The cathode of the 26 is directly grounded. There is no cap in the grid circuit with this arrangement; the caps in the picture are a very small value film to bypass the battery for RF (optional) and t .......
116: Tube DIY Asylum, Sorry, they sound WAY too good (0.00)
Posted by Maxamillion on 2015-06-28, 11:04:31 (173.54.230.19)
To waste in an old radio. See my post below. Besides, soon enough over-the-air will be a dead medium, then the radios will really be useless. .......
117: Tube DIY Asylum, Best Linestage Tube in Existence, IMO (0.00)
Posted by Maxamillion on 2015-06-28, 10:39:51 (173.54.230.19)
Use Rod Coleman DC regulators on the filaments for a totally silent background. I also recommend battery grid bias through an input transformer, as shown in the schematic below. Here are a few pics of .......
118: Speaker Asylum, I have 38 of the 901 Series III (0.00)
Posted by Maxamillion on 2015-06-01, 17:59:22 (173.54.230.19)
4.5" Drivers on my workbench. 20 so far are refoamed with new cloth surrounds having the same compliance as the original foams; the rest will be soon. Intent is to build 8' tall line arrays with them. .......
119: SET Asylum, Schematic Enclosed (0.00)
Posted by Maxamillion on 2015-05-07, 18:00:18 (173.54.230.19)
No cap on the input. Not even a cap between the stages or in the cathode of the power tube. .......
120: SET Asylum, Four Cree Schottky Diodes in Series (0.00)
Posted by Maxamillion on 2015-05-07, 15:24:06 (107.77.76.80)
Are what I use under the 6E5P driver in my 833C amps. Gives just about the right voltage for this application, too. Sounds great! .......
121: SET Asylum, RE: A Set Amp for 84db Speakers (0.00)
Posted by Maxamillion on 2015-04-18, 11:08:40 (107.77.76.120)
These will work great...but you'll need to build them... Also not integrated. .......
122: SET Asylum, 2.3kV B+ (0.00)
Posted by Maxamillion on 2015-04-14, 14:17:15 (107.77.70.46)
Schematic may be found on DIYAudio in the "Midlife Crisis" thread if you're interested. .......
123: Tube DIY Asylum, RE: Jensen silver oil (0.00)
Posted by Maxamillion on 2015-04-11, 12:41:51 (107.77.76.51)
I had a Jensen copper foil PIO short out in a week with only 225V on it, in a cool preamp chassis. I avoid them in HV applications now. They do sound good...when they work... .......
124: Tubes Asylum, RE: EIMAC (0.00)
Posted by Maxamillion on 2015-04-08, 18:12:14 (173.54.230.19)
Any 833s available? .......
125: SET Asylum, 2-Stage DHT SET? Here's one... (0.00)
Posted by Maxamillion on 2015-04-04, 21:31:42 (173.54.230.19)
that doesn't need special easy-to-drive speakers to sound good. 85dB sensitivity, BAH, I laugh at 85dB! 6-way crossovers, BAH, bring on the 7-way! .......
126: SET Asylum, RE: How can you know which is more 'accurate' or 'truthful'? (0.00)
Posted by Maxamillion on 2015-04-03, 09:57:37 (216.0.238.6)
Unless of course you have a 200W SET. .......
127: SET Asylum, RE: Who thinks SS systems are generally more "truthful" than SET systems (0.00)
Posted by Maxamillion on 2015-04-03, 09:53:03 (216.0.238.6)
Negative feedback is another way to raise damping factor at the expense of power. .......
128: Tube DIY Asylum, 26 with AVC on output works GREAT! (0.00)
Posted by Maxamillion on 2015-03-17, 09:17:39 (216.0.238.6)
I use the Bent Audio slagleformer modules (silver wound) on the output of my 26 preamp, in parafeed (4.3uF PF cap) and they work great! The slagleformers have about 150H inductance, which is plenty wh .......
129: Tubes Asylum, RE: Nuts or not I hear what you hear ... (0.00)
Posted by Maxamillion on 2015-03-11, 09:56:12 (216.0.238.6)
Good to know I'm not alone in my dementia. .......
130: Tube DIY Asylum, OMG, you forgot the Quad-Around-Wrap technology! (0.00)
Posted by Maxamillion on 2015-03-09, 06:31:02 (107.77.70.57)
Doomed. .......
131: Tubes Asylum, RE: B+ is Regulated (0.00)
Posted by Maxamillion on 2015-03-08, 10:27:03 (173.54.230.19)
Lowest voltage I've seen is from the 5Y3G, about 270V. 270-225=45V, still quite a bit of headroom. .......
132: Tubes Asylum, RE: B+ is Regulated (0.00)
Posted by Maxamillion on 2015-03-08, 09:54:12 (166.137.252.54)
Well in all cases the voltage difference is 225-165=60V, since it's regulated, plenty to keep the capacitance of the plate CCS low. .......
133: Tubes Asylum, B+ is Regulated (0.00)
Posted by Maxamillion on 2015-03-08, 07:30:21 (107.77.76.82)
The preamp has a CCS-fed VR tube regulator holding the B+ at 225V, followed by a plate plate CCS that fixes plate current at 7mA. Voltage changes upstream shouldn't change the 26 operating point in th .......
134: Tubes Asylum, I Dunno...Is it? (0.00)
Posted by Maxamillion on 2015-03-07, 21:12:13 (166.137.252.119)
Perhaps you'd like to expound on your ideas, rather than hit and run? Rather than looking at the power supply as a source of power for the amplifier circuit, maybe we should look at the amplifier circ .......
135: Tube DIY Asylum, I Hope... (0.00)
Posted by Maxamillion on 2015-03-07, 20:35:12 (166.137.252.119)
There is more than a coupling cap between 1kV and your skull. Just sayin'... .......
136: Tubes Asylum, RE: 274B Rectifier (0.00)
Posted by Maxamillion on 2015-03-07, 14:15:39 (173.54.230.19)
The Valve Art 274B looks just like a 5U4, but the EML 274B mesh plate is another animal altogether. Just popped one in my 26 preamp and I have to say, it's the best sounding rectifier I've ever used i .......
137: Tube DIY Asylum, Can be done (0.00)
Posted by Maxamillion on 2015-03-07, 13:38:50 (107.77.76.20)
Just regulate the AC going into the amp. That's what I do with my 833C amps since I couldn't find a regulator for 2.3kV that would fit in the amps. All bias supplies are regulated, but B+ is not...and .......
138: Tube DIY Asylum, Autoformer VC on the Output is the Ticket for Me (0.00)
Posted by Maxamillion on 2015-03-06, 05:56:45 (216.0.238.6)
To me, using an autoformer VC and placing it on the output of the circuit is the ideal solution. I'm using the silver-wound slagleformers from Bent Audio and they are incredibly transparent, plus they .......
139: Tube DIY Asylum, RE: Schottky Rectifiers in series (0.00)
Posted by Maxamillion on 2015-02-28, 09:28:30 (173.54.230.19)
.01uF caps. Haven't had any issues in over one year of heavy use. .......
140: Tube DIY Asylum, RE: 1KV Schottky Rectifiers (0.00)
Posted by Maxamillion on 2015-02-28, 09:17:10 (173.54.230.19)
The caps help equalize the voltage across the stack, and also help to snub resonant spikes and shunt noise. I use .01uF, 1600V film caps. Recommended by the Valve Wizard, see link. .......
141: Tube DIY Asylum, RE: 1KV Schottky Rectifiers (0.00)
Posted by Maxamillion on 2015-02-27, 13:08:30 (4.28.6.246)
No experience with those surface mount diodes but I've used these 1200V TO-220 Cree Schottky diodes in my 833C amp to rectify the 2.5kV supply. 5 in series on each leg with a cap across each has worke .......
142: Tube DIY Asylum, RE: Hammond ...... (0.00)
Posted by Maxamillion on 2015-02-21, 04:48:05 (50.78.48.57)
If you look on the Hammond site there are picture of many items that show the top of the lams where the origin is indicated. I have had better luck with the Canada made units; the China ones I have ar .......
143: Tube DIY Asylum, RE: Hammond ...... (0.00)
Posted by Maxamillion on 2015-02-20, 07:04:47 (216.0.238.6)
It says it right on the top of the choke/transformer. Made in China or Made in Canada. .......
144: Tube DIY Asylum, ???? (0.00)
Posted by Maxamillion on 2015-02-03, 23:13:20 (46.253.45.222)
Paramagnetism in aluminum is an extremely weak, linear effect, and is in the SAME direction as the original magnetic field, so it is similar to an extremely weak, non-permanent, linear form of ferroma .......
145: Tube DIY Asylum, RE: Where does copper fall? (0.00)
Posted by Maxamillion on 2015-02-02, 19:28:33 (46.253.45.222)
IMO, copper is second to aluminum for a smaller chassis, and impractical for a large chassis. It would be first as a conductive ground plane, but it's very soft, very heavy, and tends to gum up your d .......
146: Tube DIY Asylum, Landfall Systems (0.00)
Posted by Maxamillion on 2015-01-31, 10:02:10 (166.137.252.91)
Landfall makes very sturdy aluminum chassis, in whatever size you need. I used them for my 833C monoblocks that weigh 180lbs each and they handled that just fine. .......
147: Tube DIY Asylum, RE: decoupling for driver/phase splitter (0.00)
Posted by Maxamillion on 2015-01-27, 17:28:33 (173.70.118.125)
"Doesn't everyone decouple every stage?" Hell, I usually build a separate power supply for every stage. .......
148: Tube DIY Asylum, Did you Invent the LCLC Filter? (0.00)
Posted by Maxamillion on 2015-01-27, 05:53:53 (173.70.118.125)
Is anyone who uses one now a devotee of DF and JM? Just curious, because I use them in everything I build, from low voltage SS to 2.5kV tube amps, decidedly CRITICAL inductance, or else it's just a ca .......
149: Digital Drive, RE: How far must a DAC board (0.00)
Posted by Maxamillion on 2015-01-22, 08:20:42 (216.0.238.6)
My Power Supply is in this chassis: And my DAC is in this chassis: And overall it looks like this: Absolutely quiet, sound is sublime. Size-wise, it's 90% output stage and power supply, 10% D .......
150: Tube DIY Asylum, RE: No Capacitor (0.00)
Posted by Maxamillion on 2015-01-08, 09:32:17 (216.0.238.6)
Yes, it uses a battery and the input transformer secondary windings. Any miniscule amount of grid current generated by the 26 goes to ground through the secondary and the battery - the secondary is li .......
151: Tube DIY Asylum, No Capacitor (0.00)
Posted by Maxamillion on 2015-01-07, 05:05:21 (216.0.238.6)
As I said, I do not need a capacitor before the grid, because the bias is applied to the ground side of an input transformer (see attached schema below). I tried it with a cap and the transformer sche .......
152: Tube DIY Asylum, Battery on the 26 grid (0.00)
Posted by Maxamillion on 2015-01-06, 19:23:50 (98.109.49.164)
A battery on the grid is about as clean a supply as you can get, and a lithium will last up to ten years in that job. I apply the bias through an input transformer (battery between transformer second .......
153: General Asylum, RE: My, what big tubes you have! (0.00)
Posted by Maxamillion on 2014-12-10, 11:41:41 (216.0.238.6)
No, I took them from Grandpa Munster's Lab. He used them to grow hair on bowling balls. .......
154: General Asylum, Here's mine (0.00)
Posted by Maxamillion on 2014-12-10, 09:14:56 (216.0.238.6)
Infinity RSIIb speakers, Zero One Mercury CD/HD player, DIY 26 preamp, DIY 833C SET monoblocks. .......
155: SET Asylum, 8000J of Energy Storage?? (0.00)
Posted by Maxamillion on 2014-11-07, 11:52:19 (216.0.238.6)
From the Nataudio site: "Equivalent energy from power supply is huge, example for bass response down to 20Hz, it is equal to no less then 8000 Joules (8kJ) of related capacitor type energy" Huh? 8000J .......
156: K&K Audio / Lundahl Transformers, Can LL1948 be Used for 2:1 Stepdown? (0.00)
Posted by Maxamillion on 2014-11-06, 19:23:19 (98.109.49.164)
From a 2V nominal source at the input of a preamp? I suppose that could be done with primaries in series and secondaries in parallel, correct? If so, would there be any sonic benefit versus an LL1676 .......
157: Tubes Asylum, NASA Advises Against it (0.00)
Posted by Maxamillion on 2014-11-01, 08:37:23 (98.109.49.164)
Why tempt fate when non-corrosive alternatives exist? .......
158: Tubes Asylum, Bad Idea (0.00)
Posted by Maxamillion on 2014-10-31, 13:30:42 (98.109.49.164)
I wouldn't use a caulk that released Acetic Acid anywhere near electronics. Just begging for corrosion issues. .......
159: Tubes Asylum, Try the Mullard GZ33 (0.00)
Posted by Maxamillion on 2014-10-22, 12:21:51 (216.0.238.6)
My favorite indirectly heated rectifier. Sounded excellent in my Supratek preamp when I was using that; smooth and very musical. When I bought the Mullard pair I have I paid less than half of what a M .......
160: Speaker Asylum, Still Listening to 80s Infinity Speakers (0.00)
Posted by Maxamillion on 2014-10-21, 20:03:06 (74.105.23.6)
Certainly I've upgraded them since then (external passive crossovers, new EMIM diaphragms from Apogee Acoustics), but I haven't heard anything better yet! .......
161: Tube DIY Asylum, An 833C amp Could Use it (0.00)
Posted by Maxamillion on 2014-10-21, 10:05:50 (216.0.238.6)
1500V isn't quite enough, though...my supply is 2300V. ;-) .......
162: Tube DIY Asylum, Love my Monolith Magnetics S-883 OPTs (0.00)
Posted by Maxamillion on 2014-10-21, 10:00:29 (216.0.238.6)
Obscenely expensive, even more than a 62lb double amorphous C-core with teflon insulation is expected to be, but oh what music they make out of an 833C! It came down to this - WTF else am I going to d .......
163: Tube DIY Asylum, I use one of those in my 833C Amps (0.00)
Posted by Maxamillion on 2014-10-21, 09:55:27 (216.0.238.6)
To run the fan...works great! .......
164: Tube DIY Asylum, RE: D.C. Filament transformer and choke size. (0.00)
Posted by Maxamillion on 2014-10-17, 18:25:16 (74.105.23.6)
The best solution for a hum-free DHT, IMO, is the Rod Coleman filament regulator. He sells them in various sizes as kits, and they work perfectly to produce a hum-free, very musical DHT circuit. Do a .......
165: Amp/Preamp Asylum, RE: How about with a speaker... (0.00)
Posted by Maxamillion on 2014-10-16, 17:14:58 (107.77.70.54)
Sounded great with my Infinity RSIIb speakers. Planar mids and tweeters, cone woofers in sealed cabinets. .......
166: Amp/Preamp Asylum, Yup 8K Input Impedance (0.00)
Posted by Maxamillion on 2014-10-16, 09:32:54 (216.0.238.6)
single ended and 16k balanced, per a discussion I had with Mark Gilmore a while back. I owned a pair for years and was very happy with them driving my Infinity RSIIB speakers. I sold them after I buil .......
167: Tube DIY Asylum, Even Cheaper than Penta (0.00)
Posted by Maxamillion on 2014-10-15, 12:50:42 (216.0.238.6)
is RFParts. $129.00 each for the 833C, Taylor brand. .......
168: Tube DIY Asylum, Makes Me Glad... (0.00)
Posted by Maxamillion on 2014-10-15, 06:34:04 (107.77.70.54)
that I built my big tube amps with the 833C graphite plate tube. Still produced, $140 per tube brand new from Penta Labs. .......
169: Tube DIY Asylum, Or, you can use an 85dB Speaker (0.00)
Posted by Maxamillion on 2014-10-07, 06:31:47 (198.228.200.160)
with a 200WPC, two-stage, direct coupled DHT SET amp and hear all the details, rock the house, and in general be as happy as a pig in shit. Statements of absolutes are often not as absolute as they se .......
170: SET Asylum, RE: Are you telling him to add these chokes or replace parts? (0.00)
Posted by Maxamillion on 2014-10-06, 09:34:21 (216.0.238.6)
"You can't hear a DHT amp properly until it has 20 Ohms or less chokes, period." Absolutes are a funny thing. Isn't it the ratio of the power supply DCR to the plate impedance of the output tube that .......
171: Tube DIY Asylum, RE: RF Oscillations (0.00)
Posted by Maxamillion on 2014-10-04, 10:50:52 (198.228.200.166)
You misread my post. My "does it make a difference" quote was not about a tiny amount of inductance or oscillation making a difference, it was about whether the transparency of a very low noise resist .......
172: Speaker Asylum, I Still Run Infinity RSIIb and LOVE Them (0.00)
Posted by Maxamillion on 2014-10-04, 06:06:33 (198.228.200.175)
Not minimonitors, for sure, but speaking of Infinity...The sealed enclosure for the woofers allows me to run them with my homebrew 200WPC SET amps and still have tight, clean bass...amazing! Replac .......
173: Tube DIY Asylum, RE: Or use metal foil (0.00)
Posted by Maxamillion on 2014-10-04, 05:22:38 (198.228.200.145)
I haven't had any issues with oscillation, on the scope, heat-wise, or sound-wise, and in listening tests (sighted), these are the most transparent resistors I've ever heard. Does it make a difference .......
174: Tube DIY Asylum, RE: Or use metal foil (0.00)
Posted by Maxamillion on 2014-10-03, 16:07:37 (74.105.23.6)
They're laser cut from a flat sheet of foil. They run the tracks in complementary directions in order to cancel out any inductance. Lots of info at this link: .......
175: Tube DIY Asylum, Or use metal foil (0.00)
Posted by Maxamillion on 2014-10-03, 09:19:37 (216.0.238.6)
The TX2575 are non-inductive as well. Those are what I use for stoppers, everywhere. Overkill? Perhaps. .......
176: Tube DIY Asylum, Here is the Lower Current Curve (0.00)
Posted by Maxamillion on 2014-09-12, 10:54:56 (216.0.238.6)
A few years ago I went to the trouble of measuring the forward voltage of those diodes at lower currents than the spec sheet. It turns out that the dynamic impedance is still very low at lower current .......
177: Tube DIY Asylum, RE: Love A2 as an Adjunct to A1 (0.00)
Posted by Maxamillion on 2014-09-09, 18:20:54 (74.105.23.6)
Those would make a great calibration standard for WAF, to set the zero point. .......
178: Tube DIY Asylum, RE: Love A2 as an Adjunct to A1 (0.00)
Posted by Maxamillion on 2014-09-09, 18:18:26 (74.105.23.6)
Infinity RSIIb. They should be up near 100dB at 40W. Of course the peaks need more, hence the 200W capability. They get as loud as I can stand without breaking a sweat. .......
179: Tube DIY Asylum, Love A2 as an Adjunct to A1 (0.00)
Posted by Maxamillion on 2014-09-09, 10:17:18 (216.0.238.6)
Agreed, I love A2 once the power gets high. My 833C SET monos do 40W in A1 and then transition to A2 up to 200W. Sound is incredible. Spice sims show typical harmonics in A1, with second dominating, t .......
180: Tube DIY Asylum, Simulate the Circuit in Spice First (0.00)
Posted by Maxamillion on 2014-09-09, 10:11:56 (216.0.238.6)
I don't build anything anymore without first simming it in LTSpice. My 833C amp sims were essential to building a 2.3kV amp that worked the first time I flicked the switch, with only minor adjustments .......
181: Tube DIY Asylum, Details (0.00)
Posted by Maxamillion on 2014-09-01, 07:29:34 (74.105.23.6)
Monoblock amplifiers with 833C output tube, 6E5P driver tube. Monolith Magnetics S-833 output transformers. Two stage, direct-coupled design, 2.3kV B+. Here's a link to all you'd ever want to know and .......
182: Tube DIY Asylum, I don't know about that... (0.00)
Posted by Maxamillion on 2014-09-01, 07:00:28 (74.105.23.6)
"If you NEED 100 Watts to power your speaker, you are simply NOT into tubes. You would be better served, performance-wise, with a good, real good solid state amp for such a speaker..." My 200WPC SET s .......
183: Tube DIY Asylum, RE: Best is to Incorporate Control into the Build (pics) (0.00)
Posted by Maxamillion on 2014-08-29, 09:14:39 (107.77.70.34)
Just for completeness, the 26 has a cascoded CCS on the plate, with the mu output of the CCS feeding Bent Audio (Slagle nickel core) autoformer volume controls at the output in a lossy parafeed config .......
184: Tube DIY Asylum, RE: Best is to Incorporate Control into the Build (pics) (0.00)
Posted by Maxamillion on 2014-08-28, 05:51:47 (216.0.238.6)
Here's the completed preamp. The 9V battery applies grid bias to the 26. It is fed through the LL1676 input transformer secondary so that there is no need for a DC blocking cap in the grid circuit .......
185: General Asylum, And There's more than one Class A, too! (0.00)
Posted by Maxamillion on 2014-08-27, 05:43:56 (216.0.238.6)
There's A1 with no grid current, and A2, where significant grid current is drawn. Also, combinations of the two (A1 up to certain power, then A2). .......
186: Speaker Asylum, Sounds like a Zu Druid (0.00)
Posted by Maxamillion on 2014-08-26, 13:34:41 (216.0.238.6)
One large driver from bass to upper mids, and a "supertweeter". .......
187: Tube DIY Asylum, Globes Rock (0.00)
Posted by Maxamillion on 2014-08-26, 11:41:25 (216.0.238.6)
I think they sound fuller and a bit warmer than the ST. I have no problems with microphonics, but the mounting scheme I use is a bit extreme (see above for pics). .......
188: Tube DIY Asylum, Best is to Incorporate Control into the Build (pics) (0.00)
Posted by Maxamillion on 2014-08-26, 11:24:20 (216.0.238.6)
I made my 26 Preamp tube mounts using 3mm thick aluminum plate, two pieces sandwiched together around a layer of Soundcoat sheet, that mounted to wooden supports using Deflex bushings I cut out of Def .......
189: Tube DIY Asylum, RE: "I find fixed bias to be much cleaner sounding" Interesting... I find it more like ... Solid scrape soundingnT (0.00)
Posted by Maxamillion on 2014-07-28, 05:58:06 (198.228.200.15)
We're all different, I guess. .......
190: Tube DIY Asylum, Nope, no coupling cap with the battery bias (0.00)
Posted by Maxamillion on 2014-07-27, 17:41:05 (74.105.23.91)
The battery feeds through an input transformer (LL1676), so no need for a coupling cap. See schematic. The battery is bypassed with a 10nF Multicap - the other cap and resistor shown are an RC network .......
191: Tube DIY Asylum, RE: I Try to Avoid Bypass Caps if possible (0.00)
Posted by Maxamillion on 2014-07-27, 14:20:36 (198.228.200.33)
Not if you put a CCS-fed VR tube regulator between that cap and the tube! That's what I do in my preamp, then ground the cathode and put a 9V battery feeding bias voltage to the grid. Very clean. ::: .......
192: Tube DIY Asylum, I Try to Avoid Bypass Caps if possible (0.00)
Posted by Maxamillion on 2014-07-27, 03:29:52 (74.105.23.91)
For small signal applications, cathode bias using diodes (such as Cree SiC Schottky types) sounds far better to me than a resistor and cap. For larger bias values I find fixed bias to be much cleaner .......
193: Tube DIY Asylum, RE: More on This... (0.00)
Posted by Maxamillion on 2014-07-24, 12:42:53 (216.0.238.6)
Here's a discussion on the topic among some hams, with a couple references cited as well. Apparently among the ham community balancing resistors went out with drum brakes. All I can say for sure is th .......
194: Tube DIY Asylum, Latest ARRL Handbook Recommends against the Resistors (0.00)
Posted by Maxamillion on 2014-07-24, 07:57:15 (216.0.238.6)
The newer ARRL handbook recommends against using voltage balancing resistors as they seem to cause more failures than they prevent. According to the 2005 ARRL Handbook (page 17.9) "shunting resistors .......
195: Tube DIY Asylum, I Actually Measured the Voltage Sharing with Caps (0.00)
Posted by Maxamillion on 2014-07-24, 06:47:23 (216.0.238.6)
up to 1040V using a high voltage probe. Results are shown in the attached graph. at 1040V, the difference between the highest and lowest diodes with caps across them was a MAX of 1.6V. Pretty darn .......
196: Tube DIY Asylum, RE: Eli & Max... (0.00)
Posted by Maxamillion on 2014-07-24, 06:38:26 (216.0.238.6)
Valve Wizard Merlin Blencowe seems to think caps can do the job... .......
197: Tube DIY Asylum, Actually... (0.00)
Posted by Maxamillion on 2014-07-23, 19:12:45 (74.105.23.91)
I constructed a bridge using 20 of the 1200V Cree Schottky diodes and used .01uF 1250V caps to equalize the voltage instead of resistors (see picture). It's been running for 7 months now rectifying th .......
198: Tube DIY Asylum, RE: Nice work, Max! (0.00)
Posted by Maxamillion on 2014-07-18, 21:11:42 (74.105.23.91)
Front Panel Express. It's engraved and infilled. .......
199: Tube DIY Asylum, RE: VR Tubes (0.00)
Posted by Maxamillion on 2014-07-16, 07:53:30 (216.0.238.6)
You have to add up the current demands of all parts of the two units, then make sure you have enough current from your PT and that your chokes can handle the higher current as well. Here's a link to a .......
200: Tube DIY Asylum, VR Tubes (0.00)
Posted by Maxamillion on 2014-07-16, 06:47:33 (216.0.238.6)
You don't say how much extra current your PS can supply, but you can make a very nice 255V shunt regulator for the phono pre using a CCS, a 0D3 and a 0C3 VR tube. The CCS feeds the series-connected 0D .......
201: Tube DIY Asylum, Unless You're Lois Lerner (0.00)
Posted by Maxamillion on 2014-06-28, 07:48:58 (198.228.201.155)
Then things just disappear forever... .......
202: Tube DIY Asylum, RE: What do you suggest? (0.00)
Posted by Maxamillion on 2014-06-22, 06:15:03 (198.228.201.176)
I've had good success with a PSAudio P5 regenerator. My incoming AC has about 3% distortion and what comes out of the P5 is at 0.2% - 0.3% distortion. It's not a cheap solution but it definitely works .......
203: Tube DIY Asylum, RE: Not Always an improvement (0.00)
Posted by Maxamillion on 2014-06-21, 08:57:04 (198.228.201.173)
Didn't mean to insinuate you were disputing it, sorry if it came across that way. Just trying to help folks avoid "improving" things in the wrong direction. .......
204: Tube DIY Asylum, Not Always an improvement (0.00)
Posted by Maxamillion on 2014-06-21, 07:46:13 (198.228.201.158)
As I stated below, many of these modules dump lots of AC noise into your earth ground and thus your chassis. This can raise the AC potential of the chassis and precipitate ground loop issues, in addit .......
205: Tube DIY Asylum, Can have a negative effect, too (0.00)
Posted by Maxamillion on 2014-06-20, 20:39:39 (74.105.24.242)
Especially the ones that use caps from hot and neutral to earth. They will inject some level of AC voltage into your chassis, which can result in more ground loop noise between components. I tried the .......
206: Tube DIY Asylum, Also Raises your Rp (0.00)
Posted by Maxamillion on 2014-06-15, 18:18:49 (71.187.236.56)
Not good if you need a lower Rp. Steve Bench also had a piece on starved filaments, BTW, along with an explanation of the effect. See link. .......
207: Tube DIY Asylum, RE: With the Steel Case on the K40s... (0.00)
Posted by Maxamillion on 2014-06-07, 14:05:12 (198.228.200.143)
Definitely something to keep in mind. Thanks, Tre...ya learn something every day. .......
208: Tube DIY Asylum, RE: With the Steel Case on the K40s... (0.00)
Posted by Maxamillion on 2014-06-07, 12:14:28 (198.228.200.30)
How much stray capacitance can there be in a K40? If it's 100pF, then a 1k drive impedance wouldn't roll off until 1.6MHz (-3dB). I suppose that could be an issue with much higher stray C and drive im .......
209: Tube DIY Asylum, With the Steel Case on the K40s... (0.00)
Posted by Maxamillion on 2014-06-07, 05:19:18 (198.228.200.44)
Why do you need to know the outer foil side? Just ground the body of the cap and you have a much better shield than an outer foil can provide. .......
210: Tube DIY Asylum, Landfall Aluminum Chassis (0.00)
Posted by Maxamillion on 2014-06-04, 20:27:13 (71.187.236.56)
I'm using an 18"x22"x4.25" Landfall Systems aluminum chassis in my 833C monos, which weigh 180lbs each. It takes two people to pick them up. They have 62lb OPTs, 4 power transformers and 6 chokes bolt .......
211: Tube DIY Asylum, Logic (0.00)
Posted by Maxamillion on 2014-06-04, 20:02:50 (71.187.236.56)
In my amps they are on the side in front, close to the input tubes. Being monos they are best placed close to the speakers, so longer ICs are required anyway, and the "flow-thru" arrangement is actual .......
212: Tube DIY Asylum, 200WPC (0.00)
Posted by Maxamillion on 2014-06-04, 19:55:21 (71.187.236.56)
2.3kV B+ on the 833C tube. Zero NFB, SET, 2 stage direct-coupled. 6E5P input tube. Air cooled with a fan under the 833C. Class A1 up to 40W or so, A2 above that. .......
213: Tube DIY Asylum, RE: Thoughts on layout? (0.00)
Posted by Maxamillion on 2014-06-03, 12:58:35 (216.0.238.6)
I ended up putting the inputs and outputs on the sides in the front of my amps and the PS stuff towards the back, so that the signal has a straight path from left to right (or right to left...they're .......
214: High Efficiency Speaker Asylum, RE: Drinking straws? (0.00)
Posted by Maxamillion on 2014-05-28, 09:56:59 (216.0.238.6)
The Mission speakers used something similar to that - they had a honeycombed insert in the port that was much the same as a bunch of straws packed in tight. Nice sounding small speakers. ::: TOP .......
215: Tube DIY Asylum, I'm Even using the Coleman Regulators... (0.00)
Posted by Maxamillion on 2014-05-28, 09:18:15 (216.0.238.6)
on the 833C DHT output tubes in my 200 WPC SET, at 10A, 10V! They're great! I have two in parallel per channel to get to 10A. .......
216: Amp/Preamp Asylum, Or start with a Tranny-based Passive... (0.00)
Posted by Maxamillion on 2014-05-22, 07:20:10 (216.0.238.6)
and build THAT into an active preamp. I use the Bent Audio unit as part of my #26 tube preamp (as the OPTs actually, in parafeed) and I couldn't be happier. It has the clarity of a passive with the sl .......
217: Tube DIY Asylum, I Went on Friday (0.00)
Posted by Maxamillion on 2014-05-21, 11:51:37 (216.0.238.6)
Picked up a Tektronix 2215 60MHz scope with two new 100MHz probes for $100; works perfectly. Also got a box of 8 or 9 HV oil caps for $10, 8 tubes of various types (301A, 80, 6BY5, 0D3, 0A3), and asso .......
218: K&K Audio / Lundahl Transformers, PS: Cree SiC Schottky Diode Bias (0.00)
Posted by Maxamillion on 2014-05-17, 06:59:58 (107.19.76.75)
At 3.6V. So, essentially fixed bias. Lundahl grid choke on the 6E5P as well. .......
219: K&K Audio / Lundahl Transformers, 6E6P (0.00)
Posted by Maxamillion on 2014-05-17, 05:43:27 (107.19.76.75)
I use the 6E5P, which is very similar to the 6E6P with a different pinout, in my two stage Midlife Crisis amps, triode strapped with UF4007 plus 200R, and it sounds great at 190V and 26mA. It's direct .......
220: Tube DIY Asylum, RE: This is Right up Your Alley, Jeff! (0.00)
Posted by Maxamillion on 2014-05-15, 14:27:53 (64.134.166.32)
Cool story. In building my amp I of course took extra precautions in terms of wire insulation, distances from hot points to grounded points, bleeder resistors, elimination of sharp edges/points, coron .......
221: Tube DIY Asylum, This is Right up Your Alley, Jeff! (0.00)
Posted by Maxamillion on 2014-05-15, 06:55:02 (50.43.240.70)
You should love this sound, Jeff. The 833C lets me use a power supply with 600R+ DCR (LCLC) on the output stage and still meet your low DCR criterion of PS DCR being 10X less than output tube plate re .......
222: Tube DIY Asylum, Total 375J per Monoblock (0.00)
Posted by Maxamillion on 2014-05-14, 09:11:45 (198.228.228.166)
BTW, the separate power supply for the driver stage has another 35J of energy storage for a total of 375J per monoblock; those numbers are only counting the final power supply capacitance in each filt .......
223: Tube DIY Asylum, It's Docile as a Kitten (0.00)
Posted by Maxamillion on 2014-05-13, 18:11:18 (198.228.228.143)
Really. Once I got over the initial hesitance to play with multi-kilovolts it all fell into place rather nicely. You have to hear what 340J of energy storage at 2.3kV (per channel) sounds like in an S .......
224: Tube DIY Asylum, Shunt regulator (0.00)
Posted by Maxamillion on 2014-05-13, 16:20:21 (198.228.228.176)
Or put a shunt regulator with a beefy pass MOSFET under the power tube cathode and there's no need for a bypass at all, and because it has a small set current going through it at all times, it will ha .......
225: Tube DIY Asylum, Mu Follower with AOT2N60 (0.00)
Posted by Maxamillion on 2014-05-13, 15:10:55 (198.228.228.177)
My Midlife Crisis SET mono amps are direct-coupled, two stage, with a triode-strapped 6E5P driver loaded with an AOT2N60 in a mu-follower configuration, using a separate cascoded CCS loading a resisto .......
226: Tube DIY Asylum, Starved Tube Watchout, Higher Plate Resistance (0.00)
Posted by Maxamillion on 2014-04-11, 05:37:44 (198.228.200.20)
Bench's work does show decreased distortion, but at the cost of increased plate resistance. If your circuit is sensitive to that, you may create more problems than you solve. As always, be sure the cu .......
227: Speaker Asylum, Bose Line Array? (0.00)
Posted by Maxamillion on 2014-04-10, 13:13:15 (216.0.238.6)
I have a set of Bose 901 series III that I picked up for free. That gives me 18 4.5" drivers...I was toying with the idea of turning them into a pair of line arrays, I wonder if anyone has ever done t .......
228: Tube DIY Asylum, Here's Where I Bought the Caps for my 833C Tubes (0.00)
Posted by Maxamillion on 2014-04-02, 10:43:10 (216.0.238.6)
See Link. .......
229: Speaker Asylum, Cardas Copper Litz in Teflon (0.00)
Posted by Maxamillion on 2014-03-13, 13:05:57 (207.179.20.177)
Re-wired my Infinity RSIIbs with it. 17.5ga for tweeters, 15.5ga for mids, 11.5ga for woofers, run right from the crossover, which I moved external to the speaker. Sounds excellent! ::: TOPIC: .......
230: Tube DIY Asylum, Using the 430uF, 700V TC in my 833C SET (0.00)
Posted by Maxamillion on 2014-03-13, 12:57:32 (216.0.238.6)
On the driver stage filter. 430uF mega-cap...hey, that grid current has to come from somewhere! It also serves as a shield of sorts between the input circuits and the power supply. .......
231: SET Asylum, They're Done! And They Sound Great! (0.00)
Posted by Maxamillion on 2014-02-21, 21:11:17 (173.63.2.78)
They drive my Infinity RSIIb speakers with no sweat at all. The sound is wonderful. That's all I can say - most surprising is the bass, it's better than what I get from my 500WPC class D monos! Just t .......
232: Tube DIY Asylum, Sears Craftsman Professional 400W Iron (0.00)
Posted by Maxamillion on 2014-02-15, 06:51:02 (198.228.200.153)
I use a big Craftsman 400W iron in such cases. It will solder just about anything, and has a heavy tip that holds lots of heat. 10gauge wire onto big binding posts is no problem. I bought it several y .......
233: Tube DIY Asylum, For a power amp, not a big issue. Preamp is different (0.00)
Posted by Maxamillion on 2014-02-09, 08:26:44 (198.228.200.163)
Having a small overshoot and a little wiggle on a zero feedback SET power amp output doesn't bother me sound-wise, having the same on a preamp bothers me quite a bit. I think the high frequency abbera .......
234: General Asylum, Just buy a New Violin (0.00)
Posted by Maxamillion on 2014-02-03, 07:09:32 (71.187.236.197)
According to the NYT, even most master violinists can't tell the difference, and if they can, most prefer the new violins! .......
235: Speaker Asylum, Apogee Acoustics in Oz (0.00)
Posted by Maxamillion on 2014-01-30, 05:59:07 (4.28.6.246)
Apogee Acoustics in Autralia make EXCELLENT replacement diaphragms for the EMIM. They are truly better than new - I replaced all the EMIMs in my RSIIB's and the improvement was drastic. EMITs are rea .......
236: SET Asylum, RE: Thanks, did I mention 190uV Noise Floor? (0.00)
Posted by Maxamillion on 2014-01-30, 05:52:17 (4.28.6.246)
I get your point. My listening environment is very different from where that amp was tested, which is on my basement workbench about 3 feet from the main electrical panel, and under bright fluorescent .......
237: Speaker Asylum, An Example (0.00)
Posted by Maxamillion on 2014-01-29, 10:09:05 (4.28.6.246)
The external crossovers for my Infinity RSIIb speakers - lots of air between sections. .......
238: Speaker Asylum, Air (0.00)
Posted by Maxamillion on 2014-01-29, 09:45:10 (198.228.201.166)
The best material is air, meaning distance. You could use a shielding material such as steel or mu metal or TI-Shield, but it will interact with the coil's magnetic field to some extent. If you're goi .......
239: Tube DIY Asylum, RE: That Graph is Specifically for 1amp, 600V Cree Schottky Diodes (0.00)
Posted by Maxamillion on 2014-01-26, 05:41:52 (198.228.200.171)
Yes, I constructed the "zoomed" graph because the Cree datasheet curve was mostly concerned with the higher I region. I stopped at 1-2 mA because I don't bias anything below that - what are you intend .......
240: Tube DIY Asylum, That Graph is Specifically for 1amp, 600V Cree Schottky Diodes (0.00)
Posted by Maxamillion on 2014-01-25, 13:41:11 (198.228.200.160)
Cree part #CSD01060A. Just for completeness...;-) .......
241: SET Asylum, Thanks, did I mention 190uV Noise Floor? (0.00)
Posted by Maxamillion on 2014-01-18, 21:25:02 (74.105.3.169)
I was pretty surprised to find it was that low considering all the magnetics shoved in that single chassis (4 power trannies, 6 chokes, one OPT, one fan). Guess that layout stuff really works... ;-) H .......
242: Tube DIY Asylum, RE: kilovolt measurement equipment (0.00)
Posted by Maxamillion on 2014-01-16, 06:09:21 (4.28.6.246)
You can use any multimeter as long as you have a high voltage probe. I use one that is two pieces - the inner part is good up to 5kV and the outer part that slips on over the inner is good up to 50kV! .......
243: SET Asylum, RE: WOWEEWOW!! Attention, many Electrostatic Loudspeakers are looking for you! (0.00)
Posted by Maxamillion on 2014-01-13, 13:28:50 (4.28.6.246)
Not Tango, Monolith Magnetics. The OPT weighs 62 lbs. Here's a picture of the double-C core before strapping and potting with an ECC83 for reference: .......
244: SET Asylum, RE: I thought about multiple chassis (0.00)
Posted by Maxamillion on 2014-01-11, 13:35:50 (74.105.3.169)
They're surprisingly good sounding for an inexpensive 2-way. I got them for free and made them my shop speakers; the cabinets are rough but they work great, and I don't feel bad about piling stuff on .......
245: SET Asylum, Thanks (0.00)
Posted by Maxamillion on 2014-01-11, 09:03:20 (74.105.3.169)
I don't know about that, but thanks for the compliments! I have to give credit for the circuit inspiration to Michael Koster over at DIYAudio who developed the "Meteor" amp - mine is an evolution of t .......
246: SET Asylum, I thought about multiple chassis (0.00)
Posted by Maxamillion on 2014-01-11, 07:52:30 (74.105.3.169)
But then I thought it would be even more of a challenge to fit it all into a single 18"x 22" chassis per side, and not get too much noise or hum. Also, having that much voltage in an umbilical didn't .......
247: SET Asylum, Schematic (0.00)
Posted by Maxamillion on 2014-01-11, 05:38:05 (74.105.3.169)
Here's an LTSpice schematic: This is what I built, except V7 is no longer a shunt regulator, as stated, it's a simple cascoded CCS feeding a resistor divider to set the voltage for the MOSFET gate; .......
248: SET Asylum, Construction Details (0.00)
Posted by Maxamillion on 2014-01-11, 05:22:34 (74.105.3.169)
Here's a shot of the underside: The 833 B+ is wired with 5kV rubber insulated test lead. The driver is wired with Belden silver plated copper in Teflon for the + leg and Cardas copper litz in Teflo .......
249: SET Asylum, Here's a Picture with its "Protection" (0.00)
Posted by Maxamillion on 2014-01-10, 21:58:46 (74.105.3.169)
2300V gives a nasty nip! Pyrex glass cylinder helps to keep the family alive! .......
250: SET Asylum, One 200W SET Monoblock Complete, One to Go (0.00)
Posted by Maxamillion on 2014-01-10, 21:52:49 (74.105.3.169)
The right channel of my Midlife Crisis is complete and running. 200WPC, two-stage SET, using the 833C output tube and the 6E5P (triode strapped) driver. 2300VDC B+, all supplies choke input LCLC. .......
251: Tube DIY Asylum, Another Shot (0.00)
Posted by Maxamillion on 2014-01-10, 21:42:29 (74.105.3.169)
The Midlife Crisis lives! 200WPC, SE DHT goodness. .......
252: Tube DIY Asylum, Kinda like my 833C (0.00)
Posted by Maxamillion on 2014-01-10, 21:39:49 (74.105.3.169)
100W filament, 10A, 10V. .......
253: Tube DIY Asylum, Interesting concept, but why not just use Diodes? (0.00)
Posted by Maxamillion on 2014-01-04, 06:05:07 (173.54.233.10)
Why not just use diodes in the cathode, either LEDs or my favorites, SiC schottky diodes? You get very, very low dynamic resistance, no need for a capacitor bypass, and you don't need another power su .......
254: Vintage Asylum, Here's what I did with Mine (0.00)
Posted by Maxamillion on 2013-12-19, 20:04:35 (173.54.233.10)
There are a few other threads on AK as I went through the rebuild. It's now in my wife's vintage system - she listens to it when she works out. .......
255: Tube DIY Asylum, How about one with 20 Diodes? (0.00)
Posted by Maxamillion on 2013-12-19, 19:39:40 (173.54.233.10)
This one is in my 833C monos. 2500VAC input. .......
256: Tube DIY Asylum, You Can Always Make Sockets if Need Be (0.00)
Posted by Maxamillion on 2013-11-11, 21:12:14 (70.105.172.84)
I did that for my 833 amp I'm building. I don't trust the new Chinese versions and NOS Johnsons seem to be unobtainium. Made them from a teflon bar and aluminum electrical connectors. See picture. .......
257: Tube DIY Asylum, Landfall is a Good Option (0.00)
Posted by Maxamillion on 2013-10-31, 21:50:02 (70.105.172.84)
These guys are easy to work with and have a very solid modular aluminum chassis system that would work well for you. Ask for Dave. I'm currently building 150lb+ monoblocks on their chassis so they're .......
258: Amp/Preamp Asylum, They Work Great In Active Preamps, too (0.00)
Posted by Maxamillion on 2013-10-25, 21:22:35 (70.105.172.84)
I built a 26 DHT preamp using the Slagleformers simultaneously as output "transformers" and volume controls in a parafeed configuration. Sounds very, very good. Here's a frequency response plot of .......
259: General Asylum, RE: PS Audio P5 Fan noise??? (0.00)
Posted by Maxamillion on 2013-09-23, 18:57:05 (173.54.232.68)
I have a P5. It is a MUCH better unit than the PPP I traded in for it. Much better build quality, quiet, lower distortion, more reliable. Just better in every way. .......
260: Tubes Asylum, RE: what else did you see @ Kutztown? (0.00)
Posted by Maxamillion on 2013-09-21, 18:12:07 (173.54.232.68)
Well of course lots of old radios and radio parts, which I like to look at but am not really into at this stage of my life (I have a closet full of old tube radios I haven't touched but intend to rest .......
261: Tubes Asylum, Good Day at Kutztown Today (0.00)
Posted by Maxamillion on 2013-09-21, 13:46:13 (173.54.232.68)
Got a dozen #80 rectifier tubes (all very strong) for $30, three #26 balloon tubes (also very strong) for $18 and five assorted VR tubes for $10. Still shopping when the wife came to get me, but all i .......
262: Tube DIY Asylum, Look at the Plate Curves (0.00)
Posted by Maxamillion on 2013-08-23, 12:56:59 (173.54.232.68)
On the datasheets. 15mA is right in the sweet spot at 175V. The 11mA listed in the characteristics is a "typical" value, not a max. They sound MUCH better to me at the higher current. No reliability i .......
263: Tube DIY Asylum, The 7193s like current (0.00)
Posted by Maxamillion on 2013-08-20, 19:42:21 (173.54.232.68)
I modded my Supratek preamp to run 7193s instead of 6SN7s and the 7193s sounded much better with higher Ia. I settled on 15mA (14.6 to be precise) using 3.4V SiC Schottky diode bias in the cathode ::: .......
264: Tube DIY Asylum, Old Dremel Wire Wheels (0.00)
Posted by Maxamillion on 2013-08-17, 21:25:18 (74.105.4.110)
I save the old used up wire wheels (stainless steel) from my dremel and use them to clean leads pre-soldering. The worn-down bristles from the wheel wrap right around the leads and with a few quick ba .......
265: SET Asylum, RE: Or You can Just Make a Really Big SET (0.00)
Posted by Maxamillion on 2013-07-15, 13:13:01 (166.147.123.32)
Nah, way less than 20%, I'd say. The OPT has a 15kg amorphous Metglas double C core. Sims show a nice symmetrical waveform for a 1kHz sine at around 200wpc. Measured bandwidth of the OPT is 7Hz to 66k .......
266: SET Asylum, Or You can Just Make a Really Big SET (0.00)
Posted by Maxamillion on 2013-07-14, 18:05:59 (74.105.4.110)
Like 200WPC or so, with zero NFB. My custom OPTs are done and should ship this week. Then it's time to wire it all up... .......
267: General Asylum, RE: Pulsed Electron Alignment ? Huh ? (0.00)
Posted by Maxamillion on 2013-06-30, 19:17:26 (74.105.4.110)
You can still see the remnants of the cocaine that guy snorted off the top of the black box just before he thought up that explanation. Seriously, look at the picture. .......
268: Tweakers' Asylum, Partial to the OPA827 (0.00)
Posted by Maxamillion on 2013-06-30, 13:05:17 (198.228.200.18)
I much prefer the OPA827. It's like the 627 on steroids and HGH, or a cross between a 627 and an AD opamp. Very lively, but musical. Of course, everyone likes what they like... .......
269: Amp/Preamp Asylum, RE: de Paravicini contribution (0.00)
Posted by Maxamillion on 2013-06-25, 18:37:28 (74.105.4.110)
GNF. Yuk. .......
270: Amp/Preamp Asylum, I've had Raptors for several years (0.00)
Posted by Maxamillion on 2013-06-22, 15:19:28 (74.105.4.110)
They are excellent amps, with power to spare yet very delicate when that's appropriate. Had the Raven before that - it sounds a lot like the Raptors, with a little less bass authority, but not much. I .......
271: SET Asylum, My Solution (0.00)
Posted by Maxamillion on 2013-06-15, 10:40:35 (198.228.200.174)
For my 26 preamp I built an isolated sub-assembly from a double layer of 4mm thick aluminum sandwiching a sheet of soundcoat damping material, and isolated from the chassis with deflex bushings. No .......
272: SET Asylum, RE: 300B Bottlehead BeePre vs. a "modern" 26 preamp? (0.00)
Posted by Maxamillion on 2013-06-13, 19:59:50 (71.172.138.173)
I found that parafeeded autoformer outputs (which double as volume controls) brought my 26 pre to a new level. Battery bias through an input transformer sounds clean and clear. Cascoded CCS with 90V h .......
273: SET Asylum, RE: You are sure living up to your moniker there my friend. (0.00)
Posted by Maxamillion on 2013-05-31, 21:30:27 (71.172.138.173)
Ok, very expensive. $5k for the pair. They are specifically custom designed for the 833 tube. Monolith does however have other designs for the likes of the 845, 300B, etc. .......
274: SET Asylum, RE: You are sure living up to your moniker there my friend. (0.00)
Posted by Maxamillion on 2013-05-31, 05:34:47 (206.228.220.38)
Monolith Magnetics is making the transformer. The core is the Metglas AMCC1000 from Elna Magnetics (link below), amorphous alloy, the dielectric is teflon. Each OPT double core alone weighs 14.2kg (no .......
275: SET Asylum, I'm Currently Building a 2-Stage 195WPC SET (0.00)
Posted by Maxamillion on 2013-05-30, 18:02:53 (71.172.138.173)
Using 6E5P as the input tube into an 833C with a MOSFET source follower providing the current for A2 (I don't count that as a separate stage since it sits on top of the 6E5P plate as a gyrator load). .......
276: Tubes Asylum, Had a Similar Problem with a Grundig NF1 (0.00)
Posted by Maxamillion on 2013-04-07, 06:47:20 (71.172.138.193)
Recapping the unit with new electrolytics and film caps and replacing the selenium rectifier with a silicon one resolved it. Need a resistor to drop the extra voltage from the Si rectifier. Nice sound .......
277: Tube DIY Asylum, Solens are fine in a PS - They're in my 26 (0.00)
Posted by Maxamillion on 2013-04-06, 21:05:16 (71.172.138.193)
Especially if you have good chokes in the supply and a regulator after them. Far, far better than electrolytics. The pic shows the inside of my 26 preamp power supply, with both 47uF and 100uF Sole .......
278: Tube DIY Asylum, Right Hand Rule (0.00)
Posted by Maxamillion on 2013-02-10, 09:46:19 (173.54.229.215)
Thumb is the direction of current flow, fingers are the magnetic field lines. .......
279: Tube DIY Asylum, I know this Pales in Comparison (0.00)
Posted by Maxamillion on 2013-02-07, 21:01:26 (173.54.229.215)
but I'm working on an amp with two of these: Only 2kV B+, though. I'm a wuss... .......
280: Tweakers' Asylum, RE: Op Amp question OPA2134 substitution (0.00)
Posted by Maxamillion on 2013-01-05, 07:59:09 (166.137.101.149)
OPA827 do it for me. You need two on a Browndog adapter to replace one 2134. Fast, dynamic, and crystal clear without being harsh. Love 'em. .......
281: Amp/Preamp Asylum, The "Dipped in a Bucket of Rust-Oleum" Look (0.00)
Posted by Maxamillion on 2012-12-22, 10:35:23 (173.63.2.10)
Is the builder really lazy or is he going for a modern art, Jackson Pollock vibe? Cochrane's amps looked like that too, if I remember correctly. .......
282: Tweakers' Asylum, Jensons are a DEFINITE NO-NO (0.00)
Posted by Maxamillion on 2012-12-21, 17:30:23 (173.63.2.10)
I have personally had their copper foil PIOs short completely at high voltage within days of installation, and there are NUMEROUS other reports of them failing in amps. Do a search, you'll find the st .......
283: Tweakers' Asylum, Reports of Mundorf SIO Heat Failure (0.00)
Posted by Maxamillion on 2012-12-21, 13:37:11 (198.228.200.149)
There have been reports of SIO caps failing in hot amps. According to this link Mundorf themselves say the oil destroys the silver foil in hot environments... .......
284: K&K Audio / Lundahl Transformers, Primary Inductance LL1690 vs LL1676 (0.00)
Posted by Maxamillion on 2012-12-14, 09:00:17 (206.228.222.37)
How does the primary inductance of the LL1690 compare to that of the LL1676? I know that the LL1676, used backwards with primary windings in series is ~200H - how does that compare to the LL1690, used .......
285: K&K Audio / Lundahl Transformers, Reporting Back as Promised (0.00)
Posted by Maxamillion on 2012-11-27, 12:35:27 (206.228.222.38)
The 26 preamp using the mu output from the plate CCS sounds fantastic! The lower output impedance of the mu output combined with a lossy parafeed topology into the Bent Audio autoformer volume control .......
286: K&K Audio / Lundahl Transformers, It Works Great (0.00)
Posted by Maxamillion on 2012-11-25, 18:24:16 (166.137.88.172)
Major improvement...keep it simple wins again, one less cap, one less grid leak resistor per side. Better clarity, more impactful bass...a lot more. Thanks, Kevin! .......
287: K&K Audio / Lundahl Transformers, RE: Kevin one more ?? Please - RE: Applying DC Grid Bias Through LL1676 (0.00)
Posted by Maxamillion on 2012-11-24, 14:28:59 (166.137.88.149)
Thanks, Kevin. I have it set up now to inject the grid bias after a DC blocking cap, so I have both the LL1676 and a cap in the circuit. It sounds very nice, but if I can dispense with the cap and inj .......
288: K&K Audio / Lundahl Transformers, Kevin one more ?? Please - RE: Applying DC Grid Bias Through LL1676 (0.00)
Posted by Maxamillion on 2012-11-24, 13:02:53 (166.137.88.152)
So Kevin, just to be sure, you're saying there is no problem applying 9V battery grid bias to the 26 grid through the secondary of the LL1676 input transformer, with no DC blocking cap, right? The sma .......
289: Tube DIY Asylum, I Prefer Larger Value Bypasses (4.7uF or so) (0.00)
Posted by Maxamillion on 2012-10-29, 07:39:02 (206.228.222.38)
For those supplies I can't do all film (such as high current filaments or SS), I prefer to bypass the large electrolytics with a good sized PP film cap (3-5uF, 4.7uF usually). I find this cleans up an .......
290: Tube DIY Asylum, No, I mean High Voltage (0.00)
Posted by Maxamillion on 2012-10-28, 10:24:57 (198.228.200.161)
Or High Tension, as it's also known. Of course high temperature is likely to exacerbate any problems... .......
291: Amp/Preamp Asylum, I've Had Raptors Since 2008 ($5000/pr then) (0.00)
Posted by Maxamillion on 2012-10-23, 14:04:56 (206.228.222.37)
And the Raven prior to that. I upgraded to the Raptors because I wanted more power for my Infinity RSIIb speakers. I paid $5000 for the pair (minus Raven trade-in) and I'm not sorry even though the pr .......
292: Tube DIY Asylum, Shield is an extension of the box (0.00)
Posted by Maxamillion on 2012-10-23, 10:21:36 (206.228.222.38)
So I ground it at both ends to the chassis. Think of it as one big box with a tunnel in between for the cable. I haven't had any ground loop problems from this arrangement. .......
293: Tube DIY Asylum, Beware Jensen Copper Foil PIO in HT apps (0.00)
Posted by Maxamillion on 2012-10-20, 15:52:54 (173.54.232.141)
So I had heard in the past that the Jensen copper foils (aluminum tube) had problems with DC leakage, but that Jensen had fixed it...not the ones I got. I wanted some of that midrange bloom they are f .......
294: Tube DIY Asylum, Yes, I did (0.00)
Posted by Maxamillion on 2012-10-15, 05:21:32 (173.63.95.96)
I looked at it this way. To buy something with that level of parts and that much time for assembly (the mounting scheme for the 26 alone took me weeks to think up and an entire day to make!) would hav .......
295: Tube DIY Asylum, Interesting thought (0.00)
Posted by Maxamillion on 2012-10-14, 12:04:56 (166.137.88.159)
But the idea of deliberately introducing HF into the system freaks me out a bit...my ears are ringing just thinking about it...;-) .......
296: Tube DIY Asylum, RE: Still More details (0.00)
Posted by Maxamillion on 2012-10-14, 12:01:42 (166.137.88.159)
I thought about it but figured a Duelund CAST was better to send a signal through than an alkaline battery...in the end, we must make choices. The battery is isolated from the signal by a 374Kohm Vish .......
297: Tube DIY Asylum, RE: Still More details (0.00)
Posted by Maxamillion on 2012-10-14, 11:17:21 (166.137.88.169)
The Lundahl is completely quiet in choke input, so no worries there. I'm using the LL1685 17H in both positions. The B+ wiring is Connex OCC copper in teflon, 18 gauge, and the filament + wire is Beld .......
298: Tube DIY Asylum, RE: Even More details (0.00)
Posted by Maxamillion on 2012-10-14, 08:34:07 (166.137.88.153)
I'm using a lossy parafeed setup with a 1uF Duelund Cast copper foil PIO primary cap. The lossy parafeed bypass is a 3.3uF Mundorf Supreme in series with an 8080ohm TX2575 resistor. Without the LPF th .......
299: Tube DIY Asylum, More details (0.00)
Posted by Maxamillion on 2012-10-14, 08:21:55 (166.137.88.172)
I'm using the "mu output" of the CCS to feed the autoformer in a lossy parafeed setup; in other words I'm taking the signal from the top of the CCS set resistor instead of the bottom.The autoformer la .......
300: Tube DIY Asylum, I'll work up a schema in a few days (0.00)
Posted by Maxamillion on 2012-10-13, 22:45:44 (173.63.95.96)
Have to figure out TinyCad first. Right now it's in my head... .......
301: Tube DIY Asylum, Quiet as a churchmouse (0.00)
Posted by Maxamillion on 2012-10-13, 18:25:56 (166.137.88.170)
This pre is silent. Black. The Rod Coleman filament supply boards are a breakthrough in keeping DHTs quiet. Add in choke input on B+ and filaments, CCS loaded VR tubes, CCS plate load, and an input tr .......
302: Tube DIY Asylum, RE: My New DIY 26 Preamp (0.00)
Posted by Maxamillion on 2012-10-13, 16:08:04 (173.63.95.96)
Frequency response at -6, -12, -18 and -24dB on the volume control. .......
303: Tube DIY Asylum, My New DIY 26 Preamp (0.00)
Posted by Maxamillion on 2012-10-13, 16:05:44 (173.63.95.96)
Sounds excellent! Bent Audio Slagleformer volume control modules on the outputs also double as output autoformers. Lundahl LL1676 transformers on the inputs for galvanic isolation, pha .......
304: Tube DIY Asylum, Try it, it works (0.00)
Posted by Maxamillion on 2012-09-16, 10:27:44 (166.137.88.154)
Use the Dremel stainless steel wire wheel, medium speed and be sure the wheel is rotating toward the ends of the wire, that way the strands won't get tangled in the wheel. Untwist and fan out the indi .......
305: High Efficiency Speaker Asylum, It was me (0.00)
Posted by Maxamillion on 2012-09-15, 21:33:46 (173.63.95.96)
Still do it that way. Works well for me. Stainless steel wire wheel, medium speed. Of course it's still an extra step compared to non-litz wire. .......
306: Tube DIY Asylum, Use the brush that dremel sells (0.00)
Posted by Maxamillion on 2012-09-15, 09:03:00 (166.137.88.165)
It's made for the Dremel and is just the right size. Use the wire wheel with the bristles around the circumference, not the one with them all bunched up like a broom. Stainless works better than carbo .......
307: Tube DIY Asylum, Dremel w/ SS wheel works fine, no solder pot needed (0.00)
Posted by Maxamillion on 2012-09-14, 21:26:04 (173.63.95.96)
see post above. .......
308: Tube DIY Asylum, No Need For Any Solder Pots. Use a Dremel. (0.00)
Posted by Maxamillion on 2012-09-14, 21:19:12 (173.63.95.96)
I've been using Cardas copper litz in speakers for wiring up the components and my preamp builds for the DC return wires and umbilicals. The easy way to get the enamel off is with a dremel and stainle .......
309: Amp/Preamp Asylum, The Raptors (0.00)
Posted by Maxamillion on 2012-08-10, 19:40:09 (166.137.88.168)
Powering Infinity RSIIb speakers. .......
310: Amp/Preamp Asylum, I've used them on Zu Druids and Infinity RSIIb (0.00)
Posted by Maxamillion on 2012-08-10, 08:14:31 (166.137.88.144)
And they sound excellent on both of those VERY different speakers. Currently rocking the Infinities (with major upgrades to crossovers, mid diaphragms, etc.) and I haven't heard anything I prefer yet! .......
311: Amp/Preamp Asylum, I demo-ed the Gilmore amp vs the Nuforce (0.00)
Posted by Maxamillion on 2012-08-10, 08:06:30 (166.137.88.144)
I much preferred the Gilmore. The Nuforce Ref9 SE V2 sounded harsh by comparison. Not really close. .......
312: Amp/Preamp Asylum, I've had both the Raven and Raptors (0.00)
Posted by Maxamillion on 2012-08-10, 08:02:47 (166.137.88.144)
They have a very similar sound. The Raptors have a little more slam in the bass and are perhaps a tiny bit clearer sounding, probably due to having two completely separate power supplies. If you want .......
313: Amp/Preamp Asylum, PS: (0.00)
Posted by Maxamillion on 2012-07-31, 05:13:07 (166.137.88.157)
If you audition them, try both gain settings (switch on back). I found the lower setting sounded better with my Supratek preamp while the higher setting sounded better with my DIY 26 preamp. ::: TOPIC .......
314: Amp/Preamp Asylum, I own a pair (0.00)
Posted by Maxamillion on 2012-07-31, 04:51:01 (166.137.88.143)
I use them on my Infinity RSIIb speakers, which have planar mids and tweeters with PP cone woofers. They do a great job in delivering controlled, tight bass without being strident on the high notes. S .......
315: K&K Audio / Lundahl Transformers, RE: So Kevin, (0.00)
Posted by Maxamillion on 2012-07-09, 06:23:45 (206.228.220.37)
It turns out that you have a handy connection spot for the mu output on the compact cascode circuit board - the top pad designated for the optional fixed Rset resistor. I intend to try that versus the .......
316: K&K Audio / Lundahl Transformers, So Kevin, (0.00)
Posted by Maxamillion on 2012-07-09, 05:23:48 (206.228.222.37)
Have you tried both the mu and plate outputs on any of your constructions with your CCS? If so, which did you prefer and why? .......
317: K&K Audio / Lundahl Transformers, RE: K&K CCS Mu output - Sonic Tradeoffs? (0.00)
Posted by Maxamillion on 2012-07-08, 20:07:59 (206.228.220.39)
Back to the power supply modulation. Why spend all the time we do on PSUD simulating current steps, building well-regulated choke input supplies and making sure our power supplies don't ring or sag if .......
318: K&K Audio / Lundahl Transformers, RE: K&K CCS Mu output - Sonic Tradeoffs? (0.00)
Posted by Maxamillion on 2012-07-08, 20:02:26 (206.228.222.37)
Just use a diode in the cathode instead and the question goes away! .......
319: K&K Audio / Lundahl Transformers, RE: K&K CCS Mu output - Sonic Tradeoffs? (0.00)
Posted by Maxamillion on 2012-07-08, 18:56:05 (206.228.222.37)
That makes sense. Taking that a step further then, when you take the output from the plate you're actually taking the triode OUT of constant current operation, because you're using some of the current .......
320: K&K Audio / Lundahl Transformers, RE: K&K CCS Mu output - Sonic Tradeoffs? (0.00)
Posted by Maxamillion on 2012-07-08, 18:20:25 (206.228.222.37)
I've read that article from Gary but I always have the same reaction: doesn't all the current to drive ANY configuration come from the power supply? Where else would it come from? Why is the mu any di .......
321: K&K Audio / Lundahl Transformers, RE: K&K CCS Mu output - Sonic Tradeoffs? (0.00)
Posted by Maxamillion on 2012-07-08, 16:09:47 (206.228.222.37)
I've read that but I don't see how it's true, as there are still 2 mosfets between the mu output and the PSU. In any case, I'm also using a CCS-fed VR tube regulator (stacked VR150 + VR75 = 225V) so t .......
322: K&K Audio / Lundahl Transformers, K&K CCS Mu output - Sonic Tradeoffs? (0.00)
Posted by Maxamillion on 2012-07-08, 11:36:30 (206.228.220.37)
Hello, I'm in the final stages of pulling together a 26 tube preamp, Compact Cascode CCS plate loaded, LL1676 transformer coupled into a Slagleformer autoformer volume control on the output. I have th .......
323: Tube DIY Asylum, RE: I'm building a Preamp Now, and (0.00)
Posted by Maxamillion on 2012-04-16, 19:30:30 (206.228.220.39)
Since it's an autoformer VC following a stepdown transformer the output impedance will be low, until it gets into the boost region. For example, at -12dB it will be 31ohms, at -6dB it will be 125 ohms .......
324: Tube DIY Asylum, I'm building a Preamp Now, and (0.00)
Posted by Maxamillion on 2012-04-16, 06:48:17 (206.228.220.39)
I'm putting the attenuator at the output of the preamp. In that way, the attenuator will increase the signal/noise ratio of the system at volumes below wide open because it will attenuate the preamp's .......
325: K&K Audio / Lundahl Transformers, RE: LL1638, LL1673, or LL1685 - Which One? (0.00)
Posted by Maxamillion on 2012-03-08, 17:17:15 (166.137.139.118)
Thanks Kevin, That's very helpful info! .......
326: K&K Audio / Lundahl Transformers, RE: LL1638, LL1673, or LL1685 - Which One? (0.00)
Posted by Maxamillion on 2012-03-08, 15:48:56 (166.137.139.118)
It's really still a choke input supply with the first cap at only 0.44uF, hence the small c. Transformer secondary voltage is 350V, tube rectified using a 5U4GB. Are any considerations of the recommen .......
327: K&K Audio / Lundahl Transformers, LL1638, LL1673, or LL1685 - Which One? (0.00)
Posted by Maxamillion on 2012-03-08, 13:18:13 (206.228.220.39)
I'm working on a PSU for a 26 tube preamp. I want to use a cLCLC design followed by a CCS-VR tube combo running at a total DC draw of 52mA. Using PSUD-II, I find I can make an acceptable-looking PSU w .......
328: Tube DIY Asylum, And it Even Floats in Mid-Air (0.00)
Posted by Maxamillion on 2012-03-06, 09:02:26 (206.228.222.38)
Amazing stuff! .......
329: Tube DIY Asylum, Better to Use a CCS than Resistor (0.00)
Posted by Maxamillion on 2012-02-26, 07:42:55 (206.228.220.38)
Then you can set the CCS to the current consumed by the load + 20mA or so for the VR tube. No chance of blowing the VR tube this way, and the CCS gives excellent PSRR. .......
330: Vintage Asylum, Replace the Vellum Paper Behind the Faceplate (0.00)
Posted by Maxamillion on 2012-02-10, 12:25:28 (206.228.220.37)
The reason the color turns to green is that the Vellum paper that backs the faceplate turns yellow over time, and blue + yellow = green. I replaced the vellum paper and used the conventional lamp bulb .......
331: Tweakers' Asylum, Which Bybees?? (0.00)
Posted by Maxamillion on 2012-02-04, 06:02:44 (206.228.222.38)
The Music Rails or the "purifiers". I have measured the Music Rails and they do indeed work to reduce PS noise. I have not looked into the "purifiers" and therefore have no opinion on them but others .......
332: Vintage Asylum, What did you do with the Tube Electronics? (0.00)
Posted by Maxamillion on 2012-02-04, 05:53:59 (206.228.222.38)
If you have no use for them I'd be glad to take the amp. I just finished making a Grundig Majestic stereo tube amp into an iPod dock for my wife and now my son wants one! Here are the before and after .......
333: K&K Audio / Lundahl Transformers, RE: Applying DC Grid Bias Through LL1676 (0.00)
Posted by Maxamillion on 2012-01-15, 07:21:06 (206.228.220.38)
Hmmm...thorny issue. Perhaps using a transformer-based volume control will work better, but then there is no step-up, unless I use a transformer volume control with gain like a Sowter. Maybe a good qu .......
334: K&K Audio / Lundahl Transformers, Applying DC Grid Bias Through LL1676 (0.00)
Posted by Maxamillion on 2012-01-14, 22:18:31 (206.228.220.37)
I'm planning to use grid bias with a 9V alkaline battery for the 26 tube. I had an idea for eliminating the input coupling cap, and wanted a reality check, if that's OK. If I use an LL1676 input tran .......
335: K&K Audio / Lundahl Transformers, RE: Step Up Transformer for Preamp Input (0.00)
Posted by Maxamillion on 2012-01-12, 15:11:59 (166.137.139.161)
So if my source puts out 2V rms and I want to step that up by a factor of 2 the transformer will be putting out 4V rms - will the LL1544A be able to handle that? .......
336: K&K Audio / Lundahl Transformers, RE: Step Up Transformer for Preamp Input (0.00)
Posted by Maxamillion on 2012-01-12, 11:43:55 (206.228.220.39)
Thanks, Kevin. Is there a reason to prefer LL1676 over LL1544A or vice-versa? I notice one is called "High Level" and the other is "line level", does that matter in this application? .......
337: K&K Audio / Lundahl Transformers, Step Up Transformer for Preamp Input (0.00)
Posted by Maxamillion on 2012-01-12, 09:57:10 (206.228.220.37)
Hello all. I'm toying with the idea of building a 26 tube preamp to see how it compares with my 2C22 preamp. The 2C22 gives me (at full mu = 20) 14dB of voltage gain using a LL1674 output transformer .......
338: Tube DIY Asylum, RE: Update on Tube Amp i-Pod Docking Station (0.00)
Posted by Maxamillion on 2012-01-07, 05:11:55 (166.137.139.182)
Do you use the headphone output from the ipod? The line out from the Universal Dock should solve impedance mismatch issues without the need for a transformer. Output level is still lower than a CD pla .......
339: Tube DIY Asylum, Update on Tube Amp i-Pod Docking Station (0.00)
Posted by Maxamillion on 2012-01-04, 20:45:05 (206.228.220.37)
I posted back in November about my efforts to repurpose an old Grundig NF1 console amp into an i-Pod docking station for my wife. It's complete now and turned out very well. I ended up using an App .......
340: Tubes Asylum, ABSOLUTELY!! (0.00)
Posted by Maxamillion on 2012-01-04, 08:23:05 (206.228.222.37)
I have a pair that I have extensively modified, and I think they are the best-sounding speakers I've ever heard. Mine have external passive crossovers in separate boxes, new midrange diaphragms made b .......
341: Tweakers' Asylum, I prefer (2) OPA827 on Browndog Adapter (0.00)
Posted by Maxamillion on 2011-12-27, 19:36:48 (206.228.220.39)
to the OPA2134. I find they are more dynamic and have better bass performance, and having completely separate opamps eliminates the possibility of crosstalk between them. .......
342: Amp/Preamp Asylum, Did you ever try the Gilmore Raptor Monoblocks? (0.00)
Posted by Maxamillion on 2011-12-24, 09:16:52 (166.137.136.37)
The are based on the Icepower but incorporate proprietary input and output stages with no coupling caps, and massive linear supplies - they weigh 37lbs each due to the PS. They sound excellent on my b .......
343: Cable Asylum, I have these on my (0.00)
Posted by Maxamillion on 2011-12-23, 22:31:48 (206.228.222.37)
P5 Powerplant, CD player and Preamp. Use 83803 with Wattgate plugs - sounds good, but very stiff, so use right angle plugs in tight spots. .......
344: Tweakers' Asylum, RE: Mundorf Silver Oil outer foil (0.00)
Posted by Maxamillion on 2011-12-23, 19:27:48 (206.228.222.37)
I prefer to use my PC with True RTA spectrum analyzer instead of my oscilloscope for that job. Much easier to ID the outer foil by just watching the 60Hz peak while holding the cap between two fingers .......
345: Tweakers' Asylum, RE: I Prefer the Steward #28 Broadband Ferrite Material (0.00)
Posted by Maxamillion on 2011-12-22, 20:51:58 (206.228.222.37)
You'll need different ones depending upon what size wires you're putting them on. Measure the diameter of the wires you wish to treat and order the ferrites with the appropriate I.D. to match. You wan .......
346: Tweakers' Asylum, I Prefer the Steward #28 Broadband Ferrite Material (0.00)
Posted by Maxamillion on 2011-12-21, 23:04:02 (206.228.220.39)
Sold by Laird Technologies - Digikey stocks them. They have a very broadband absorption spectrum; unless you know specifically what frequencies you are after, you're better off with a broadband absorb .......
347: High Efficiency Speaker Asylum, The bottom pic looks like something (0.00)
Posted by Maxamillion on 2011-12-16, 21:13:50 (206.228.222.37)
the Whos in Whoville rode around in The Grinch. .......
348: Tweakers' Asylum, Never had a problem with WBT (0.00)
Posted by Maxamillion on 2011-12-14, 13:12:41 (206.228.222.37)
Also, I just did a heavier duty job with Stay-Brite Sn/Ag solder and a blowtorch to make some brackets for the amp I'm building. The Stay-Brite was OLD, but worked fine. Nasty acid flux on that stuff .......
349: Vintage Asylum, Nowadays I Look Like Clara Peller (0.00)
Posted by Maxamillion on 2011-12-14, 13:08:05 (206.228.222.37)
BOO!! .......
350: Tube DIY Asylum, I also posted it as a new thread (0.00)
Posted by Maxamillion on 2011-12-02, 09:27:34 (206.228.220.39)
in case it's of interest to others. .......
351: Tube DIY Asylum, How i-Pod Chargers Work with USB (0.00)
Posted by Maxamillion on 2011-12-02, 09:26:46 (206.228.220.39)
I'm building a tube docking station for my wife's i-Pod, and want to be able to charge the i-Pod while it's in the dock using power from an unused filament transformer tap, rectified and regulated of .......
352: Tube DIY Asylum, What's Going on in Newer iPod Charging (0.00)
Posted by Maxamillion on 2011-12-02, 08:49:57 (206.228.220.39)
Since you brought it up, here is a reference about what is needed to make newer iPods charge. It turns out they need certain voltages on the USB data pins to work, and that you can tailor the charging .......
353: Tubes Asylum, I agree on the 2C22 (0.00)
Posted by Maxamillion on 2011-11-23, 22:53:29 (206.228.222.37)
Put a CCS on the plate and 3.4V of SiC Schottky diode bias on the cathode, run it at ~14.5mA and 175V and the performers will float in front of you. .......
354: Tweakers' Asylum, Can you get that with a remote control? (0.00)
Posted by Maxamillion on 2011-11-23, 22:47:11 (206.228.222.37)
If so, I'd be interested for my preamp. .......
355: Tube DIY Asylum, RE: Working on a Tube iPod Docking Station (0.00)
Posted by Maxamillion on 2011-11-23, 12:34:03 (206.228.220.38)
OK, here's the scoop from Crosley themsleves. The AC21 cradle will NOT charge ipod Touch 2nd gen or newer, because the cradle uses the +12V Firewire pin to charge, and the ipod Touch 2nd gen and highe .......
356: Speaker Asylum, If You Really Want to Get Crazy... (0.00)
Posted by Maxamillion on 2011-11-22, 07:01:39 (206.228.222.38)
You could do what this guy in Italy did. His entire basement floor is a giant horn subwoofer! .......
357: Tweakers' Asylum, RE: How many colored Cardas Internal wire should I order for tweaked Magnepan MMGs? (0.00)
Posted by Maxamillion on 2011-11-19, 19:40:57 (206.228.222.37)
When I did my Infinity RSIIb's I did it all in black Cardas copper litz. 11.5ga on the woofers, 15.5ga on the mids, 17.5ga on the tweeters. I didn't see any need for different colors, if there is a qu .......
358: Tube DIY Asylum, RE: Working on a Tube iPod Docking Station (0.00)
Posted by Maxamillion on 2011-11-19, 18:59:23 (206.228.220.38)
Thanks. Planning to move the tubes up to the top plate to show off the nice glow, attach the docking cradle on the front between the volume and selector knobs (cool old cast metal knobs from a Zenith .......
359: Tube DIY Asylum, Working on a Tube iPod Docking Station (0.00)
Posted by Maxamillion on 2011-11-19, 08:27:46 (71.187.54.218)
for the wife. It will be based on guts from an old Grundig NF1 tube amp I scavenged from a free Grundig Majestic Console (gotta love free!). The amp makes 8.5WPC from ELL80s driven by 12AX7s, and the .......
360: Tube DIY Asylum, My measurements are for the CSD01060 (0.00)
Posted by Maxamillion on 2011-10-28, 23:04:28 (206.228.222.38)
1A SiC Shottky. .......
361: Tube DIY Asylum, If you look at the plot above (0.00)
Posted by Maxamillion on 2011-10-28, 05:54:53 (206.228.220.39)
in the region I run my 2C22 tubes (15 mA or so) the Rd is only ~1.7 ohm. Very low, indeed. .......
362: Tube DIY Asylum, See DanL post above for plot (0.00)
Posted by Maxamillion on 2011-10-27, 20:57:12 (206.228.220.38)
I measured them a couple years ago and posted it. .......
363: Tube DIY Asylum, That's My Excel Plot! (0.00)
Posted by Maxamillion on 2011-10-27, 20:50:20 (206.228.220.38)
Funny. I measured that and posted it a while back. What goes around comes around, I guess! .......
364: Tube DIY Asylum, RE: Diode bias for Cathode of 12ax7?? Latest diodesa// (0.00)
Posted by Maxamillion on 2011-10-26, 20:33:48 (206.228.220.38)
Cree Schottky diodes (1A) work great for me in my 2C22 based preamp. Far, far better than the stock resistor and cap. Each Cree will give you ~0.8V; you can stack em up like this: .......
365: Tube DIY Asylum, RE: I use these....... (0.00)
Posted by Maxamillion on 2011-10-11, 05:37:44 (206.228.222.38)
Hmmm...those silver plated beryllium copper ones look nice. I wonder if I could fit them into a larger ceramic cap? I'll have to check the measurements. Thanks for the tip! .......
366: Tube DIY Asylum, Those would be perfect if... (0.00)
Posted by Maxamillion on 2011-10-10, 16:15:09 (166.137.139.150)
They had wire entry from the side. I like the construction very much, and also the adjustability. I'll have to change the wires to make them longer if I use those. Thanks for the info - if they are th .......
367: Tube DIY Asylum, Best Quality Small Tube Top Caps (0.00)
Posted by Maxamillion on 2011-10-10, 11:23:32 (206.228.220.39)
I'm using 2C22 tubes in my Supratek preamp. These tubes have two 1/4" top caps each, for the anode and grid. I'm using the small ceramic top caps listed on the page linked below. The issue is that the .......
368: Vintage Asylum, RE: replacement power switch,etc for a marantz 2270 (0.00)
Posted by Maxamillion on 2011-10-03, 17:51:03 (166.137.138.168)
No, I went with the standard bayonet bulbs and new vellum paper behind the dial. Looks like new. Do a search on my name in the Marantz forum over on Audiokarma. I documented the rebuild of my 2230, wi .......
369: Vintage Asylum, RE: replacement power switch,etc for a marantz 2270 (0.00)
Posted by Maxamillion on 2011-10-03, 14:42:56 (206.228.220.39)
This is the power switch I used in my 2230. Fit just fine. .......
370: Tweakers' Asylum, RE: Hardly new, is it? (0.00)
Posted by Maxamillion on 2011-09-24, 13:53:51 (166.137.138.178)
I think the news is in regard to the magnitude of the effect. The HPM tweeters needed step up x-formers in the crossovers if I recall correctly. PS - I never could tell if those HPM tweeters worked or .......
371: Tweakers' Asylum, Move Over Crystals, Polymers can have 10X the piezoelectric effect (0.00)
Posted by Maxamillion on 2011-09-23, 10:56:11 (206.228.222.38)
Will this open the door for a new generation of polymer materials for tweakers? According to this note, the materials have 10X the reverse piezoelectric effect of crystals. Imagine the possibilities - .......
372: Tweakers' Asylum, RE: actually (0.00)
Posted by Maxamillion on 2011-09-14, 18:39:26 (166.137.138.220)
According to their datasheet, both the 2A and 15A parts have a very real voltage limit of 30V. You need to float the circuit with additional parts to go above 30V. There is also a block diagram in the .......
373: Tweakers' Asylum, RE: bybee music rails (0.00)
Posted by Maxamillion on 2011-09-12, 16:33:34 (166.137.136.166)
The Bybee name has been compromised somewhat by the "quantum" filters produced by Bybee previously, for which there is little evidence of efficacy. However, there is a fairly long thread on the Music .......
374: Tweakers' Asylum, RE: bybee music rails (0.00)
Posted by Maxamillion on 2011-09-10, 15:54:33 (166.205.140.145)
I've used the + and- 2 amp versions in the EQ unit for my Infinity RS2b speakers, installed following LM7818/7918 regulators. Scope measurements clearly showed a decrease in noise from the input to th .......
375: Tube DIY Asylum, Schematic is here (0.00)
Posted by Maxamillion on 2011-08-20, 20:59:25 (206.228.222.38)
. .......
376: Tube DIY Asylum, RE: Plate Choke VS. Cascode current source (0.00)
Posted by Maxamillion on 2011-08-20, 11:25:55 (166.137.138.249)
Differences were: much more focused, sharper imaging, much less "diffusion" of the sound, more and tighter bass (especially with Cree SiC schottky diode bias in the cathode), cleaner, clearer sound, m .......
377: Tube DIY Asylum, RE: Plate Choke VS. Cascode current source (0.00)
Posted by Maxamillion on 2011-08-19, 13:38:13 (206.228.220.37)
Not too hard to build one yourself. You don't even need a board. I wired up the cascoded IXYS 10M45S CCS on my preamp output tubes pin-to-pin, with the gate stoppers right at the pins as well. Slipped .......
378: Amp/Preamp Asylum, I don't know about amps, but Graphene intrigues me (0.00)
Posted by Maxamillion on 2011-08-01, 15:34:14 (206.228.220.39)
I think that graphene sheets would make an incredible ribbon driver. Only one atom thick, very conductive and extremely strong. Conductivity may be tailored via doping of the structure; reports are th .......
379: High Efficiency Speaker Asylum, Cardas Copper Litz (0.00)
Posted by Maxamillion on 2011-07-26, 12:49:24 (206.228.220.37)
I used Cardas teflon-insulated copper litz from Handmade Electronics to rewire my Infinity RSIIb speakers. I used 11.5ga on the woofers, 15.5ga on the mids and 17.5ga on the tweeters. They sound excel .......
380: Tube DIY Asylum, Source for SiC Schottky Diodes (0.00)
Posted by Maxamillion on 2011-07-26, 08:01:53 (206.228.220.37)
Digikey has them for $1 each. I use the 600V 1A version. .......
381: Tube DIY Asylum, RE: Diode Bias (0.00)
Posted by Maxamillion on 2011-07-26, 07:53:28 (206.228.220.37)
It sounds MUCH better than a resistor and cap. The diode functions as if it has a perfect bypass cap, with no high-pass filter effect, so the bass is greatly improved. Once I tried it there was no tur .......
382: Tube DIY Asylum, Diode Bias (0.00)
Posted by Maxamillion on 2011-07-26, 07:33:06 (206.228.222.38)
Instead of a resistor and cap, you use a fixed voltage drop diode. Some folks like to use LED's, but I prefer Cree silicon carbide schottky diodes as I feel they are less noisy. Each SiC Schottky is ~ .......
383: Tweakers' Asylum, RE: Giant Fat Gliders (0.00)
Posted by Maxamillion on 2011-07-26, 07:18:53 (206.228.222.38)
The Giant Fat Gliders did the trick with my Infinity RSIIb speakers. They decoupled the vibrations well, without losing the soundstage, and make these large speakers much easier to move around for pla .......
384: Tube DIY Asylum, RE: Best approach is to avoid cathode bypass caps like the plague (0.00)
Posted by Maxamillion on 2011-07-23, 09:50:07 (206.228.220.37)
When I went to Cree SiC schottky diode bias on my preamp the results were outstanding. Compared to a resistor and cap, well there is no comparison. Clearer, better bass, just overall better. ::: TOPIC .......
385: Tweakers' Asylum, Sounds Extremely Painful... (0.00)
Posted by Maxamillion on 2011-07-23, 09:46:55 (206.228.220.37)
Ouch! .......
386: Tube DIY Asylum, You could always build your own box. (0.00)
Posted by Maxamillion on 2011-06-18, 21:00:12 (206.228.222.38)
I made mine from MDF and oak veneer with a partition down the middle so I could put components on both sides, and the partition strengthens the box. For my Infinity RSIIb speakers. The upright style m .......
387: K&K Audio / Lundahl Transformers, Switched from CM to Standard Connection (0.00)
Posted by Maxamillion on 2011-05-26, 22:30:23 (206.228.222.38)
After a while with the second choke in the CM configuration, I rewired so that both chokes are in standard configuration and all three PS caps are star grounded to the same point as the PT center tap. .......
388: Tube DIY Asylum, RE: I heard a lot of good things about the Deuland caps. (0.00)
Posted by Maxamillion on 2011-05-10, 19:16:53 (206.228.222.38)
I have 1.0uF Duelund CAST caps in my Supratek Chenin preamp as DC blockers before the output transformers. They sound fantastic! They cost a small fortune, however, and they're huge. I feel that if yo .......
389: Tweakers' Asylum, RE: Heat is NOT light (0.00)
Posted by Maxamillion on 2011-05-03, 19:22:02 (206.228.220.39)
Conduction Convection Radiation 3 modes of heat transfer. .......
390: Cable Asylum, I use it in my System (0.00)
Posted by Maxamillion on 2011-04-21, 11:27:01 (206.228.222.38)
I made power cords with 83803 for my CD/HD player, preamp, and power regenerator. I think they sound great, and they look pretty cool with black Techflex braiding over the red teflon insulation and Wa .......
391: K&K Audio / Lundahl Transformers, RE: Results are in! (0.00)
Posted by Maxamillion on 2011-04-18, 09:18:40 (206.228.222.38)
For sure. Like I said, I have a cascoded CCS on the plates of the linestage tubes, and a shunt regulator using 350B tubes between the PS and the preamp, which should theoretically make the preamp circ .......
392: Amp/Preamp Asylum, RE: Supratek Chenin Preamp PS Mods (0.00)
Posted by Maxamillion on 2011-04-17, 19:27:05 (206.228.220.39)
Yes, I do love the Suprateks. This one had me up to 3:30am last night listening to music; the new supply really added authority to the lower end, startlingly so at times. .......
393: Amp/Preamp Asylum, Supratek Chenin Preamp PS Mods (0.00)
Posted by Maxamillion on 2011-04-16, 21:18:29 (206.228.222.38)
Thought you might like to see my latest Power Supply mod for my Chenin (phono and linestage). Stock it is a CLC with 33uF/10H/100uF. Caps were electrolytic. Last year I upgraded the caps to Solen f .......
394: K&K Audio / Lundahl Transformers, Results are in! (0.00)
Posted by Maxamillion on 2011-04-16, 20:38:47 (206.228.222.38)
And it sounds excellent! More body through the midrange, more bass slam (a LOT more), and smooth everywhere it should be. It even sounds a little smoother on top to boot. I have attached a picture .......
395: K&K Audio / Lundahl Transformers, RE: Question on Lundahl CMR connection (0.00)
Posted by Maxamillion on 2011-04-16, 11:37:20 (206.228.220.37)
I think I will go with choke #1 in standard hookup and choke #2 in CM hookup. This way I use the full series inductance of the first choke to block the ripple from the first (small) cap and get the CM .......
396: K&K Audio / Lundahl Transformers, Question on Lundahl CMR connection (0.00)
Posted by Maxamillion on 2011-04-06, 07:46:05 (206.228.220.37)
I am in the process of building a CLCLC power supply for my tube preamp. I am planning to try the CMR connection. Here is my question: Since this is CLCLC, with 10H LL1638 followed by 20H LL1673, shou .......
397: Tube DIY Asylum, RE: Have you tried the Lundahl CMR Connection? (0.00)
Posted by Maxamillion on 2011-04-06, 07:07:37 (206.228.220.37)
See the diagram at the bottom of the linked page. I'm going to try this in a power supply I'm building for my tube preamp, with CLCLC set up as: 6.8uF/10H LL1638/47uF/20H LL1673/100uF Should have nice .......
398: Tweakers' Asylum, There is a method to my madness (0.00)
Posted by Maxamillion on 2011-04-06, 05:48:08 (206.228.220.39)
OK, the reason for these experiments is that I have a very specific issue I would like to address, namely, some residual low level noise in an EQ unit for my speakers. The noise spectrum looks almost .......
399: Tube DIY Asylum, Have you tried the Lundahl CMR Connection? (0.00)
Posted by Maxamillion on 2011-04-05, 20:14:34 (206.228.222.37)
For their dual-coil chokes, they recommend putting one of the coils in the positive lead and one in the negative lead to form a common-mode choke to reduce CM noise. They claim that the choke otherwis .......
400: Tweakers' Asylum, Looking at the originals (0.00)
Posted by Maxamillion on 2011-04-05, 19:19:34 (206.228.220.39)
There is nothing I'd call a significant difference there - those plots are averages of 100 scans each, with some baseline noise present. .......
401: Tweakers' Asylum, I think you missed a key word in your post (0.00)
Posted by Maxamillion on 2011-04-05, 19:12:31 (206.228.220.39)
It makes no sense. .......
402: Tweakers' Asylum, RE: Question (0.00)
Posted by Maxamillion on 2011-04-05, 18:29:09 (206.228.220.39)
See the "validation" post below for a control experiment I ran using TI-Shield in the same setup. The patch cords are generic mic/RCA cords I use to connect my PC to a mic preamp when I do speaker re .......
403: Tweakers' Asylum, Additional Data for You, Jon, Validating the Measurement System (0.00)
Posted by Maxamillion on 2011-04-05, 18:23:46 (206.228.220.39)
In light of your questions, I repeated the same experiment tonight, but also tested a piece of TI-Shield instead of the bag of crystals. The first plot is the emission from the power supply with no sh .......
404: Tweakers' Asylum, RE: Does this correlate with what you hear? (0.00)
Posted by Maxamillion on 2011-04-05, 11:26:29 (206.228.220.38)
I completely disagree. It has been stated numerous times that this tweak is based on absorption and dissipation of emitted radiation by the crystals. It has also been stated that this can be measured .......
405: Tweakers' Asylum, Not Quite (0.00)
Posted by Maxamillion on 2011-04-05, 10:31:45 (206.228.220.37)
This is from Elizabeth's original post on the subject: "My test was fast just to see if my new pile of small crystal bits work. The Greenlee GT-16 non contact voltage detector (works great, highly rec .......
406: Tweakers' Asylum, RE: Do Crystals Work? The Experiment (0.00)
Posted by Maxamillion on 2011-04-05, 07:49:26 (206.228.222.38)
I tested the first 2% for two reasons: 1) That was the limit of the software I was using. 2) That range far exceeded the range of the Greenlee tester previously cited as evidence of an effect. If you .......
407: Tweakers' Asylum, Simple is often best (0.00)
Posted by Maxamillion on 2011-04-05, 06:07:05 (206.228.222.38)
To address the points: 1) The probe obviously picks up radiation when it is near to the power supply. When the power supply is removed, the radiation drops to the background level shown in my first pl .......
408: Tweakers' Asylum, RE: Do Crystals Work? The Results (0.00)
Posted by Maxamillion on 2011-04-04, 18:21:50 (206.228.222.37)
Below are the TrueRTA graphs from the experiment. The first is the background radiation in my workroom, the second is the emissions from the switching power supply being used as the signal source, the .......
409: Tweakers' Asylum, Do Crystals Work? The Experiment (0.00)
Posted by Maxamillion on 2011-04-04, 17:50:28 (206.228.222.37)
After reading all the posts here about crystals and their effects, I decided to do a little experiment to see if I could measure what they were doing. I went to Michaels craft store and purchased a fe .......
410: K&K Audio / Lundahl Transformers, RE: Tell me about the LL1673AM for a PS Choke (0.00)
Posted by Maxamillion on 2011-03-31, 12:27:26 (206.228.220.37)
I was afraid you would say that. I too hear differences in my preamp when I make PS changes, even though it has a tube shunt regulator and cascoded CCS. Bypassing the PP PS caps with small value oil c .......
411: K&K Audio / Lundahl Transformers, Tell me about the LL1673AM for a PS Choke (0.00)
Posted by Maxamillion on 2011-03-31, 06:31:32 (206.228.222.37)
What are the advantages of the amorphous iron core for a PS application where there is no signal passing through the choke (and using CCS on tube plates for high PS rejection)? Does the amorphous core .......
412: K&K Audio / Lundahl Transformers, RE: LL1673 Choke in CMR mode - Audible Difference? (0.00)
Posted by Maxamillion on 2011-03-30, 20:10:12 (206.228.222.38)
Thanks! That's exactly the kind of info I was looking for. .......
413: K&K Audio / Lundahl Transformers, LL1673 Choke in CMR mode - Audible Difference? (0.00)
Posted by Maxamillion on 2011-03-30, 11:18:51 (206.228.222.38)
Was wondering if anyone has tried the LL1673 choke in the typical series and Common Mode Rejection (CMR) series configurations in a CLC supply for a preamp, and what their impressions were. I'm consid .......
414: Tweakers' Asylum, What Shakti Used for Damping Quartz Crystals (0.00)
Posted by Maxamillion on 2011-03-25, 13:58:26 (206.228.220.38)
The patent recommends a viscoelastic damping compound made by DAP. If you believe the trial and error research used herein, then it is likely that the ideal treatment would be with a similarly viscoel .......
415: Tweakers' Asylum, Well, there is this version with pictures (0.00)
Posted by Maxamillion on 2011-03-25, 08:54:13 (206.228.222.37)
of how I built my RC speaker filters. I think they came out very nice and they work great. .......
416: Cable Asylum, Power Regeneration (0.00)
Posted by Maxamillion on 2011-03-21, 05:50:26 (206.228.220.39)
If the stereo sounds better in the late evening, then it sounds like your power is being distorted by demand from others at the other times. A power regenerator can help with that. I have a PS Audio P .......
417: Cable Asylum, Start with a dedicated line (0.00)
Posted by Maxamillion on 2011-03-19, 18:57:13 (206.228.220.38)
Run at least one dedicated 20 amp line from the fuse box directly to an outlet for your gear. Use at least a good quality hospital-grade outlet. Nothing will be connected to this line other than your .......
418: Speaker Asylum, Only on the low end (0.00)
Posted by Maxamillion on 2011-03-16, 08:40:14 (206.228.220.39)
Solens on the woofer shunt and low midrange (up to 800Hz). Mundorf Supreme bypassed with Audicap Theta on everything 800Hz and up. The woofer shunt is 200uF and the low mid series cap is 70uF, not a l .......
419: Tube DIY Asylum, More close-up view (0.00)
Posted by Maxamillion on 2011-03-16, 08:31:16 (206.228.220.39)
With and without Techflex: .......
420: Tube DIY Asylum, RE: Wire for external crossover? (0.00)
Posted by Maxamillion on 2011-03-16, 08:26:28 (206.228.220.39)
I used three different gauges of wire for the connections to my external crossovers, all of it Cardas Teflon-insulated Copper Litz. I used 11.5ga on the woofers, 15.5ga on the midranges, and 17.5ga .......
421: Speaker Asylum, Something like this ought to have Plenty of Room (0.00)
Posted by Maxamillion on 2011-03-15, 12:40:40 (206.228.222.37)
for my Infinity RSIIb's: .......
422: Tube DIY Asylum, Not Hundreds, Just a few (0.00)
Posted by Maxamillion on 2011-03-14, 05:53:42 (206.228.220.38)
The Cree SiC Schottky's are about .86V per diode due to the higher bandgap of SiC versus Si. I use 4 to get 3.4V bias on my 2C22 preamp at 14.6mA, 175V plate. They stack very nicely against each other .......
423: Tube DIY Asylum, RE: Mike, is that the Solen PB series? (0.00)
Posted by Maxamillion on 2011-03-08, 22:04:39 (76.8.81.150)
I use the 200uF Solens in the outboard crossovers for my Infinity RSIIb's (the big caps at the bottom left). They work very well there. .......
424: Tweakers' Asylum, RE: Yea but... (0.00)
Posted by Maxamillion on 2011-03-06, 14:59:37 (206.228.220.38)
I have found that for me it's easier to see the difference with the RTA, but you should be able to use the scope as well. Do exactly what I said except with the scope instead of the RTA, and look for .......
425: Tweakers' Asylum, RE: How... (0.00)
Posted by Maxamillion on 2011-03-06, 14:10:31 (206.228.222.38)
Like I said, I use TrueRTA spectrum analyzer software on my laptop. I plug a cable into the mic input and then use the other end of the cable to test the caps, with the averaging value set to 1 and th .......
426: Tweakers' Asylum, The difference is easily measured (0.00)
Posted by Maxamillion on 2011-03-06, 10:05:38 (206.228.222.38)
as I posted above. Up to 10dB difference between orientations. That can add up when you think about having a number of caps in the circuit. I guess it depends on your priorities. If you value having .......
427: Tweakers' Asylum, I Have Just Checked 16 of the PPMFX 0.1uF (0.00)
Posted by Maxamillion on 2011-03-04, 20:35:30 (206.228.220.39)
for use in my tube preamp as heater snubbers. There is NO consistency in their outer and inner foil end markings. There IS, however, a substantial difference in noise between the correct (outer foil t .......
428: Tweakers' Asylum, RE: I found a 6dB Difference on those caps (0.00)
Posted by Maxamillion on 2011-02-19, 08:22:02 (206.228.220.37)
I tried using my 20MHz scope but I seem to get a more definitive result with the RTA - just my personal observation. I also like that I can save and overlay the graphs on the RTA for comparison purpos .......
429: Tubes Asylum, Valve Art 350B Heater Current (0.00)
Posted by Maxamillion on 2011-02-18, 10:10:12 (206.228.220.37)
I know the heater current of the WE 350B is listed as 1.6A, but does anyone know if the Valve Art is the same? I know that sometimes these knockoff tubes don't match up in all the specs (sometimes the .......
430: Tweakers' Asylum, I found a 6dB Difference on those caps (0.00)
Posted by Maxamillion on 2011-02-18, 07:48:36 (206.228.220.37)
Outer foil correctly connected gave 6dB less noise than the other way around, using TrueRTA on my PC. I have found this method to be ideal for determining outer foil: Simply set the RTA software to sp .......
431: Tubes Asylum, Don't forget rectifiers and regulators and... (0.00)
Posted by Maxamillion on 2011-02-16, 10:23:46 (206.228.220.39)
Don't forget rectifier tubes and regulator tubes, they can also alter the sound by changing the operating points of the other tubes. Then you have coupling and power supply capacitors, often noted to .......
432: Speaker Asylum, Remember to reverse that (0.00)
Posted by Maxamillion on 2011-02-11, 05:38:24 (206.228.220.38)
if you are in the Southern Hemisphere. .......
433: Tweakers' Asylum, What is the mechanism? (0.00)
Posted by Maxamillion on 2011-02-10, 12:03:33 (206.228.222.37)
What is happening to cause the CDs to interact with your player and preamp? .......
434: Tweakers' Asylum, Funny Thing, Al, Those Diodes (0.00)
Posted by Maxamillion on 2011-02-10, 06:06:15 (206.228.220.38)
are Cree SiC Schottky's, which have zero reverse recovery charge. I did a lot of hunting around the circuit looking for noise using a RTA spectrum analyzer and a grounded piece of TI-Shield, and by fa .......
435: Tweakers' Asylum, You need to ground the shield (0.00)
Posted by Maxamillion on 2011-02-10, 05:48:21 (206.228.220.38)
Nice try, though. .......
436: Tweakers' Asylum, Bad Day? (0.00)
Posted by Maxamillion on 2011-02-09, 09:44:15 (206.228.220.38)
Thanks for trolling my thread. Of course I understand that caps are used as snubbers, I use them all the time, and that's what the filter I discussed is based on. I was just pointing out that they can .......
437: Tweakers' Asylum, That will just radiate the noise (0.00)
Posted by Maxamillion on 2011-02-09, 06:16:13 (206.228.222.38)
out into the room, probably better off keeping it in the wall! I have found that caps subjected to AC are huge noise polluters. In another project I built a shield for the inside of the EQ unit that c .......
438: Tweakers' Asylum, 6 days later - Nice (0.00)
Posted by Maxamillion on 2011-02-08, 21:07:58 (206.228.222.38)
For whatever reason, it seems like there is a bit of breakin to these things. Day six and the system sounds excellent. Well worth the effort. .......
439: Amp/Preamp Asylum, Class D might be the ticket (0.00)
Posted by Maxamillion on 2011-02-08, 06:01:30 (206.228.220.37)
If it's just for subwoofer duty, get a pair of class D monos - plenty of power, low power consumption, run cool, can be left on 24/7, etc. There are lots of choices in class D today, like NuForce, Wir .......
440: Tweakers' Asylum, RE: Ah experimentation! (0.00)
Posted by Maxamillion on 2011-02-06, 12:11:46 (206.228.220.37)
Yeah, I certainly wasn't expecting it to sound worse, either, but it did. Maybe it was the fact the I switched the socket for the PPP to the never-used top one of the duplex pair - I needed the bottom .......
441: Tweakers' Asylum, My DIY AC Line Filter Build (0.00)
Posted by Maxamillion on 2011-02-06, 11:19:56 (206.228.220.37)
I decided to build a parallel AC line filter along the lines of the ones outlined here, with a couple twists. First step was to determine the values of the components needed. Since I wanted to termina .......
442: Tweakers' Asylum, RE: My thought is probably a lost cause... (0.00)
Posted by Maxamillion on 2011-02-03, 20:52:15 (206.228.220.37)
Guess that would depend on how badly the line is polluted now. The wire to my EQ is unshielded and runs past the back of a CRT projection TV, a cable box with DVR, and several 120V power cords, so the .......
443: Tweakers' Asylum, RCR Filter on EQ Power Inlet - WOW (0.00)
Posted by Maxamillion on 2011-02-02, 09:50:13 (206.228.220.37)
Hello all. In my continuous obsessive quest for perfection I have done major upgrades to many parts of my system, but this one may be the best bang for the buck of all. I installed an RCR filter betwe .......
444: Tweakers' Asylum, Funny Thing about Opamps (0.00)
Posted by Maxamillion on 2011-01-29, 22:41:32 (206.228.220.38)
When I was looking to upgrade the sound of the Infinity-supplied equalizer that goes with my RSIIb speakers, I ended up clipping out the single-ended MOSFET output buffer stage (fed by a MOSFET CCS .......
445: Tweakers' Asylum, Update - Signal Path Ferrites (0.00)
Posted by Maxamillion on 2011-01-22, 22:58:25 (206.228.220.38)
= BAD. I was going to put some ferrite beads (Steward #28, leaded, PN 28L0138-40R-10) on the grid pin of my preamp tubes, but since the grid is on a top cap it would have required some butchery of the .......
446: Tweakers' Asylum, RE: Where do you buy the ferrites? (nt) (0.00)
Posted by Maxamillion on 2011-01-21, 19:44:46 (206.228.222.38)
Digikey. I recommend the Steward #28 material; it has a very broadband effect, and works better than the Radio Shack ferrites I tried at first. .......
447: Tweakers' Asylum, RE: filament supplies (0.00)
Posted by Maxamillion on 2011-01-21, 19:42:07 (206.228.222.38)
Interesting about the filament and cathode ripple. I don't really have an issue with hiss, I'm talking about a level most wouldn't even notice. Previously, it was barely noticeable with my ear right .......
448: Tweakers' Asylum, RE: Here is the URL of the RC Filter Construction, if you are interested (0.00)
Posted by Maxamillion on 2011-01-21, 11:25:43 (206.228.220.39)
Yes, a very big difference (sorry). I have replaced all the electrolytics with film caps: Solen on the woofer, Solen bypassed with Mundorf Supreme on the low mids, Mundorf Supreme bypassed with Duelun .......
449: Tweakers' Asylum, RE: Here is the URL of the RC Filter Construction, if you are interested (0.00)
Posted by Maxamillion on 2011-01-21, 07:57:06 (206.228.220.39)
Here are mine, with the outboard crossovers I built for them. I have brand new EMIM diaphragms from Apogee Acoustics in Australia - the new diaphragms are MUCH better than the stock units in terms of .......
450: Tweakers' Asylum, RE: Here is the URL of the RC Filter Construction, if you are interested (0.00)
Posted by Maxamillion on 2011-01-20, 20:51:41 (206.228.220.37)
It's a 4 ohm speaker system, Infinity RSIIb. .......
451: Tweakers' Asylum, Here is the URL of the RC Filter Construction, if you are interested (0.00)
Posted by Maxamillion on 2011-01-20, 09:49:52 (206.228.222.38)
http://db.audioasylum.com/mhtml/m.html?forum=tweaks&n=170067 .......
452: Tweakers' Asylum, RE: My Adventures with Ferrite Clamps (0.00)
Posted by Maxamillion on 2011-01-20, 09:41:34 (206.228.222.38)
I actually have RC filters on both ends of my Zu Ibis speaker cables. I made them using cascaded silver mica caps and TX2575 metal foil resistors, shielded with TI-Shield in a potted ABS box. I select .......
453: Tweakers' Asylum, RE: My Adventures with Ferrite Clamps (0.00)
Posted by Maxamillion on 2011-01-20, 06:16:07 (206.228.220.39)
Being a scientist myself, I tend to do my experiments with some rigor, although with the wife away this week double blind testing was not possible. I used big .35 and .50" ferrites on the Romex and th .......
454: Tweakers' Asylum, RE: My Adventures with Ferrite Clamps (0.00)
Posted by Maxamillion on 2011-01-19, 21:15:43 (206.228.220.38)
Thanks. I have one 20 amp dedicated line feeding my entire system, with 12/2 Romex wire. Two cryoed Hubble duplex outlets are fed by the single dedicated line. The Supratek preamp results were surpris .......
455: Tubes Asylum, My Favorite 6SN7 is a 7193! (0.00)
Posted by Maxamillion on 2011-01-17, 06:24:48 (206.228.220.39)
I got fed up wth 6SN7s in my Supratek Chenin (Chardonnay with phono stage) and converted it to run single triode 7193 (2C22), one per channel. Way, way better sounding than any 6SN7 I tried, and I .......
456: Tweakers' Asylum, My Adventures with Ferrite Clamps (0.00)
Posted by Maxamillion on 2011-01-15, 17:48:42 (206.228.222.37)
I've been experimenting with ferrite clamps on power lines, and I've come to a few conclusions. I'll list them in terms of the application: 1) On power lines of other appliances - GOOD. I bought a bun .......
457: Tweakers' Asylum, OPA827 (0.00)
Posted by Maxamillion on 2011-01-14, 10:06:16 (206.228.222.37)
Another JFET input opamp to consider is the OPA827. Two of those on a Browndog adapter sound terrific! I compared them to the LF353, OPA2134 and the OPA2107, and the 827s were clearly better than all .......
458: Tweakers' Asylum, RCA Shorting Plug works too (0.00)
Posted by Maxamillion on 2011-01-10, 10:13:23 (206.228.222.38)
You can do a similar thing with a shorting plug in the RCA jack. I have actually measured the effect using a spectrum analyzer and it is quite apparent, especially if you have your gear in a noisy env .......
459: Tweakers' Asylum, It's all about prevention of contamination (0.00)
Posted by Maxamillion on 2011-01-10, 09:58:53 (206.228.222.38)
I'm still experimenting with the ferrites on the cables of my stereo system, but putting them on all the other power cables in the house is a no brainer to me based on their low cost. Even better than .......
460: Tweakers' Asylum, Ferrites Rule! (0.00)
Posted by Maxamillion on 2011-01-09, 20:32:50 (206.228.222.37)
Don't knock ferrites. Ferrite clamps are excellent RFI chokes and absorbers, and at $1-2 each they are a great value as well. I have them on the power cords of every appliance in my home, and on the R .......
461: Tubes Asylum, RE: Why are the most popular tubes often dismissed as bad choices. (0.00)
Posted by Maxamillion on 2010-12-06, 19:00:21 (206.228.220.39)
Sometimes you can get by with just (1) 2C22 to replace a 6SN7, especially if you use a CCS on the plate. It took my Supratek from "way too much gain" to "just right!" .......
462: Tweakers' Asylum, Here's a Tweak for those Rectifier and Cap Stray Fields (0.00)
Posted by Maxamillion on 2010-11-04, 09:19:20 (206.228.220.37)
Here's what I did with the low frequency EQ unit for my Infinity RSIIb speakers. I built a shield of TI-Shield material around the rectifier filter caps, rectifiers and regulators, grounded to the .......
463: Vintage Asylum, RE: Older speakers vs. New speaker technology (0.00)
Posted by Maxamillion on 2010-10-14, 12:08:24 (206.228.222.37)
Electromagnetic Induction Midrange = EMIM Electromagnetic Induction Tweeter = EMIT Basicaly planar magnetic mids and tweeters. .......
464: Amp/Preamp Asylum, RE: Solid State Power: MOSFET vs. Bipolar? (0.00)
Posted by Maxamillion on 2010-10-14, 06:22:49 (206.228.222.37)
You know, I felt the same way until I recently made some changes to the low frequency EQ/buffer unit on my Infinity RSIIb speakers. I wanted to get rid of the output coupling caps so I changed the sin .......
465: Vintage Asylum, RE: Older speakers vs. New speaker technology (0.00)
Posted by Maxamillion on 2010-10-13, 13:05:11 (206.228.222.37)
Love my Infinity RSIIb's! 4 10" woofers plus EMIM mids and EMIT tweeters do the trick for me. Oh yeah, and the new outboard crossovers and Apogee-made EMIM diaphragms help a lot too! .......
466: Vintage Asylum, RE: EPI T/E 100 (0.00)
Posted by Maxamillion on 2010-09-16, 16:05:12 (206.228.220.38)
He can always throw a resistor in the circuit to simulate the ESR of the electro. Dial it in with a small pot to taste and then sub in a resistor. .......
467: Speaker Asylum, My Infinity RSIIb's (0.00)
Posted by Maxamillion on 2010-09-12, 14:25:38 (206.228.220.39)
With my homemade outboard passive crossovers in the boxes behind them, and brand new EMIM diaphragms from Apogee Acoustics in Australia. .......
468: Tweakers' Asylum, RE: Opinions of NOS Jensen PIO at PCX? (0.00)
Posted by Maxamillion on 2010-09-10, 05:54:36 (206.228.222.38)
That's an idea, but those caps are 0.5% tolerance - not likely to be a 9000pF cap in there. They are also too big to fit where I need them to go. .......
469: Tweakers' Asylum, Opinions of NOS Jensen PIO at PCX? (0.00)
Posted by Maxamillion on 2010-09-07, 12:30:03 (206.228.220.38)
I'm looking to warm up the sound of an EQ unit I'm using. In the signal path is a 0.018uF polystyrene (styroflex-type) cap. That value is hard to find, but PCX has some NOS PIO caps on sale in exactly .......
470: Vintage Asylum, RE: Deeper bass for 890c Boleros?? (0.00)
Posted by Maxamillion on 2010-09-05, 13:04:28 (206.228.222.38)
I'll trade you those very same Advents for the Boleros! And I'll throw in my stick figure sketch of Michael Jackson...;-) .......
471: K&K Audio / Lundahl Transformers, Here's what I ended up doing (0.00)
Posted by Maxamillion on 2010-09-03, 12:42:20 (206.228.220.37)
Just to tie this thread up. I ended up building a new unity gain output buffer stage using an OPA827 opamps. The very low DC offset of the 827 allowed me to go without any coupling cap or transformer! .......
472: K&K Audio / Lundahl Transformers, RE: An Alternative to LL1671? (0.00)
Posted by Maxamillion on 2010-08-21, 15:52:02 (206.228.220.39)
Thanks for the advice. The source follower MOSFET already has a CCS to set the idle current to 25-30mA. Here is the circuit schematic: Why they put that huge coupling cap in there is beyond me, bu .......
473: K&K Audio / Lundahl Transformers, RE: An Alternative to LL1671? (0.00)
Posted by Maxamillion on 2010-08-21, 07:14:27 (206.228.220.38)
Well, all the formulas I've seen for calculating parafeed cap size have the source resistance in the denominator, so I'm thinking that having such a low source resistance may require an enormous cap. .......
474: Tube DIY Asylum, Forward Voltage Drop vs Current (0.00)
Posted by Maxamillion on 2010-08-20, 22:57:30 (206.228.220.39)
Here is a graph I drew up from my experimental results with the 1A 600V Cree SiC Schottkys. .......
475: K&K Audio / Lundahl Transformers, An Alternative to LL1671? (0.00)
Posted by Maxamillion on 2010-08-20, 20:03:28 (206.228.222.37)
The LL1671 sounds appropriate for this application due to the DC present from the single-ended MOSFET. However, I am hooked on the sound of the amorphous core Lundahls, so I'm thinking that the LL1684 .......
476: K&K Audio / Lundahl Transformers, RE: Replacing Output Caps with Transformers (0.00)
Posted by Maxamillion on 2010-08-19, 19:10:39 (206.228.220.37)
Hmmm. Very nice. I need to think this through a bit more, but it sounds like the 1671PP would work quite nicely, and it should just fit in the box. Thanks, Kevin! .......
477: K&K Audio / Lundahl Transformers, RE: Replacing Output Caps with Transformers (0.00)
Posted by Maxamillion on 2010-08-19, 13:21:35 (206.228.222.37)
Well, the transformer would be fed by a MOSFET source follower using VN40AD MOSFETS. That should have an output impedance of ~3ohms, much much lower than any tube. The following stage has an input imp .......
478: K&K Audio / Lundahl Transformers, Replacing Output Caps with Transformers (0.00)
Posted by Maxamillion on 2010-08-18, 13:49:15 (206.228.222.37)
I've installed the LL1674 as output x-formers in my preamp, to great effect, and now I'm thinking about the new weak link in the audio chain, the low frequency equalizer that Infinity supplied with my .......
479: Tweakers' Asylum, RE: Is there any danger (0.00)
Posted by Maxamillion on 2010-08-18, 09:07:41 (206.228.220.38)
Sure, if you apply too much pressure with the Dremel and hold it there too long. Like any technique, if done improperly you may have issues. In my experience, I found this technique far faster, cleane .......
480: Tweakers' Asylum, Dremel is the Best Way I have found (0.00)
Posted by Maxamillion on 2010-08-18, 07:38:18 (206.228.220.39)
I just built an outboard crossover for my Infinity RSIIb speakers using Cardas copper litz wire, in 17.5, 15.5 and 11.5 gauges (total gauge, individual wires much thinner). I tried all the methods men .......
481: General Asylum, RE: How about EMITs? (0.00)
Posted by Maxamillion on 2010-08-15, 18:07:57 (206.228.222.37)
Many of the standard EMITs use the same diaphragm, #3722. Exceptions include the EMIT-K, EMIT-R, and the very old EMIT. You can swap out a diaphragm from many other EMITs into your EMIT's shell and it .......
482: General Asylum, Reviews from users of the new EMIM diaphragms (0.00)
Posted by Maxamillion on 2010-08-14, 21:08:29 (206.228.220.37)
Here is a link to a thread at AudioKarma containing user impressions of the new EMIM diaphragms from Apogee. So far everyone who has tried them loves them - some buy a complete set at once (like me!), .......
483: General Asylum, Apogee Acoustics in Australia IS Making them!! (0.00)
Posted by Maxamillion on 2010-08-14, 21:00:07 (206.228.220.38)
And they are far, far superior to the originals. Graz at Apogee is a master, and his replacements are true ribbons, designed to fit perfectly and to sound much better. I have a set in my RSIIb speaker .......
484: Tube DIY Asylum, RE: Any reason for using HV cree antenna's on the Cathode... (0.00)
Posted by Maxamillion on 2010-08-11, 05:49:33 (206.228.222.38)
The main reason I used them is that I had some on hand from a previous project where I was using them in a rectifier. The SiC has a higher forward voltage than a standard Schottky (~.86V vs ~.3V) so I .......
485: Tube DIY Asylum, RE: CCS plate load on a grounded cathode preamp (0.00)
Posted by Maxamillion on 2010-08-10, 12:18:03 (206.228.220.39)
For a diode, the forward voltage drop is consistent over a wide range of currents, unlike a resistor (diodes don't follow Ohms Law). Less important with a CCS as the current is being held relatively c .......
486: Tube DIY Asylum, RE: CCS plate load on a grounded cathode preamp (0.00)
Posted by Maxamillion on 2010-08-09, 12:30:43 (206.228.220.37)
I added the cascoded IXYS 10M45S CCS to my 2C22 preamp, and instead of a cathode resistor I used diode bias on the cathode. I use Cree SiC Schottky diodes, stacked to reach the desired bias value (a d .......
487: Tweakers' Asylum, Texas Components (0.00)
Posted by Maxamillion on 2010-08-09, 10:43:12 (206.228.220.39)
The Texas Components TX2575 is my favorite. $9.40 each for 0.1% tolerance right here: http://www.texascomponents.com/pdf/tx2575.pdf Just call or email them and they will sell direct to you with no min .......
488: K&K Audio / Lundahl Transformers, Measurements, Schmeasurements - these things sound Great! (0.00)
Posted by Maxamillion on 2010-08-08, 12:00:15 (166.216.130.26)
Thanks for the explanation, Kevin. I have everything back together with the snubber in place and the transformer wired 4:1, and the LL1674s sound excellent! They are clearly superior to the stock tran .......
489: K&K Audio / Lundahl Transformers, RE: OK, so I tried (0.00)
Posted by Maxamillion on 2010-07-31, 19:49:29 (206.228.220.39)
Yes. I tried the 22 ohm resistors and also a 500 ohm pot in series with both the primary and secondary, on both ends and in the middle - no effect on the ringing at any setting. I tried grid, plate an .......
490: Amp/Preamp Asylum, Duelund CAST (0.00)
Posted by Maxamillion on 2010-07-31, 13:33:04 (206.228.220.39)
Should be on that list. Expensive, yes, but they made a huge improvement in the sound of my tube preamp. Detailed yet warm and involving. I'm using them as the Parafeed coupling cap. Think about it th .......
491: K&K Audio / Lundahl Transformers, No DC on the Transformer (0.00)
Posted by Maxamillion on 2010-07-31, 08:04:47 (206.228.220.38)
No, definitely NOT running any DC through the transformer. I was talking about the AC signal current - the DC current is blocked by the parafeed cap on the + side of the circuit. I'm grasping for answ .......
492: K&K Audio / Lundahl Transformers, OK, so I tried (0.00)
Posted by Maxamillion on 2010-07-30, 20:22:03 (206.228.220.38)
plate stoppers (0 to 500 ohm) = no effect on ringing stoppers at the end of the CCS (0 to 500 ohm) = no effect on ringing I was seeing the ringing at the plate when the transformer was in the circuit, .......
493: K&K Audio / Lundahl Transformers, RE: LL1674 Snubber Circuit and Question (0.00)
Posted by Maxamillion on 2010-07-29, 19:23:38 (206.228.222.37)
I tried 1k grid stoppers and they had no effect on the ringing. I also have a 1k Mills anode stopper on the CCS. I suspect that there is something about the CCS, the high tube current and the transfor .......
494: K&K Audio / Lundahl Transformers, RE: LL1674 Snubber Circuit and Question (0.00)
Posted by Maxamillion on 2010-07-29, 11:19:31 (206.228.220.37)
Well, I have 1k carbon comp gate stoppers on all the gates, and the ringing is very low in frequency (11kHz) to be from the CCS, but I guess it's possible. I'll be looking into that and the effect of .......
495: K&K Audio / Lundahl Transformers, RE: LL1674 Snubber Circuit and Question (0.00)
Posted by Maxamillion on 2010-07-28, 19:50:32 (206.228.220.39)
Upon further investigation, it seems that both the transformer and the tubes may be contributing to the ringing, as I see some at the tube anode as well. I will need to do some further work to pin thi .......
496: K&K Audio / Lundahl Transformers, RE: LL1674 Snubber Circuit and Question (0.00)
Posted by Maxamillion on 2010-07-27, 08:45:57 (206.228.220.39)
Here is a comparison of the preamp with the stock transformer (green) versus the LL1674 (right and left channels), in the 11kHz region. The LL1674 is either the cause of the dip or it is revealing som .......
497: K&K Audio / Lundahl Transformers, RE: LL1674 Snubber Circuit and Question (0.00)
Posted by Maxamillion on 2010-07-27, 06:31:31 (206.228.220.38)
I did listen before and after the snubber and the result is very good - it sounds like it does with the optimal resistor loading but with more gain and better bass response (pretty much what the squar .......
498: K&K Audio / Lundahl Transformers, LL1674 Snubber Circuit and Question (0.00)
Posted by Maxamillion on 2010-07-25, 07:03:15 (206.228.222.37)
Hello all, I have installed an LL1674 as a 4:1 output transformer in my 2C22 single-ended preamp output stage, and I ran into some HF ringing issues, so I tried resistor loading the transformer second .......
499: K&K Audio / Lundahl Transformers, RE: Question re: Resistor Loading of LL1674 (0.00)
Posted by Maxamillion on 2010-07-20, 07:56:05 (206.228.220.38)
Thanks, Kevin. There is a nice PIO cap to block the DC. I'll do without the resistors then. .......
500: K&K Audio / Lundahl Transformers, Question re: Resistor Loading of LL1674 (0.00)
Posted by Maxamillion on 2010-07-20, 05:23:33 (206.228.220.37)
Hello, I'm in the process of modifying my preamp to use the LL1674 output transformer in place of the stock unit, which is a small power toroid (115V+115V, 22V+22V, .08VA+0.8VA) wired as a 4:1 stepdow .......
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