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1: Tube DIY Asylum, RE: Drummerwill is just ONE resistor away ...... (0.00)
Posted by PeterP on 2012-10-18, 18:51:58 (74.105.105.3)
Now that’s evolution in the right direction. Absolutely stunning. A beautiful example of “form follows function”. Enjoy. .......
2: Tube DIY Asylum, OT - My Accidental Speaker. (0.00)
Posted by PeterP on 2012-10-03, 09:14:04 (74.105.105.3)
I wanted some small speakers to use with my PC. So I ordered a few to try out. One of these was the Peerless 830987 3” Full Range speaker. First it’s really a 2-1/2” but that’s OK by me. When they arr .......
3: Tube DIY Asylum, RE: There is no such thing as a combo start/run cap. The cap in Q is a run cap..... (0.00)
Posted by PeterP on 2011-01-19, 09:34:31 (74.105.110.60)
As long as it's clearly marked a such you are quite right. I just remember some "combo" caps from the early '70s that were used in some military equipment. (Maybe they were custom just for that specif .......
4: Tube DIY Asylum, RE: Careful!!! (0.00)
Posted by PeterP on 2011-01-19, 04:51:32 (74.105.110.60)
Double check the part that you are using. There are combination Motor Start/Run caps. These typically have two capacitors. One (Higher value) to start the motor and a second one as the Motor Run cap. .......
5: Tube DIY Asylum, RE: 2w SE amp speaker choice help - OOPS (0.00)
Posted by PeterP on 2010-04-22, 12:50:17 (74.105.99.250)
Try this link http://cid-e7c985f306a17207.skydrive.live.com/browse.aspx/.Public/MD%20Pics .......
6: Tube DIY Asylum, RE: 2w SE amp speaker choice help (0.00)
Posted by PeterP on 2010-04-22, 12:44:57 (74.105.99.250)
The 6T9 amp is really a compactron with triode input and I'm running a UL output. Check out. http://cid-e7c985f306a17207.skydrive.live.com/browse.aspx/.Public/MD%20Pics?move=E7C985F306A17207!127&sid=E .......
7: Tube DIY Asylum, RE: 2w SE amp speaker choice help (0.00)
Posted by PeterP on 2010-04-22, 12:28:00 (74.105.99.250)
Exactly right. The FE107E I got from Madisound and the rest from PartsExpress. Cabinets http://www.parts-express.com/pe/showdetl.cfm?Partnumber=302-703http://www.parts-express.com/pe/showdetl.cfm?Part .......
8: Tube DIY Asylum, You've got mail. (nt) (0.00)
Posted by PeterP on 2009-06-30, 15:55:57 (74.105.113.141)
nt .......
9: Tube DIY Asylum, I’m just a bit more conservative. (0.00)
Posted by PeterP on 2009-06-01, 15:18:49 (64.241.37.140)
Check out Appendix E of: http://www.highvoltage.li/high_voltage_resources/NAVSOP-4855-1A.pdf The entire document is quite good and will help guide you to a very reliable design. Pete. .......
10: High Efficiency Speaker Asylum, RE: speakers for valve amp (0.00)
Posted by PeterP on 2009-05-12, 05:12:29 (74.105.113.141)
What size room? If you can do a little DIY, then take a look at my FE107E post below and: http://s24.photobucket.com/albums/c34/remlapretep/FE107E%20Micro%20Monitor/ I think they work well for a small .......
11: High Efficiency Speaker Asylum, RE: FE107E (0.00)
Posted by PeterP on 2009-05-05, 04:41:54 (74.105.113.141)
Wow!....and I thought I had a love affair with the small Fostex. Those look fantastic. Any thoughts about moving up the Fostex line? I'm thinking that next time I might try the FX120. Great job. Pete. .......
12: High Efficiency Speaker Asylum, FE107E (0.00)
Posted by PeterP on 2009-05-01, 07:53:26 (74.105.113.141)
Continuing my love affair with the FE107E, I recently built these monitors. Used 0.25 cu ft box from PE and really like the results. Need to do some more tweeking with Baffle Step Correction, maybe so .......
13: Tube DIY Asylum, RE: Anyone used Corian for a base plate? (0.00)
Posted by PeterP on 2009-04-29, 11:49:44 (74.105.113.141)
I would think that Corian would work IF you can get any. I've used 3/8" thick polycarbonate cutting boards. Very ease to work with. Just use standard wood drills. Larger holes are very easy with Forst .......
14: Tube DIY Asylum, RE: 6T9 Amp Pics added output wave forms. (0.00)
Posted by PeterP on 2009-03-16, 07:43:14 (74.105.113.141)
I've added wave forms now. The camera just won't take decent pics of the scope, however you'll get the idea. All pics are with both channels driven into 8 ohms (resistive) for 100Hz, 1KHz, and 10Khz ( .......
15: Tube DIY Asylum, 6T9 Amp Pics (0.00)
Posted by PeterP on 2009-03-15, 18:17:35 (74.105.113.141)
With spring break here now, I finally got a chance to take some almost decent pics of my new 6T9 Amp. I'll try to get some wave forms up in a day of two. Pete. Take a look at: http://www.flickr.com/ph .......
16: Tube DIY Asylum, RE: next time....maybe this summer (0.00)
Posted by PeterP on 2009-03-05, 15:08:03 (64.241.37.140)
I've seen that one and admit it looks interesting. However I'm going to stick with point-to-point wiring and try to expand on the e-linear approach I took with the 6T9 amp. .......
17: Tube DIY Asylum, RE: 46 Headphone Amp schematics (0.00)
Posted by PeterP on 2009-03-05, 15:04:05 (64.241.37.140)
I never did finish that amp. Took too many short cuts in the breadboard and was too lazy to make a proper heater supply. Shoot me an email and I'll share my thoughts on that amp and send you info on t .......
18: Tube DIY Asylum, 6T9 Amp schematics (0.00)
Posted by PeterP on 2009-03-05, 07:53:57 (74.105.113.141)
OK, I finally got the schematics together. These are “As Built” when I get my hands on it again I think I’ll add 0.1uF bypass caps to the power supply and maybe tweak the feedback a little. The overa .......
19: Tube DIY Asylum, RE: 6T9 Amp (0.00)
Posted by PeterP on 2009-03-05, 07:01:43 (74.105.113.141)
I'll get a schematic up shortly. The EAM86 has a small dynamic range. With only 8V needed to max it out a diode drop gives you a big dead-band before any movement is seen. It is really used as a clipp .......
20: Tube DIY Asylum, RE: next time....maybe this summer (0.00)
Posted by PeterP on 2009-03-03, 18:14:12 (74.105.113.141)
He's living on campus and only comes home for a good meal (or some help with his calc). I'm thinking that a nice EL84 PP might be a good summer project for him. I've had the parts to build my own vers .......
21: Tube DIY Asylum, 6T9 Amp (0.00)
Posted by PeterP on 2009-03-03, 16:49:40 (74.105.113.141)
My son has been using one of my headphone amps at his dorm. Even driving Pioneer 8” with a whole 1/4W. So the request was made for “more power” and some eye-candy. Thought I’d try a little 6T9 amp wit .......
22: Tube DIY Asylum, RE: Need grounding help specific to my pre-amp (0.00)
Posted by PeterP on 2008-12-03, 13:51:01 (135.245.10.4)
"DC on the 6SN7 filaments...." As always it could be just about anything. Solder joint, wiring, component placement, bad tubes, the list goes on and on. However, I do have a question. Is the heater vo .......
23: Tube DIY Asylum, RE: 2C50 info.. (0.00)
Posted by PeterP on 2008-09-20, 12:38:20 (71.172.251.16)
There sure isn't a lot of data out there, however it looks like 300V is the max. Try: http://www.ds5vxk.com/down/tube/10.pdf http://wps.com/archives/tube-datasheets/Datasheets/Raytheon-DL-Q-7101-11-56 .......
24: Tube DIY Asylum, 6DG6 (nt) (0.00)
Posted by PeterP on 2008-09-09, 15:24:04 (71.172.251.16)
nt .......
25: Tube DIY Asylum, And for a few ¢ more…… (0.00)
Posted by PeterP on 2008-09-09, 11:01:32 (71.172.251.16)
...the octal equiv 6W6GT. Have fun. .......
26: Tube DIY Asylum, When you're happy with the circuit........ (0.00)
Posted by PeterP on 2008-09-09, 08:57:53 (71.172.251.16)
....you may want to try the "upgrade" 6CS5 (if you can find any) Enjoy ;^) Pete. .......
27: Tube DIY Asylum, RE: Weird power supply help (0.00)
Posted by PeterP on 2008-07-14, 09:57:33 (135.245.152.35)
At a minimum and fairly simple to implement, I'd put a diode in series with your amp and, as Mike said, put some big capacitors right at the motor and amp. BTW is this near Santa Rosa? It's been a lon .......
28: Tube DIY Asylum, RE: Weird power supply help (0.00)
Posted by PeterP on 2008-07-13, 08:43:21 (71.127.254.105)
How much current are you trying to provide? With #14AWG and a 30'(60'round trip)run you will drop about a volt with only 6Amps. If your motor doesn't start out slow, I suspect that it will want lots o .......
29: Tube DIY Asylum, RE: Magic Eye Circuit Quest (0.00)
Posted by PeterP on 2008-04-15, 16:37:37 (71.172.48.39)
For a quick look at what's out there take a look at: http://www.akh.se/tubes/eyes.htm EAM86 tube data at: http://www.akh.se/tubes/htm/eam86.htm .......
30: Tube DIY Asylum, RE: I (respectfully) disagree with your argument (0.00)
Posted by PeterP on 2008-02-15, 06:38:32 (71.172.48.39)
I absolutely agree with you on this. When you are buying a $40,000 monitor I’ve got to believe that there is a substantial difference in the design. And that is my point exactly. The entire system is .......
31: Tube DIY Asylum, maybe I’m just as guilty (0.00)
Posted by PeterP on 2008-02-13, 12:47:25 (71.172.48.39)
Well when it comes to blanket statements maybe I’m just as guilty, and this IS the wrong forum, but what really ticked me off about the article is that the total system was never a real consideration. .......
32: Tube DIY Asylum, Cables, Cables, Cables (0.00)
Posted by PeterP on 2008-02-13, 07:34:33 (71.172.48.39)
http://www.edn.com/index.asp?layout=article&articleid=CA6418215 Articles like this give electrical engineers and PhD’s a bad name. Do these people ever listen (I mean really listen) to a quality music .......
33: Tube DIY Asylum, RE: DIY: how much PS filtering to use? (0.00)
Posted by PeterP on 2008-01-18, 07:20:11 (72.76.21.84)
Just two quick comments. 1. IIRC 40uF (plus you have 40uF isolated by only 100ohms) is too much for a 5Y3. Check the spec but I think 10-20uF is the limit. 2. The idea of replacing the 100 ohms with a .......
34: Tube DIY Asylum, RE: Finishing my Amity / Karna monoblocks (0.00)
Posted by PeterP on 2007-11-24, 17:40:41 (64.12.116.141)
If they sound as good as they look..."In one word amazing." is an understatement! I'm sure you'll enjoy them for a long time to come. Congrats, Pete. .......
35: Tube DIY Asylum, RE: Draw me a sketch of the diode trick? (0.00)
Posted by PeterP on 2007-11-23, 14:23:09 (72.76.21.84)
I used the protection diodes and CCS in my 6EM7 PP amp. Take a look at: http://www.geocities.com/remlapretep/images/6em7pp.PDF Pete. .......
36: Tube DIY Asylum, RE: one little thing...:) (0.00)
Posted by PeterP on 2007-11-23, 08:25:15 (64.241.37.140)
That's why I like the 1N4148 (1N914). IIRC Give it a try, I think you'll like it. Pete. .......
37: SET Asylum, RE: Nah! - Home Depot Cheapies. (nt) (0.00)
Posted by PeterP on 2007-11-08, 19:14:28 (72.76.21.84)
Are we talking the orange & black extension cords (IIRC Ridgid brand)? I know the 14AWG 25' is quite good for short runs ( 10'). Not my preferred cables but very good for cheap, short runs. ::: TOPIC .......
38: Tube DIY Asylum, RE: This is such cr** (0.00)
Posted by PeterP on 2007-10-30, 05:22:28 (72.76.21.84)
Gold embrittlement IS real. Is it generally a problem? NO. www.semlab.com/GoldEmbrittlementofSolderJoints.doc I've been working in electronics since '71 and in all that time I've only seen one example .......
39: Tube DIY Asylum, RE: Need a little help... (0.00)
Posted by PeterP on 2007-10-25, 16:00:51 (64.241.37.140)
Please tell me you are using two different transformers for the heaters. One for the 76 and another (or at least a different winding) for the 6SN7 heaters. If not you are exceeding the heater-to-catho .......
40: Tube DIY Asylum, RE: what would you guys call this? (0.00)
Posted by PeterP on 2007-10-23, 19:21:04 (72.76.21.84)
It's a completely different circuit. There is no ac signal at the triode cathode as there is in the first one. Not sure what to call it but, if the current in the CCS is the same as the DC current in .......
41: Tube DIY Asylum, RE: what would you guys call this? (0.00)
Posted by PeterP on 2007-10-23, 18:45:02 (72.76.21.84)
It's just a long tail pair phase splitter. If you are looking at just one output it's just a differential output stage. Look at the Ultra Compact: http://www.diyparadise.com/ecc99el84c.gif replace the .......
42: Tube DIY Asylum, RE: Thinking about an EL84 PP project (0.00)
Posted by PeterP on 2007-10-15, 05:27:40 (72.76.21.84)
Any thoughts about this one? I haven't heard it, but it looks interesting. http://www.tube-amps.net/EA_Hashimoto_EL84_PP_01.htm .......
43: Computer Audio Asylum, Oh my.....and a big thank you. (0.00)
Posted by PeterP on 2007-09-19, 19:22:16 (205.188.116.141)
I never stop by here and did so today simply by accident. All I can say is that I'm very glad I did. I've been listening to USF Jazz 1.4mb and I'm really enjoying it. Thanks for posting. Pete. PS I'll .......
44: Tube DIY Asylum, RE: DIY headphone amp suggestions for 300 ohm (0.00)
Posted by PeterP on 2007-09-01, 11:50:07 (72.76.21.84)
FWIW I like a 6SN7 SRPP followed by a 6SN7 White Follower into an output transformer but you've got lots of options. Think about how much gain you really need. I'd think more than 1.5 but less than 10 .......
45: Tube DIY Asylum, OT..for those over 50 et. al. (0.00)
Posted by PeterP on 2007-09-01, 07:45:57 (72.76.21.84)
Well after putting things off ‘till now (54) most everything has checked out fine. Except one. My PSA came back high (5.8) and after several tests it was time for a prostate biopsy. Had it done and, a .......
46: Bottlehead Forum, "Green Wire" (0.00)
Posted by PeterP on 2007-08-16, 20:49:39 (72.76.21.84)
When it comes to "safety ground" you really need to make sure that any conductive surface that you can touch is connected to "safety / earth" ground. Then work your hum issues, circuit ground, etc. On .......
47: Bottlehead Forum, That's why I...... (0.00)
Posted by PeterP on 2007-08-15, 20:47:04 (72.76.21.84)
....always use an IEC input connector with dual fuses. I just don't want to depend upon the input power being wired right (correctly) at the outlet. Plus it really is a necessity if you ever use balan .......
48: Tube DIY Asylum, Good luck and remember......... (0.00)
Posted by PeterP on 2007-08-14, 20:21:47 (205.188.116.141)
......even it you can't actively pursue the material aspect of this hobby, you are more than welcome to share your knowledge and stay up-to-date with the changing DIY audio scene here. Take care. Pete .......
49: Tube DIY Asylum, RE: Interesting SE amp concept using offset winding (0.00)
Posted by PeterP on 2007-07-18, 20:54:03 (205.188.116.16)
JeffreyJ makes a good point about the filaments. If you get the thump immediately at turn-on, it could well be the current from the DC supply to the filament. Make sure that the DC to the filaments ra .......
50: Tube DIY Asylum, RE: Lorlin - Are they ............. (0.00)
Posted by PeterP on 2007-07-10, 19:14:47 (64.12.117.11)
Sounds like a fun project. With any luck I'll make the next meet. Pete. .......
51: Tube DIY Asylum, RE: Lorlin - Are they ............. (0.00)
Posted by PeterP on 2007-07-09, 20:34:14 (152.163.100.16)
all plastic/nylon? Including the shaft? I've been using E-Switch KC series and like everything about them but I'd like to find a cost effective metal shaft rotory switch for "hard use" applications. h .......
52: Tube DIY Asylum, Could you...... (0.00)
Posted by PeterP on 2007-06-29, 17:28:49 (72.76.21.84)
......post a full schematic? The reason the diode worked in the example below has nothing to do with noise or hum. It has everything to do with the timing (sequencing) of the B+ for the output and gai .......
53: Tube DIY Asylum, RE: I second that idea (0.00)
Posted by PeterP on 2007-06-27, 05:09:03 (64.12.117.11)
"....I am going to put another bleed resistor across the 50uf cap so it can still discharge...." Absolutely! Always make sure that there is a discharge path for all caps that could hold a dangerous ch .......
54: Tube DIY Asylum, RE: CCS loaded 6SN7 driver, switch off pulse. (0.00)
Posted by PeterP on 2007-06-26, 12:43:41 (64.12.117.11)
Just a thought. Try adding a diode (1N4007 etc. Please forgive me, I know, a SS part) in series with the 1.8K resistor and before the 50uF cap. That should allow the gain/driver circuit to be well beh .......
55: Tube DIY Asylum, RE: Magic eye tubes - stereo peak-reading type. (0.00)
Posted by PeterP on 2007-06-01, 04:54:24 (72.88.208.200)
If you haven't been to these sites you should check them out. http://koti.mbnet.fi/siliconf/JukkaTolonen/ga/peakmtr/peakmtr.html http://www.akh.se/tubes/eyes.htm http://audiohobbyist.com/projects/magi .......
56: Tube DIY Asylum, RE: 46 Based Amp (0.00)
Posted by PeterP on 2007-05-27, 18:33:28 (72.88.208.200)
Are you doing a class B amp? No this will be a class A, single ended amp intended to be mostly a headphone amp. For about the past two years I have been thinking about a PP amp that would be switchabl .......
57: Tube DIY Asylum, RE: IXYS (0.00)
Posted by PeterP on 2007-05-27, 07:15:46 (72.88.208.200)
I was just getting ready to post and I see I was just a bit too slow ;^) I guess I was just too long winded but, here it is anyway. I think you are talking about this one from IXYS available from Digi .......
58: Tube DIY Asylum, RE: my new oscillator....Silly question. (0.00)
Posted by PeterP on 2007-05-22, 18:55:10 (72.88.208.200)
Do you really have negative feedback? If it's stable without feedback you could have the phase reversed somewhere in your system. Check and then double check the phasing of all the parts in the amp. S .......
59: Tube DIY Asylum, Re: CCS under the output tube? (0.00)
Posted by PeterP on 2007-05-11, 06:17:18 (72.88.208.200)
That's not the right symbol. My guess is that the AM next to it is for ammeter. If you take a look at the prototype there is a nice big meter on the front panel. Pete. .......
60: Tube DIY Asylum, Re: Drastic measures in Desparate Times.........(long) (0.00)
Posted by PeterP on 2007-04-24, 05:58:01 (72.88.208.200)
Just a quick question. My understand is that with the inputs shorted (ie. no preamp or source) you have hiss that is volume dependent. So, if you unplug the amp under these conditions, is the hiss sti .......
61: Tube DIY Asylum, It's more a question of....... (0.00)
Posted by PeterP on 2007-04-17, 05:33:29 (72.88.208.200)
....how hot do you want your wires to get? #20AWG copper wire is roughly a 58Amp fuse. If you use the standard of 700 circular mills/amp then it's rated for about 1.5Amps. Why not Google "wire ampacit .......
62: Tube DIY Asylum, Re: My SE Amp Update - Tube Swapping (0.00)
Posted by PeterP on 2007-04-13, 12:14:54 (72.88.208.200)
You may also want to try the JJ KT88. I used it a few years ago in an SE-UL and seem to recall it sounding pretty good to me. Have fun. Pete. .......
63: Tube DIY Asylum, Sovtek 6SN7s (0.00)
Posted by PeterP on 2007-04-08, 18:49:16 (71.172.251.133)
"...Sovtek 6SN7s, which are not generally considered to be among the best sounding tubes of that type." I must agree with you there. I have tried them as a White Follower and found them to be fairly g .......
64: Tube DIY Asylum, Re: is this the correct way of adding volume control? (0.00)
Posted by PeterP on 2007-03-29, 10:45:20 (71.172.251.133)
Just my 2. That will work just fine, however I'd suggest you consider lowering the value of the pot to 50K or less (you may like 25K even better, if your source will support it). I've also had very g .......
65: Tube DIY Asylum, Re: Question about basic power equation for CT transformer. (0.00)
Posted by PeterP on 2007-02-09, 12:43:55 (72.88.208.196)
Not quite. You need to spend some time reading over... http://www.hammondmfg.com/pdf/5c007.pdf That should get you where you need to go. If you don't understand, keep asking questions. Pete. ::: TOPIC .......
66: Tube DIY Asylum, Re: Why not tell me about your headphone amp? (nt) (0.00)
Posted by PeterP on 2007-02-08, 09:37:34 (72.88.208.196)
Start with: http://db.audioasylum.com/cgi/m.mpl?forum=tubediy&n=102420&highlight=PeterP&r=&session= While building it (in its final wood chassis) I found that grounding (circuit and safety ground) was .......
67: Tube DIY Asylum, Re: Nada, attenuation alone would not kill the noise. (0.00)
Posted by PeterP on 2007-02-07, 14:07:35 (72.88.208.196)
I agree 100%. That's why I spent all the time and effort when I did my headphone amp. My understanding is that he would like to get what he has to work the best it can without major changes. To that e .......
68: Tube DIY Asylum, Re: Headphone out from OPT (0.00)
Posted by PeterP on 2007-02-07, 06:03:53 (72.88.208.196)
To use a power mains toroid, you need to make sure that there is NO dc in the primary. So...you must either use parafeed or some other means of keeping the dc current out of the transformer. You could .......
69: Tube DIY Asylum, Re: Headphone out from OPT (0.00)
Posted by PeterP on 2007-02-06, 15:01:54 (72.88.208.196)
Assuming that you are not going to change the overall gain of your amp and you are using the 8 ohm output, a bit more information is needed. What's the impedance of the headphones that you're using? Y .......
70: Tube DIY Asylum, That's fine. (nt) (0.00)
Posted by PeterP on 2007-01-29, 18:20:25 (72.88.208.196)
. .......
71: Tube DIY Asylum, Not so fast............. (0.00)
Posted by PeterP on 2007-01-29, 14:44:57 (72.88.208.196)
Keep in mind the "heater to cathode" voltage spec of the tube you're using. If your input is an SRPP or if you are directly coupled to a driver stage, you'll need to bias up the heater voltage. I woul .......
72: Tube DIY Asylum, Re: Pinging PeterP .here is my 807PP circuit (0.00)
Posted by PeterP on 2007-01-29, 05:20:37 (205.188.116.66)
Your schematic doesn't really show if each component is brought back to the single point ground or if they are grouped. Both ways can be made to work. (If you go to the bottom of my blog page you'll s .......
73: Tube DIY Asylum, Re: Single Ended KT88 (0.00)
Posted by PeterP on 2007-01-25, 16:35:21 (72.88.208.196)
IMO the Aikido makes a good preamp for driving long cables and does a very good job as a headphone amp. In this case it simply adds another stage that isn't necessary. Will it work? Yes, and you may p .......
74: Tube DIY Asylum, Re: Pinging PeterP . the hum partly solved (0.00)
Posted by PeterP on 2007-01-25, 16:18:22 (72.88.208.196)
Good to hear that you're making progress. If at all possible, post a schematic to show how it is wired up. (I'm having a hard time following what you've done.) Another thought. I don't recall you said .......
75: Tube DIY Asylum, I'd also........ (0.00)
Posted by PeterP on 2007-01-23, 19:43:09 (72.88.208.196)
....lower the value of your grid stopper. 3.3K for a 6J5 seem way too high to me. Try something closer to 150 ohms or less. When you are "all done" making changes, the grid stopper (if needed) should .......
76: Tube DIY Asylum, Re: Hum problem with my stereo 807pp DIY power amp (0.00)
Posted by PeterP on 2007-01-23, 18:08:22 (72.88.208.196)
FWIW I've got 3 suggestions. 1. From what you say it seems that the circuit ground and earth ground are not connected in any way. If you do a search I'm sure you'll find several recommendations from y .......
77: Tube DIY Asylum, Re: Hum problem with my stereo 807pp DIY power amp (0.00)
Posted by PeterP on 2007-01-23, 09:06:33 (72.88.208.196)
Just some random thoughts to consider. 1. Is your single point ground (the place where circuit power and earth ground are tied together) at the input RCA connectors or back at the last power supply ca .......
78: Tube DIY Asylum, Check out........ (0.00)
Posted by PeterP on 2006-12-30, 13:50:07 (72.88.208.196)
http://www.dscc.dla.mil/Programs/MilSpec/DocSearch.asp?SrchTEXT=5960&SrchField=FSC That like should provide you with more reading than you probably care to do over the next life time (or two). ;^) Enj .......
79: Tube DIY Asylum, Looks like MIL-STD-1311 (0.00)
Posted by PeterP on 2006-12-30, 13:39:42 (72.88.208.196)
As I said, there's a mil spec for just about anything you can think of. I didn't spend too much time reading it, but it looks like 1311 covers what you're looking for. From the Mil-STD: MIL-STD-1311C .......
80: Tube DIY Asylum, Mil-Std-901 (0.00)
Posted by PeterP on 2006-12-30, 12:49:21 (72.88.208.196)
IIRC Mil-Std-901 covers the hammer drop test (shock). There are standards for different grades and class of equipment. The one I'm most familiar with is 100g's for 11 mSeconds half sine wave shock pul .......
81: Tube DIY Asylum, Re: Puzzled by the Hammonds VA ratings (0.00)
Posted by PeterP on 2006-12-22, 18:40:56 (72.88.208.196)
"Perfect" core materials and super conductors are coming. Just don't hold you breath. ;^) .......
82: Tube DIY Asylum, Re: Puzzled by the Hammonds VA ratings (0.00)
Posted by PeterP on 2006-12-22, 18:11:27 (72.88.208.196)
"I have always considered volt-amp rating to be for the primary current drawn" Quite true. That's why the "Very Simplified" approach is just that, an approximation of what the primary will see when di .......
83: Tube DIY Asylum, Re: Very simplified. (0.00)
Posted by PeterP on 2006-12-22, 15:31:15 (64.241.37.140)
When you use a choke input the power factor improves IIRC ~0.85 is a fair estimate. In that case: DC with choke input: VA = 625*sqrt(2)*2/(pi) * .3 / 0.85 = 200VA so with a cap input: current = 0.65 * .......
84: Tube DIY Asylum, Very simplified. (0.00)
Posted by PeterP on 2006-12-22, 12:24:31 (72.88.208.196)
You need to keep in mind that VA is not Watts. My usual estimate is: For cap input DC: VA = 375*sqrt(2)*0.175/0.65 = 375*1.414*0.175/0.65 = 143VA Where does the 0.65 come from? It's the "typical" powe .......
85: K&K Audio / Lundahl Transformers, Thanks for the info. (nt) (0.00)
Posted by PeterP on 2006-12-21, 11:14:17 (72.88.208.196)
.. .......
86: K&K Audio / Lundahl Transformers, Re: Not quite an Aikido, but........ (0.00)
Posted by PeterP on 2006-12-21, 08:01:08 (72.88.208.196)
Thanks Kevin. I guess I over looked the LL1689 since the data sheet says that it is "To be completed". The I^2R losses of the LL1660 are what has kept me from trying it. Looks like the LL1689 would gi .......
87: K&K Audio / Lundahl Transformers, Not quite an Aikido, but........ (0.00)
Posted by PeterP on 2006-12-21, 05:05:01 (72.88.208.196)
Here's a schematic of my (Aikido / Morgan Jones inspired) Headphone Amp. http://www.geocities.com/remlapretep/hpa1.pdf You can read more about it at my blog. http://journals.aol.com/php289/TubeTown/ I .......
88: Tube DIY Asylum, Re: psu2 questions (0.00)
Posted by PeterP on 2006-12-18, 15:39:37 (64.241.37.140)
When I've been that far off on the actual voltage, it's been do to the "step" load being active when I thought it was off. You may want to double check that you don't have a step load that changes at .......
89: Tube DIY Asylum, Re: Where would you look at? (0.00)
Posted by PeterP on 2006-12-08, 17:21:04 (64.241.37.140)
Are the circuit ground and safety ground tied together at some point in the system? If not you may try grounding the circuit ground to the safety ground. Check the archives, there are lots of ways to .......
90: Tube DIY Asylum, Beautiful work! (nt) (0.00)
Posted by PeterP on 2006-11-17, 20:04:13 (152.163.101.6)
nt .......
91: Tube DIY Asylum, Re: volume pots (0.00)
Posted by PeterP on 2006-11-17, 19:49:37 (152.163.101.6)
Just some thoughts on your Aikido. As a compromise you might consider using output transformers. A fairly small stepdown transformer would reduce the output impedance (which is already quite low) and .......
92: Tube DIY Asylum, Re: Calculating Battery Size (0.00)
Posted by PeterP on 2006-11-16, 16:17:15 (64.241.37.140)
You need to get the discharge curves for your battery. A lot of small SLA batteries are based upon the 20-hour discharge rate. At your 2-hour rate it will be quite a bit less. Once you have the curves .......
93: Tube DIY Asylum, Re: CCS and drop voltage vs. good sound. (0.00)
Posted by PeterP on 2006-11-10, 19:46:40 (152.163.101.6)
That site belonge to Pete Millett (not me) and yes, he does have a lot of very good info there. As for the "mu" output I believe you are correct in that the power supply is now back in the signal path .......
94: Tube DIY Asylum, Re: Ping: PeterP and zobsky..... (0.00)
Posted by PeterP on 2006-11-10, 13:02:16 (72.88.208.196)
Thanks for the post. No cathode bypass cap? Did you try one? Can't wait to hear you comments about AC heaters ;^) Have fun. Pete. .......
95: Tube DIY Asylum, Re: CCS and drop voltage vs. good sound. (0.00)
Posted by PeterP on 2006-11-10, 12:46:36 (64.12.116.131)
Yes 10V is the minimum you can get away with under static conditions. How much signal voltage are you trying to get out? I have also found that I like at least 20V of headroom (this seems to be a case .......
96: Tube DIY Asylum, Re: DIY Headmp for Sennheiser-650? (0.00)
Posted by PeterP on 2006-11-09, 12:15:27 (205.188.116.66)
Try spending some time over at: www.headfi.org I'm sure if you post a question there, you will get even more suggestions. Just to muddy-up the waters ;^) I was just at the NYC meeting (11/4) and there .......
97: Tube DIY Asylum, Re: Power supply choke on the return leg (0.00)
Posted by PeterP on 2006-11-08, 08:18:34 (64.12.116.131)
Good point that I did fail to mention. When using two seperate chokes, you get DM and CM noise reduction. At the expense of physical size. Also, since I build a lot on isolated (insulated) chassis, I .......
98: Tube DIY Asylum, Re: Power supply choke on the return leg (0.00)
Posted by PeterP on 2006-11-08, 05:37:28 (72.88.208.196)
Up till now I've used separate identical chokes. The latest breadboard, EL84 PP, is using a modified ELLA choke (see AA sponsor DIY Hifi Supply), I simply rewired the two coils so that I could put one .......
99: Tube DIY Asylum, That is fantastic! (0.00)
Posted by PeterP on 2006-11-07, 13:00:49 (64.12.116.131)
You kept as much wood as possible. Every part and wire in it's own machined pocket. Very, very nice! I LIKE IT! Don't take this the wrong way but, I like the inside even more than the outside. Great w .......
100: Tube DIY Asylum, Re: Power supply choke on the return leg (0.00)
Posted by PeterP on 2006-11-07, 12:53:21 (64.12.116.131)
The practice of putting the choke in the return leg has been used for years in switching power supplies. If you are using SS diodes with metal cases, you can greatly reduce the common mode noise by pu .......
101: Tube DIY Asylum, Re: where in the datasheet... (0.00)
Posted by PeterP on 2006-11-06, 19:48:01 (72.88.208.196)
I just through out the 6EM7 as a maybe. It has two triodes in it. Unit 1 is a low power triode like the 6SL7. Unit 2 is a high power triode good for 10W. There is a lot more that needs to be considere .......
102: Tube DIY Asylum, I must have been sleeping. (0.00)
Posted by PeterP on 2006-11-06, 19:08:54 (152.163.101.6)
"I then inserted the TL431 and 6SL7GT to the shunt regulator circuit." A 6SL7 won't handle the no-load requirements of 150V / 75mA. That's over 11W. At most it's good for just a few mA. Good idea, wro .......
103: Tube DIY Asylum, Re: something is wrong with the shunt regulator (0.00)
Posted by PeterP on 2006-11-06, 17:07:47 (64.241.37.140)
First, a couple of assumptions: Your power transformer is 260 – 0 – 260 or 520 Vct When your output voltage is 147V with the 2K load, you get 2.5V at the junction of R1-R2. You then remove the 2K load .......
104: Tube DIY Asylum, Details, details....... (0.00)
Posted by PeterP on 2006-11-06, 16:22:21 (64.241.37.140)
That is one fine looking preamp! Please provide more details. Which OTs, schematic, more, give me more. Seriously, very nice work. Pete. .......
105: Tube DIY Asylum, Re: SRPP heater/cathode biasing question... (0.00)
Posted by PeterP on 2006-11-03, 20:33:07 (205.188.116.66)
You need to re-read the last page of: http://www.wavelengthaudio.com/bugle.pdf He explains it pretty well. If you have any further questions ask. Don't just go away not understanding. If I had to gues .......
106: Bottlehead Forum, Silly question. (0.00)
Posted by PeterP on 2006-11-03, 06:01:29 (205.188.116.66)
"I wonder why the hum is present when the FP is on but it isn't when the amp is on alone; it would seem since the hum is influenced by the 'fridge that it would affect both the amp and the FP?" Just a .......
107: Bottlehead Forum, Glad to hear he's back and safe. (nt) (0.00)
Posted by PeterP on 2006-10-31, 04:32:16 (152.163.101.6)
. .......
108: Tube DIY Asylum, Damn, mid-day and I'm still not awake. (0.00)
Posted by PeterP on 2006-10-27, 09:20:21 (72.88.208.196)
You're absolutely right. Time to get some caffeine. My apologies for being so hasty. Pete. BTW Try the SRPP without the cathode bypass cap C30, less gain, but you may find that you like it better (or .......
109: Tube DIY Asylum, The 6DJ8 section is not drawn correctly. (0.00)
Posted by PeterP on 2006-10-27, 08:32:50 (64.12.116.131)
Assuming that it's working, it needs to be redrawn to correctly show what's actually in the circuit (It won't work as drawn). Also (just a "by-the-way") there is only one of two protection diodes for .......
110: Tube DIY Asylum, Re: gary pimm's latest self-biasing CCS circuit (0.00)
Posted by PeterP on 2006-10-04, 19:17:35 (72.88.208.162)
As for your questions 1&2, you are correct. The voltage across C2 is the ref. voltage (0.35mA * 27K = ~9.5V) and, when used as a current source (plate load) the "-" lead (after R1) connects to the pla .......
111: Bottlehead Forum, Re: buzz, not a hum (0.00)
Posted by PeterP on 2006-09-27, 21:04:36 (64.12.116.131)
Just a thought. Is it possible that the buzz has always been there and you are just noticing it now? When I built my original FP, I had to isolate the mains power transformer to eliminate a buzz. If y .......
112: Tube DIY Asylum, Just a few more points. (0.00)
Posted by PeterP on 2006-09-26, 05:08:25 (64.12.116.131)
To expand upon what’s already been said, there are 3 main points to consider for the circuit as shown: 1. The cathode voltage should not exceed 0.7*36Vdc or ~ 25V 2. The cathode current should not exc .......
113: Tube DIY Asylum, Re: DIY passive pre w/ST70 (0.00)
Posted by PeterP on 2006-09-18, 15:56:22 (64.241.37.140)
Since you already are using the Radio Shack 100K pot you might want to consider using two of them. If you have the room, put another 100K pot in and wire each as a single 50K pot (just parallel the tw .......
114: Tube DIY Asylum, Re: help with transformer primary (0.00)
Posted by PeterP on 2006-09-12, 05:06:53 (72.88.208.162)
That's it. Notice the dots on the coils, that's the key. So if you connect the yellow and green wires you're set for 230Vac. Take care. Pete. .......
115: Tube DIY Asylum, Re: Big Blue finally gets real data. (long) (0.00)
Posted by PeterP on 2006-09-10, 07:03:35 (72.88.208.162)
Thanks, that's pretty much the look I was shooting for ;^) As for the box construction you can check out the links below. I'm sure I spent more $ on the paint than the box. http://db.audioasylum.com/c .......
116: Tube DIY Asylum, Big Blue finally gets real data. (long) (0.00)
Posted by PeterP on 2006-09-08, 20:48:13 (64.12.116.131)
Thank you DrD for finally getting me off my butt and taking some real data on my 6EM7 PP Amp. http://www.geocities.com/remlapretep/php_audio.htm All data taken with 10 ohm loads on each channel. For H .......
117: Tube DIY Asylum, Re: Look here (0.00)
Posted by PeterP on 2006-09-07, 16:52:06 (64.241.37.140)
Tre' is right. I also get the same numbers. I suspect that, if the components are entered correctly, the current load may be stepped. Double check the load and make sure that it is not in step mode. O .......
118: SET Asylum, Re: Some troubles with PSUD. A little help please ! (0.00)
Posted by PeterP on 2006-09-07, 16:34:46 (152.163.101.6)
Check and then double check what you are putting into the simulation. I just ran the numbers and get just under 400V without any tweeks. I suspect that there may be something not right with what you h .......
119: Bottlehead Forum, Not Eli Duttman, but this may help. (0.00)
Posted by PeterP on 2006-09-07, 15:44:28 (64.241.37.140)
You don't need a center tap to make this work. Think of the 6X4 as just two diodes with their cathodes connected. Now construct a rectifier bridge with two more diodes (SS) and connect their anodes. A .......
120: Tube DIY Asylum, 53 born in '53 (0.00)
Posted by PeterP on 2006-08-25, 08:19:32 (64.12.116.131)
There seems to more interest in tube amps in the general public. I just got an email from my brother-inlaw about a recent ad in Men's Journal Mag for a tube amp (I haven't seen it yet.). Maybe there's .......
121: Tube DIY Asylum, Re: where do you get your r-core transformers? thanks (nt) (0.00)
Posted by PeterP on 2006-08-05, 07:51:56 (172.147.187.138)
I've never used them, but vt4c.com seems to have a lot of interesting parts including R-Core transformers. http://www.vt4c.com/shop/program/main.php?cat_id=55&group_id=7&hit_cat= .......
122: Bottlehead Forum, Thanks for the pics. (0.00)
Posted by PeterP on 2006-07-29, 05:50:07 (152.163.101.6)
Very nice. Wish I'd been there. Could someone please comment or provide more info about those 4" Fostex speakers? I have mine in a small 6L ported box. I'd like to know what people think of them in a .......
123: Tube DIY Asylum, Re: Goodbye Yellow Brick Road (0.00)
Posted by PeterP on 2006-07-25, 12:52:09 (172.131.225.102)
Best of luck to you. If you feel it's time to move on, then it is. You're always free to lurk and comment on off-topics. Again best wishes. Pete. BTW I too would appreciate an email just to know where .......
124: Bottlehead Forum, Wish I could make it. (0.00)
Posted by PeterP on 2006-07-21, 08:59:55 (172.131.225.102)
Sterling is just too far for me. Take lots of pics. Have fun. Pete. .......
125: Tube DIY Asylum, How about..... (0.00)
Posted by PeterP on 2006-07-21, 06:10:28 (172.131.225.102)
Fig. 4 at: http://dkc3.digikey.com/PDF/T062/1362-1364.pdf or something from: http://www.vt4c.com/shop/program/main.php?cat_id=6&group_id=2 Note that the vt4.com stuff is metric (for 6mm shafts) I've u .......
126: Tube DIY Asylum, Re: Hammond 193 series chokes with choke input (0.00)
Posted by PeterP on 2006-07-21, 04:51:57 (172.131.225.102)
I've had them buzz. However, if you add a cap as Chris O suggests, you will eliminate the buzz. Depending on your application (and current draw) going even as high as 1 - 2uF will not change the outpu .......
127: Bottlehead Forum, Re: Speaker wire gauge (0.00)
Posted by PeterP on 2006-07-17, 11:28:44 (172.131.225.102)
Boy are you going to get all kinds of answers ranging from single strand 30AWG magnet wire to power cord wire from Home Depot to silver foil. My personal favorite (right now) for You really need to tr .......
128: Bottlehead Forum, Bring your headphones. (0.00)
Posted by PeterP on 2006-07-17, 11:16:52 (172.131.225.102)
Looks like the email worked this time. I'll bring my 6SL7/6SN7 headphone amp, a pair of Fostex FE107E (6L dual port), and some miscellaneous stuff. So....feel free to bring your headphones and give th .......
129: Bottlehead Forum, You've got mail. (0.00)
Posted by PeterP on 2006-07-16, 15:52:48 (152.163.101.6)
I sent you another email. Maybe this time things will work. Thanks. Pete. .......
130: Bottlehead Forum, Now if I could only spell..... (0.00)
Posted by PeterP on 2006-07-15, 18:19:05 (205.188.116.66)
That's Gesashi. .......
131: Bottlehead Forum, And to think some people pay extra for that. (0.00)
Posted by PeterP on 2006-07-15, 17:27:52 (205.188.116.66)
I know exactly what you're talking about. I spent '74 in Gasashi. Well, the rainy season is coming ;^) .......
132: Bottlehead Forum, Re: cathode bypass cap size (0.00)
Posted by PeterP on 2006-07-10, 11:13:28 (205.188.116.66)
My "over-kill" method. Use a 5Hz cut off Equiv. resistance = (Rp parallel R-load)/mu parallel with Rk C = 1/(2*pi*Requiv*5Hz) and then round up to the next standard value. Seems to work for me. Being .......
133: Bottlehead Forum, ....and let's not forget William Shatner. (0.00)
Posted by PeterP on 2006-07-10, 10:54:49 (205.188.116.66)
His Mr. Tambourine Man will send her screaming out of the house. Check out: http://www.amazon.com/gp/product/B0000089JE/104-6459052-8166358?v=glance&n=5174 for that can't miss combination. ::: TOPIC:: .......
134: Bottlehead Forum, Re: Different cathode resistor values for the Paramount 2A3 (0.00)
Posted by PeterP on 2006-07-09, 07:38:18 (172.162.145.106)
The ammeter would go in series with the cathode resistor(/resistor combination). That's the easy part. As for the different cathode resistor values, there are several ways to go. However, I'd suggest .......
135: Bottlehead Forum, OT Bottlenecks, I need some advice. (0.00)
Posted by PeterP on 2006-07-08, 04:39:16 (172.162.145.106)
Next Saturday I'll be picking up my son at UM (College Park). On the way back to NJ (along I-95) where should we stop for a bite to eat? We've done the Inner Harbor tourist thing. It wouldn't seem rig .......
136: Tube DIY Asylum, If you haven't looked at.......... (0.00)
Posted by PeterP on 2006-06-30, 17:06:39 (205.188.116.66)
Memmo Vanderveen's site: http://www.mennovanderveen.nl/eng/index.html you should at least give it a read. I haven't tried it yet but "Super-Triode" is on my list of things to try out. Go to Vanderveen .......
137: Tube DIY Asylum, Very nice. Thanks. (nt) (0.00)
Posted by PeterP on 2006-06-28, 20:43:05 (172.134.154.254)
nt .......
138: High Efficiency Speaker Asylum, Re: Speakers for flea power systems? (0.00)
Posted by PeterP on 2006-06-28, 19:08:43 (172.134.154.254)
You're quite right. In order to hit the 105dB/W/m levels needed to make it decent levels (not quite realistic classical levels) I guess you do need 110dB/W/m+ speakers. So the question is, to get to t .......
139: High Efficiency Speaker Asylum, Speakers for flea power systems? (0.00)
Posted by PeterP on 2006-06-28, 13:38:07 (172.134.154.254)
Just thinking outloud here. To fill even a moderate sized room with music from a sub watt amp I would think that you would need to join the 104+dB/W/m club. So what can be done? I haven't looked into .......
140: Tube DIY Asylum, I should talk. (0.00)
Posted by PeterP on 2006-06-24, 18:32:31 (172.144.245.210)
Believe it or not I just noticed that the poster 0,4,0,1,0 was his answer! Sometimes my glasses don't work and sometimes I just refuse to see. Take care. Pete. .......
141: Tube DIY Asylum, Re: One inductor. Two identical windings. Pop quiz. (0.00)
Posted by PeterP on 2006-06-24, 15:16:40 (172.144.245.210)
Good one. You are correct even "A 10k resistor in parallel with a piece of wire is still 10k." However the resulting, two terminal device, still will measure 0 ohms. Let's not confuse the poor lad ;^) .......
142: Tube DIY Asylum, It's not just you. (nt) (0.00)
Posted by PeterP on 2006-06-24, 12:28:38 (172.144.245.210)
. .......
143: Tube DIY Asylum, Re: "island" effect?? (0.00)
Posted by PeterP on 2006-06-24, 12:26:37 (172.144.245.210)
The power section of the 6EM7 is one of those tubes that simply sounds best when operated at the recommended op points. 150V plate, -20V grid, and 50mA. As you move away from that op point, you will n .......
144: Tube DIY Asylum, Paul, wake up ;^) (0.00)
Posted by PeterP on 2006-06-24, 12:08:25 (172.144.245.210)
"on a common core inductance increases cubically with turns." Paul, you're typing funny today ;^) The inductance is proportional to the number of turns squared. So twice the number of turns = 4x induc .......
145: Tube DIY Asylum, Re: One inductor. Two identical windings. Pop quiz. (0.00)
Posted by PeterP on 2006-06-24, 06:39:17 (64.241.37.140)
Finally someone taking the question for real. But it's: One winding, measured alone, the other open: L = 1H One winding, measured alone, the other shorted: L = ?.........0H...* Two windings, measured .......
146: Tube DIY Asylum, Re: LT1085 Current Regulation for DHT filaments (0.00)
Posted by PeterP on 2006-06-23, 21:51:25 (152.163.101.6)
Are you sure that it's not a 0.520 ohm resistor? That would make more sense. 1.25V/0.52=2.4A "Another question: is the formula of LT1085 (3A) the same as LT1083 (7.5A)?" Yes. .......
147: Tube DIY Asylum, Re: ?? which section (0.00)
Posted by PeterP on 2006-06-23, 16:27:06 (64.241.37.140)
Yes, section 2 (unit 2) is the power triode section. I've seen that with the 6EM7, it is much more sensitive to the "island" effect when used as a SET amp. It's not quite as pronounced in push-pull. A .......
148: Tube DIY Asylum, Re: No CT help! You can get away with...... (0.00)
Posted by PeterP on 2006-06-23, 12:25:14 (172.134.16.206)
.....using 3 tube diodes. A dual and 2 singles (or duals configured as singles). If the singles are IDH you'll may get away with only one other heater voltage. Just my 2 Pete. .......
149: Tube DIY Asylum, Re: Rectifier Amperage Ratings? (0.00)
Posted by PeterP on 2006-06-22, 13:07:54 (172.134.16.206)
For me, there are two main reasons: 1. Keep SS parts cool. Heat kills SS parts. By using "over rated" parts you will keep the junction temperatures down. 2. Fault survival. When something down stream .......
150: High Efficiency Speaker Asylum, Re: Fostex FW208N any comments? (0.00)
Posted by PeterP on 2006-06-22, 12:50:23 (172.134.16.206)
Yes, they are a bit pricey for just a simple 8" woofer. That's why I'd like to hear from someone who has heard them. In this case I'm looking for a nice balance of sound, looks, and price. And you're .......
151: High Efficiency Speaker Asylum, Fostex FW208N any comments? (0.00)
Posted by PeterP on 2006-06-21, 13:31:58 (172.134.16.206)
I'm thinking about a small 2way mini-monitor and like the looks of this woofer. In an 8 liter ported box tuned to about 57Hz I get reasonable results using WinISD. If I cross over a 90dB/W/m tweeter a .......
152: Bottlehead Forum, Re: Small Desktop speakers for S.E.X amp? (0.00)
Posted by PeterP on 2006-06-20, 07:18:25 (152.163.101.6)
How small is small? How about a 4" Fostex, FE107E, in 6"w x 12.5"h x 10.75"d? Check my Sept. post. http://db.audioasylum.com/cgi/m.mpl?forum=bottlehead&n=100772&highlight=fe107e+PeterP&r=&session= The .......
153: Tube DIY Asylum, Exactly. (0.00)
Posted by PeterP on 2006-06-17, 08:16:33 (64.12.116.131)
You'll need to bypass R2 with a cap. I find 22uF a nice convenient value and, so far, haven't seen where the type of cap really matters in that position. As long as you use a reliable cap, rated for 2 .......
154: High Efficiency Speaker Asylum, Re: nice. (0.00)
Posted by PeterP on 2006-06-15, 16:23:54 (64.241.37.140)
Can you run these from a PC sound card? Well the short answer is yes. Will it sound good...NO. I just tried my ThinkPad and at anything more than very soft conversation levels the sound card falls apa .......
155: High Efficiency Speaker Asylum, Re: fe-103 vs. fe-103e and SD speaker designs (0.00)
Posted by PeterP on 2006-06-15, 06:19:20 (172.147.49.129)
When I did my FE107E I started with Godzilla's site: http://www.zillaspeak.com/ZillaSpeakFostex103-RS1197.asp I then adjusted the SOLO-103 to ~6l and ended up with: http://db.audioasylum.com/cgi/m.mpl .......
156: Tube DIY Asylum, Re: about that power supply... (0.00)
Posted by PeterP on 2006-06-15, 05:12:31 (172.147.49.129)
I’m sure that there isn’t much common mode noise that gets through the transformer, but keeping the filter balanced helps get rid of what does get in. A CMC would probably do the job. I would have lik .......
157: Tube DIY Asylum, Re: yes nice (0.00)
Posted by PeterP on 2006-06-14, 04:37:48 (205.188.116.66)
The transformer that I used can be found at: http://dkc3.digikey.com/PDF/T062/1699-1700.pdf Amveco part number 70045 it's a 10VA transformer with 2x 115V primaries 2x 22V secondaries It's a toroidal p .......
158: Tube DIY Asylum, Re: I have no plans of referencing this heater to ground. thanks :) (NT) (0.00)
Posted by PeterP on 2006-06-13, 17:56:10 (172.147.49.129)
Mark is quite right. You can use regulated DC however it will be floating on the B+ voltage. Keep that in mind when using heatsinks etc. The data sheet for a 5U4 clearly states the the heater can be A .......
159: Bottlehead Forum, Re: Capacitors in Power supply question: (0.00)
Posted by PeterP on 2006-06-13, 14:50:50 (172.147.49.129)
Not a real answer, but (greatly simplified) since the major load will be constant current the droop on the last cap will be: I=C (dV/dT) If you look at 20mA, 10uF, and 1/120 seconds you'll get ~17Vpp .......
160: Tube DIY Asylum, On the lighter side. (0.00)
Posted by PeterP on 2006-06-13, 13:00:29 (172.147.49.129)
I've finished (for now) my 6SN7 headphone amp. It's like an Aikido/EarMax WOT. All I can say is that I really like it and have managed to fall asleep with it for the past two nights. I also started a .......
161: Tube DIY Asylum, Like I always say..... (0.00)
Posted by PeterP on 2006-06-13, 10:13:47 (205.188.116.66)
....I may be sick, but I know what I like. You're one disturbed individual. I like that. Pete. .......
162: Bottlehead Forum, Re: New Back Loaded Horns (0.00)
Posted by PeterP on 2006-06-12, 23:22:01 (64.12.116.131)
Great work! Can't wait for the review. Pete. .......
163: Tube DIY Asylum, Re: Sensitivity of a 6SN7/EL34 SET amp (0.00)
Posted by PeterP on 2006-06-12, 19:30:54 (64.12.116.131)
If you insist upon staying with the 6SN7, you just won't get there with just one stage. I'm sure that there are lots more out there but, take a look at: http://www.angela.com/catalog/how-to/300B.Schem .......
164: Tube DIY Asylum, Re: would there be sonic differences if (0.00)
Posted by PeterP on 2006-06-12, 13:33:01 (172.147.49.129)
The short answer.....yes. Does the rest of your system have the resolution to actually hear the difference? Is it a change for the better? That's another story. Are these the same type and matched? Ar .......
165: Bottlehead Forum, Re: The Circuit: Just a thought. (0.00)
Posted by PeterP on 2006-06-07, 11:28:58 (152.163.101.6)
Since you have the passive pre why not simply put your "hot" source into the passive pre and out to your Foreplay? Adjust the passive pre until your happy with the match, remove the passive pre and me .......
166: Bottlehead Forum, Also keep in mind that................... (0.00)
Posted by PeterP on 2006-06-07, 08:05:02 (152.163.101.6)
....if the new pot is 100K and the existing VC is 100K you can only get about -6dB attenuation max. and if the new pot is an audio (log) type, at the mid position you'll only be at about -2dB. Dependi .......
167: Bottlehead Forum, Re: Dumbfounded Or Just Dumb! (0.00)
Posted by PeterP on 2006-06-07, 07:53:12 (152.163.101.6)
Assuming input - wiper - pot end - existing VC Check to see that the new pot adds to the existing VC. Measure input to circuit ground. If the existing VC is also 100K the input should be adjustable fr .......
168: Bottlehead Forum, Re: Dumbfounded Or Just Dumb! (0.00)
Posted by PeterP on 2006-06-06, 19:11:18 (64.12.116.131)
Really stupid questions. Did you check the input to ground to verify that you are indeed adding up to 100K to the input impedance? What type of input VC configuration do you have? If it is a shunt con .......
169: Tube DIY Asylum, Re: Resistor Wattage Rating Question (0.00)
Posted by PeterP on 2006-06-06, 18:55:58 (64.12.116.131)
Finally, 20+ years in military electronics pays off ;^) 0.5W 350V See: http://www.dscc.dla.mil/Downloads/MilSpec/Docs/MIL-R-10509/mil10509.pdf Take care. Pete. .......
170: Tube DIY Asylum, Re: http://www.mcmaster.com/......I'll second that! (0.00)
Posted by PeterP on 2006-06-05, 20:50:03 (172.132.168.109)
They have a good selection of hardware, including brass, and on several occasions I've gotten "same day" service. Pete. .......
171: Tube DIY Asylum, Sorry, I can't help but ask! (0.00)
Posted by PeterP on 2006-06-05, 10:53:47 (205.188.116.66)
So, being a fan of the 76 you know that the output impedance would be on the high side for a preamp. What do you suggest for a solution? OT Cathode Follower White Follower Cathode Follower w/ CSS etc. .......
172: Tube DIY Asylum, Re: "Serious Stereo" .... on Power Supplies, DCR and Inductance (0.00)
Posted by PeterP on 2006-06-04, 14:34:02 (172.132.168.109)
"Yep, ALPS, PEC,etc was used in the passive design. No passive designs for me so far." I used to feel the same way. Then I tried using lower resistance pots. If your source can handle it, try going to .......
173: DIY HiFi Forum, Re: Ella Possible High Pitched Feedback....Any progress? (0.00)
Posted by PeterP on 2006-05-30, 18:55:46 (152.163.101.6)
Brian D offers good advice. See if the problem follows any of the tubes and try to eliminate any external causes first. What is the total setup? Sources, preamp etc. Pete. .......
174: Tube DIY Asylum, Re: help in adjusting Vout in the power supply of the "Brute force in a line stage" by Eric Barbour? (0.00)
Posted by PeterP on 2006-05-30, 10:01:57 (172.170.74.215)
Is this what you are looking at? http://headwize.com/images/barbour3.gif If so you are correct in that the output voltage is set by the zener diodes (plus the grid-cathode voltage of the output tube). .......
175: DIY HiFi Forum, Re: ella hum revisited (0.00)
Posted by PeterP on 2006-05-29, 17:05:25 (172.170.74.215)
I haven't made that comparison, however I would suspect that you would notice a little more detail in the upper mid range and an over improvement in the highs. Depending upon what you listen to, you m .......
176: DIY HiFi Forum, Re: ella hum revisited (0.00)
Posted by PeterP on 2006-05-28, 16:48:35 (172.170.74.215)
Great! Now you can sit back and enjoy what you've done. There's still plenty of things for you to try. When the time comes that you want to try something a little different, you can always try the sim .......
177: Tube DIY Asylum, Re: Sort of, but not really. (0.00)
Posted by PeterP on 2006-05-26, 21:25:58 (64.12.116.131)
You do understand. Even after doing this for over 25 years, I find the written word sometimes misleading and all too often I don't explain it just right. I was just concerned with your statement about .......
178: DIY HiFi Forum, Re: ella hum revisited (0.00)
Posted by PeterP on 2006-05-26, 19:49:59 (64.12.116.131)
Hi, I'm back from AOL hell! My DSL went to speeds of 7K (almost 1/10 the speed of dial-up), and after 3 DSL modems (thanks to the wizards at AOL) Verizon seems to have fixed the problem with my line. .......
179: Tube DIY Asylum, Re: Sort of, but not really. (0.00)
Posted by PeterP on 2006-05-26, 19:33:44 (64.12.116.131)
A choke reacts to current much like a capacitor does to voltage. Check out http://230nsc1.phy-astr.gsu.edu/hbase/electric/indtra.html They explain it better than I can. .......
180: Bottlehead Forum, Re: Enhanced FPIII photo.. The Guts (0.00)
Posted by PeterP on 2006-05-18, 08:38:30 (172.162.44.165)
Crowded yes, but nicely done. Great work. Pete. .......
181: Tube DIY Asylum, Re: Paul.....if I may ask. (0.00)
Posted by PeterP on 2006-05-15, 04:38:06 (205.188.116.66)
Thanks for the reply. I was actually thinking along the same lines. 76 choke loaded directly coupled 46 IT 211 ? OT. This will most likely end up as a winter project so I've lots of time to think abou .......
182: Bottlehead Forum, Re: Triple Orgasm is complete (or nearly so) (0.00)
Posted by PeterP on 2006-05-11, 21:05:55 (172.167.138.15)
WOW! A Bottlehead integrated amp. Very, very nice. .......
183: Bottlehead Forum, Re: Woodie Pic Gallery (0.00)
Posted by PeterP on 2006-05-11, 21:03:31 (172.167.138.15)
Magnificent work! I especially like the front plate treatment. Am I going blind though? I see what looks like a volume control on top but nothing underneath. Future use? .....And I'm sure it sounds as .......
184: Tube DIY Asylum, Paul.....if I may ask. (0.00)
Posted by PeterP on 2006-05-11, 12:08:08 (205.188.116.66)
I know that you are a fan of the 211 (including paralleled 211's), would you mind sharing your favorite 211 amp schematic? I know that there is a 211 in my future and before I try something silly like .......
185: Tube DIY Asylum, Re: My new 300b.......... (0.00)
Posted by PeterP on 2006-05-11, 07:45:10 (64.12.116.131)
Very nice! Please tell me more about the Plitron OT. Which did you choose? 5K, 3K? How was their delivery? Can you compare it to any other OT's that you've used? What's your initial impression? I'm se .......
186: SET Asylum, Oh that amp. (0.00)
Posted by PeterP on 2006-05-09, 06:01:14 (172.145.88.140)
On the last day of the show, the last room I went to was Robin Wyatts. The Lams were quite good but ..... Oh that amp. I was totally taken by the 50's in that amp. The bass extention of 300B's, mids l .......
187: Tube DIY Asylum, Now, if I could only find.......... (0.00)
Posted by PeterP on 2006-05-05, 09:03:15 (172.135.19.76)
different size branding irons with Power, Volume, Phones, Input, etc. ;^) Actually, I'll be building two more for people that heard the breadboard and am thinking about laser engraving. Don't know how .......
188: Tube DIY Asylum, Re: choke in ground leg of power supply (0.00)
Posted by PeterP on 2006-05-05, 06:50:38 (172.135.19.76)
The switching power supply folks have been doing exactly that for the past 30 years. When using large stud mounted diodes the case can be kept at a constant voltage (with respect to ground) and the in .......
189: Tube DIY Asylum, Re: I completed my amp! (0.00)
Posted by PeterP on 2006-05-05, 04:27:24 (172.144.219.56)
I guess that you've done the woodwork once or twice before ;^) I've got to get better woodworking skills (and tools). And tell me you made the volume control knob. Great work. .......
190: Tube DIY Asylum, Headphone amp almost there. (0.00)
Posted by PeterP on 2006-05-04, 21:17:41 (172.144.219.56)
I'm just about ready to start the final wiring and wanted to share the pictures of the "final" fit check. http://www.flickr.com/photos/11354289@N00/sets/72057594125874646/ The top plate is a slat from .......
191: Bottlehead Forum, I'll second the PECs (0.00)
Posted by PeterP on 2006-05-04, 05:29:26 (152.163.101.6)
But only for dual mono. Check out my post: http://db.audioasylum.com/cgi/m.mpl?forum=tubediy&n=89407&highlight=PEC+peterp&r=&session= The PECs do have more of a tracking problem than the others that I .......
192: Tube DIY Asylum, Re: Cap for OTL headphone amp. (0.00)
Posted by PeterP on 2006-04-21, 07:25:52 (172.166.103.37)
Well that won't be small. :^( Since this is the output from a White Follower, an electrolytic will work but the question is will it sound good. Maybe a JJ or BG (can type) might be OK....anything smal .......
193: Tube DIY Asylum, Cap for OTL headphone amp. (0.00)
Posted by PeterP on 2006-04-20, 20:53:05 (172.130.51.128)
So now I want to try my hand at an OTL Headphone amp. Any suggestions for the output cap? It will need to be >250uF and >250Vdc. Since this is going to be as small as possible, space is at a premium. .......
194: DIY HiFi Forum, Re: One step at a time. (0.00)
Posted by PeterP on 2006-04-17, 10:00:11 (64.241.37.140)
I haven't abandoned you. My home computer has a virus so I'm using a laptop on a different network. The feedback that I'm referring to is the small gauge wires connected to the output transformer or o .......
195: Bottlehead Forum, Possibly........ (0.00)
Posted by PeterP on 2006-04-11, 11:43:21 (172.164.203.223)
....the cleanest system I've ever seen. Fantastic work! Pete. .......
196: Tube DIY Asylum, A quick trip to eBay (0.00)
Posted by PeterP on 2006-04-11, 06:48:48 (172.164.203.223)
....and look what I found. http://cgi.ebay.com/30-C-D-TWU-VITAMIN-Q-TYPE-CAPACITOR-056uf-100V-NOS_W0QQitemZ7608543005QQcategoryZ4662QQssPageNameZWDVWQQrdZ1QQcmdZViewItem That should answer your questi .......
197: Tube DIY Asylum, Re: Acrosound push pull parallel amplifier DIY (0.00)
Posted by PeterP on 2006-04-11, 06:38:45 (172.172.95.12)
The "X" connection is used to simply provide a DC bias for the heater voltage. This way the AC heater voltage is raised ~ +40V which will reduce heater induced hum in the first stage and keep to withi .......
198: Tube DIY Asylum, Re: How about identifying these? (pic) (0.00)
Posted by PeterP on 2006-04-11, 06:03:03 (172.164.203.223)
I believe that the C-D is Cornell Dubilier. www.cde.com Looks like a film type? Any other markings? The CDE site can be a PITA to find info if you don't know the type you're looking for. Good luck. Pe .......
199: DIY HiFi Forum, Re: One step at a time. (0.00)
Posted by PeterP on 2006-04-11, 05:11:35 (172.164.203.223)
Seems to me that your power tubes are fine and I don't remember what the B+ dropped down to (seems a little low but not too much it's less than 10%). As long as the current through the power tubes rem .......
200: Bottlehead Forum, Re: Enhanced FPIII Base & Plate (0.00)
Posted by PeterP on 2006-04-09, 22:18:01 (172.164.203.223)
That is really looking nice. Absolutely beautiful. Can't wait to see the finished product. Have fun. Pete. If I could only find a drill for those square holes ;^) .......
201: DIY HiFi Forum, Re: One step at a time. (0.00)
Posted by PeterP on 2006-04-08, 17:51:44 (172.164.203.223)
IIRC the .47uF caps are part of the phase splitter. All you need to do is to remove the (4) 0.1uF caps. That is as low as you should expect the hum to be. This hum could be due to a couple of things s .......
202: DIY HiFi Forum, Re: One step at a time. (0.00)
Posted by PeterP on 2006-04-08, 17:21:33 (172.164.203.223)
.....and when you do short them to ground you should: 1. Remove the wires from the volume control (at the PWB) 2. Solder in a jumper to short the inputs right at the PWB 3. Do you still have hum? And .......
203: Tube DIY Asylum, Re: Cap Voltage Rating Question - Don't do it. (0.00)
Posted by PeterP on 2006-04-06, 12:39:59 (172.164.109.57)
If your line increases by 3% you'll be over the rated voltage of the cap. You need at least a 400VDC (should be 450VDC or greater) rated working voltage cap. Would your 350V cap work? Yes, however in .......
204: Tube DIY Asylum, Re: bridge rectifiers and CT transformers (0.00)
Posted by PeterP on 2006-04-05, 15:43:21 (172.164.109.57)
Using a tube for the B+ and SS for the neg bias has the added bonus of ensuring the neg bias is up before the B+. At least for the initial turn-on and provided that there is not a large RC time consta .......
205: Tube DIY Asylum, Re-reading what you had to say. (0.00)
Posted by PeterP on 2006-04-05, 12:56:08 (172.164.109.57)
When you said: "If you hang a negative bridge and a positive bridge off the same winding..." If you are referring to truly just an isolated single winding without a center tap and 2 full wave bridges .......
206: Tube DIY Asylum, Re: I can't see how that contradicts my assertion (0.00)
Posted by PeterP on 2006-04-04, 21:41:13 (172.164.109.57)
It's just a way of getting a neg bias from the same winding. As to your exact scenario. Are you referring to using 4 diodes in a full wave bridge with the transformer CT as ground? Pete. .......
207: Tube DIY Asylum, Not entirely true. (0.00)
Posted by PeterP on 2006-04-04, 20:06:59 (172.164.109.57)
While I certainly don't condone the practice you can develop a small amount of negative bias. Take a look at: http://www.triodeel.com/dynawil1.gif It does work, but for the price of a small transforme .......
208: Tube DIY Asylum, Re: Double the currents....... (0.00)
Posted by PeterP on 2006-04-04, 10:36:30 (172.163.208.53)
Exactly what I did. When I first turned this on I found the current in the buffer/parafeed driver stage to be too low. Since the 660 ohms was really two 330 resistors (What was I thinking??!!) I simpl .......
209: Tube DIY Asylum, Re: How do I paste a picture into a message? (0.00)
Posted by PeterP on 2006-04-03, 22:15:33 (172.163.208.53)
Go to a picture hosting site like: http://www.imagestation.com I'm sure there are lots of others. Then upload the picture. Once it's hosted, you can link to it using the Optional Image URL: ie: http:/ .......
210: Tube DIY Asylum, Re: Am I being seduced by the dark side? (long) (0.00)
Posted by PeterP on 2006-04-03, 21:49:29 (172.163.208.53)
Sure, I'm always open to looking at new schematics. Feel free to email me at: --php289@aol.com-- (remove the --) Thanks. Pete. .......
211: Tube DIY Asylum, Am I being seduced by the dark side? (long) (0.00)
Posted by PeterP on 2006-04-03, 20:20:15 (172.163.208.53)
I've never been a big fan of the 6SN7. Liked it as a driver but not as an amp, it always sounded too tubey for my tastes. Well I just simply plugged a 6SN7 directly into the 6SL7 SRPP socket in my hea .......
212: Tube DIY Asylum, Re: 6DJ8 SRPP Line Stage (0.00)
Posted by PeterP on 2006-04-03, 19:57:40 (172.163.208.53)
Glad to hear that things worked out. Do you have any measured specs. Gain? Low freq? High freq? What amp are you driving? So many questions, but from that short read, I'm tempted to try this myself. A .......
213: Tube DIY Asylum, Re: 6DJ8 SRPP Line Stage (0.00)
Posted by PeterP on 2006-04-03, 16:07:48 (64.241.37.140)
I haven't used this tube however it looks like it should be quite good. If you haven't already seen it: http://store.electron-valve.com/suof6dforau.html makes for an interesting read. Maybe you should .......
214: Tube DIY Asylum, Re: Buzz in Homemade Preamp (0.00)
Posted by PeterP on 2006-04-02, 21:11:37 (172.163.208.53)
I can't really say since I'm using them as separate left and right controls. Although, I would say better than the Radio Shack from my short time using them as stereo. They must have their trade-offs .......
215: Tube DIY Asylum, Re: Buzz in Homemade Preamp (0.00)
Posted by PeterP on 2006-04-02, 20:12:26 (172.163.208.53)
Precision Electronic Components. The KKA series is a dual log tapered (stereo audio) pot. I got mine from Digikey. http://dkc3.digikey.com/PDF/T061/1283.pdf Do a quick search here for PEC and you will .......
216: Tube DIY Asylum, Re: Buzz in Homemade Preamp (0.00)
Posted by PeterP on 2006-04-02, 17:38:50 (172.163.208.53)
I've used the RS pots several times now without problem. I agree with 2wo that the pot should be grounded. This should be done will all exposed metal if only for a safety issue. It seems odd that the .......
217: Tube DIY Asylum, Re: Anyone filtering AC heater voltage? (0.00)
Posted by PeterP on 2006-03-31, 19:29:08 (172.130.227.198)
Check my response to arend-jan. I used a 2K1. It seems to have lowered the noise floor without changing any of the sonics. In this open breadboard, it is clearly quieter. I can now remove the ground t .......
218: Tube DIY Asylum, Re: Anyone filtering AC heater voltage? (0.00)
Posted by PeterP on 2006-03-31, 05:49:33 (172.136.209.246)
It's an old one I had knocking around. Markings are: 2K1 2A, 115/250V 50-400Hz Since I am using SRPP I need to float the heater voltage at ~75Vdc to stay within the heater-cathode rating. The case of .......
219: Tube DIY Asylum, Anyone filtering AC heater voltage? (0.00)
Posted by PeterP on 2006-03-31, 05:14:12 (172.136.209.246)
I just added a Corcom line filter to the heaters of my headphone amp (Yes, the 6.3Vac). It took the background noise to a new level (In a good way.). What I find most interesting is that, if I simply .......
220: Tube DIY Asylum, I'll have to give that a try. (0.00)
Posted by PeterP on 2006-03-30, 09:22:47 (172.136.209.246)
Next up will be a headphone amp with 99.99% silver for the signal wires and ground bus. We'll see how that works out. .......
221: Tube DIY Asylum, Re: line stage ? (0.00)
Posted by PeterP on 2006-03-29, 19:18:35 (172.136.209.246)
I'll second that. Check out: http://db.audioasylum.com/cgi/m.mpl?forum=tubediy&n=89407&highlight=passive+peterp&r=&session= I spent more time and money on the box than the electrical parts ;^) If you .......
222: Bottlehead Forum, Re: Soon To Be Greater NYC Group is in!! (0.00)
Posted by PeterP on 2006-03-29, 18:57:38 (172.136.209.246)
Very, very nice. Now I'll have to make sure that I make it to one of your NYC meets even if it's just to see your new FPIII. Pete. .......
223: Tube DIY Asylum, Re: Wire Size recommentations for tube Amps? (0.00)
Posted by PeterP on 2006-03-29, 18:11:54 (172.136.209.246)
People will agree and disagree as to use copper or silver wire, teflon or PVC insulation etc. I like copper/teflon for power and I am just starting to play with silver for signal wiring. Although not .......
224: Tube DIY Asylum, Re: Dynaco MKIII Tube Recommendation (0.00)
Posted by PeterP on 2006-03-29, 05:04:07 (172.137.24.168)
I can only compare Sovtek EL34, JJ KT88, and Ei90 (MKii and MKiii) and all of this was done about 4 years ago. EL34 .....UL.......OK .....Triode...Better, but again just OK KT88 .....UL.......Good ove .......
225: Bottlehead Forum, Re: Titled: Why I don't like my Bottlehead gear or I drank the KoolAid and love it. (0.00)
Posted by PeterP on 2006-03-28, 15:30:21 (172.134.186.141)
Well, you could keep another set of speakers to switch over to for those poor recordings. It doesn't need to be a set of Bose, a nice Pioneer 8" full-ranger (0.75 - 1 cu. ft. sealed) and RatShack twee .......
226: Tube DIY Asylum, Welcome to my world. (0.00)
Posted by PeterP on 2006-03-27, 16:58:22 (64.241.37.140)
I have two boys, 13 and 16. Both could care less and rather listen to their iPods. My only hope is the 16 year old. He at least can distinguish the difference. However he just doesn't care. I use him .......
227: DIY HiFi Forum, One step at a time. (0.00)
Posted by PeterP on 2006-03-27, 16:16:09 (64.241.37.140)
You need to find out what stage is causing the hum. Is this the point-to-point wiring or PC board type Ella? In any case you should follow a method. You need to find out what stage is causing the hum. .......
228: Bottlehead Forum, Re: SEXy vs. BK-16 (0.00)
Posted by PeterP on 2006-03-25, 14:57:30 (172.162.249.35)
What about the Fostex recommended enclosure for the FE107E - (3) per box? I've never heard it but I do have FE107E in a 6L dual ported box and I like them very much. Not much low end ( http://www.fost .......
229: Bottlehead Forum, Re: OT: Prayers, good karma, positive waves (0.00)
Posted by PeterP on 2006-03-24, 08:26:04 (172.162.249.35)
I met Bill at one of your Bots. As I recall he was headed for Okinawa at the time. He will be in my thoughts and prayers. Take care. Pete. .......
230: Tube DIY Asylum, Re: My 2A3 amp ticks! (0.00)
Posted by PeterP on 2006-03-23, 09:02:21 (172.128.36.47)
I also had a problem with thermal expansion making a "ticking" sound. In my case it was a batch of type 46 tubes. If all else is working properly, try running the amp for an extended period of time an .......
231: Bottlehead Forum, Sansui (0.00)
Posted by PeterP on 2006-03-21, 15:38:51 (172.128.36.47)
I've always liked the look of that Sansui tuner. How did it sound? Thanks, Pete. .......
232: Tube DIY Asylum, So simple yet so good. (0.00)
Posted by PeterP on 2006-03-21, 08:31:16 (172.128.36.47)
Check out the schematic of my new headphone amp. Just got it up and running and, so far so good. http://www.imagestation.com/picture/sraid202/p0e8b8223f9ecc95cacc01f5fe66f5a0d/efc28370.jpg Very simple .......
233: Tube DIY Asylum, Re: 45 tube B+ question...HELP! (0.00)
Posted by PeterP on 2006-03-20, 17:08:17 (64.241.37.140)
What's the voltage across the 1.35K cathode resistor? The 275V spec is the voltage at the plate with respect to the cathode. With ~310V on the plate with respect to ground, I suspect that you are just .......
234: Tube DIY Asylum, Quite true. (0.00)
Posted by PeterP on 2006-03-20, 15:47:44 (64.241.37.140)
With a 6SN7 I would expect the input capacitance to be less than half that (~110 uuF) including the socket. The point is to simply be aware of how the source impedance can affect the sound. I would th .......
235: Tube DIY Asylum, Re: example (0.00)
Posted by PeterP on 2006-03-20, 13:21:43 (172.128.36.47)
You're right. The source impedance, as far as the input tube is concerned, varies all over the place. Roughly from 0 to 1/2 of the input volume pot. This why cross-feed circuits need to be after the f .......
236: Tube DIY Asylum, oops (0.00)
Posted by PeterP on 2006-03-14, 06:45:56 (172.169.69.53)
I should wake-up first. "Even if the FET has a gate threshold of 2.5V then the pot will need to be adjusted to about 100 ohms to get ~30mA." SHOULD BE Even if the FET has a gate threshold of 2.5V then .......
237: Tube DIY Asylum, Re: This would appear tobe quite similar to my PP-1C circuit... (0.00)
Posted by PeterP on 2006-03-14, 05:11:09 (152.163.101.6)
To see the schematic you need to register and log-in at diyaudio.com You may want to try another place to host your pics that doesn't require you to log-in. Have fun. Pete. .......
238: Tube DIY Asylum, Re: This would appear tobe quite similar to my PP-1C circuit... (0.00)
Posted by PeterP on 2006-03-14, 05:07:04 (152.163.101.6)
Allen, The CCS will function. An enhancement MOS FET will work as a CCS in much the same way a bipolar transistor will work (a la Bottlehead ) however, as you pointed out the gate voltage is way too l .......
239: Tube DIY Asylum, That's not it, but thank you. (nt) (0.00)
Posted by PeterP on 2006-03-09, 07:34:35 (172.135.44.204)
nt. .......
240: Tube DIY Asylum, Re: Paraphase splitter - why is it unpopular? (0.00)
Posted by PeterP on 2006-03-08, 06:22:49 (172.135.44.204)
It's OK. While I was setting up my 6EM7 PP I started out with a paraphase circuit. I actually prefer it when listening to computer (.mp3) music. There seems to me to be some distortion in the higher f .......
241: Tube DIY Asylum, OT Where did I see that? (0.00)
Posted by PeterP on 2006-03-08, 06:10:23 (172.135.44.204)
Due to a recent hard disk crash I've lost all my bookmarks. Somewhere on the web is a site that has sound clips that have different levels of odd and even harmonic distortion. If I remember right, you .......
242: Tube DIY Asylum, Selector Switch Suggestions. (0.00)
Posted by PeterP on 2006-03-08, 06:02:53 (172.135.44.204)
So, in the past, I've used toggles and rotory switches for input selector switches now I would like a DPDT rocker switch that will offer the same performance. To make it easy to mount, I would also li .......
243: Tube DIY Asylum, Not all of us.... (0.00)
Posted by PeterP on 2006-02-28, 13:49:04 (172.169.255.139)
...are like that. I've been an EE for the past 26 years and a tech for 9 years prior to that. (That's right I'm an old fart.) I learned very quickly that, in audio, you need to make the final decision .......
244: Tube DIY Asylum, OT. Don't let this happen to you! (0.00)
Posted by PeterP on 2006-02-28, 07:55:35 (172.169.255.139)
I always tell anyone who asks..."Back-up your data." Well I'm finally almost back together after a hard disk crash. You know it. I didn't back-up a single thing. I will say that Dell was very good at .......
245: Bottlehead Forum, JT, best wishes and get well soon. (nt) (0.00)
Posted by PeterP on 2006-02-13, 12:04:58 (172.172.104.37)
nt .......
246: Tube DIY Asylum, Re: need tips for soldering the tabs on small tube sockets (0.00)
Posted by PeterP on 2006-02-02, 19:23:52 (172.172.23.84)
For the smaller sockets, components, and even some PCB work I like to use the 40W iron. I take a new tip and turn it down to less than 1/2" it's diameter for about the first 1/4" to 3/8". The new "thi .......
247: Tube DIY Asylum, Re: How good are bench power supplies for filaments? (0.00)
Posted by PeterP on 2006-01-31, 19:20:45 (172.172.23.84)
Just a word of caution. "Bench" supplies (especially switchers) often have output caps to chassis ground (from the + and - outputs). In may supplies these caps have a rating of 100V or less. Be certai .......
248: Tube DIY Asylum, Re: Using rectifier heater voltage for Stand By? (0.00)
Posted by PeterP on 2006-01-31, 18:53:54 (172.172.23.84)
I agree that it is far better to control the line voltage going to separate transformers. However, in this amp, size is a real constraint and at first blush I thought that because I use the relay to l .......
249: Tube DIY Asylum, Using rectifier heater voltage for Stand By? (0.00)
Posted by PeterP on 2006-01-31, 12:47:56 (172.172.23.84)
Is it OK to use a relay to control the heater voltage of a 5U4G with 400Vrms on each plate? Aside from the precautions for the relay itself (current rating, contact to contact and contact to coil volt .......
250: Tube DIY Asylum, Re: safety fuse (0.00)
Posted by PeterP on 2006-01-30, 11:05:08 (64.12.116.131)
The primary purpose of a fuse is to prevent damage. This usually means that it protects the wiring from burning and fusing. The secondary purpose is to safely remove an overloaded circuit from the pow .......
251: Tube DIY Asylum, Re: It is not a matter of being "more flexible". (0.00)
Posted by PeterP on 2006-01-30, 10:38:35 (64.12.116.131)
"It is OK for iner-wiring sleeving." Exactly. That's my main reason for asking. The typical teflon tube is just too stiff for internal wiring. I've resorted to stripping teflon jacketed copper wire ju .......
252: Tube DIY Asylum, Re: Wire sleeving. (0.00)
Posted by PeterP on 2006-01-30, 04:08:10 (172.158.92.230)
A bit misleading. The 1/4" would be for over 2 #16AWG each in its own 1/8" teflon tube. Thanks, I'll contact you. Pete. .......
253: Tube DIY Asylum, Wire sleeving. (0.00)
Posted by PeterP on 2006-01-29, 20:02:03 (172.158.92.230)
Lately I've been trying different types of wire and I must admit that I am leaning towards silver. Can anyone suggest a source for cotton or silk braid to cover the bare wire? (maybe even silk over co .......
254: Cable Asylum, Spades vs Bananas (0.00)
Posted by PeterP on 2006-01-24, 10:23:50 (172.161.203.129)
I've always used spade lugs or bare wire for speaker terminations. So before I buy some WBTs I'd like to get a few opinions. When it comes to speaker cable terminations, what's your preference and why .......
255: Tube DIY Asylum, Re: PP design--Thanks (0.00)
Posted by PeterP on 2006-01-20, 21:42:00 (64.12.116.131)
If I may suggest. Here is my 6EM7 PP. I listen to it evey day and it works just fine for me. http://www.geocities.com/remlapretep/php_audio.htm It's been to a few Bottlehead meets so you could ask abo .......
256: Tube DIY Asylum, Re: Pete, can you explain the reason (0.00)
Posted by PeterP on 2006-01-20, 06:32:31 (172.161.203.129)
Never gave it much thought before. All I know is that I had a screen supply that used a 6X5 with a LCLC (30H/32uF/30H/32uF) which had an audible buzz. When I added .22-.47uF the buzz was gone. Must ha .......
257: Tube DIY Asylum, Re: 6x4 buzzing in 5687 simple pre (0.00)
Posted by PeterP on 2006-01-19, 07:25:17 (64.12.116.131)
I take it that you are using the LCLC power supply. If that's the case, you may want to try a small cap right after the 6X4 and before the first choke. Try something like 1uF and smaller. Take care, P .......
258: Tube DIY Asylum, Re: Fisher restoration - need assistance (0.00)
Posted by PeterP on 2006-01-13, 05:06:40 (64.12.116.131)
Now that Dave has posted the schematic, if you still want to replace the pot with a resistor, you should: 1. Get two matched 100K resistors 2. Remove R75 and R76 3. Wire one 100K resistor from pin 3 t .......
259: Tube DIY Asylum, What Dave said. (0.00)
Posted by PeterP on 2006-01-11, 13:27:40 (172.152.214.211)
I should have read his post first. Next time. .......
260: Tube DIY Asylum, Re: Agree (0.00)
Posted by PeterP on 2006-01-11, 13:24:34 (172.152.214.211)
Without seeing the schematic it is difficult to say. There should be a resistor from pin 1 of the tube to some high voltage. Typically that same value (matched as close as possible) is used from pin 3 .......
261: Tube DIY Asylum, Just two things to keep in mind. (0.00)
Posted by PeterP on 2006-01-11, 10:39:06 (172.152.214.211)
It all works, you just have to make sure that the parts are up to the task. As for switching the high voltage AC....First, unless you are using a full wave diode bridge (4 diodes) you are still switch .......
262: Tube DIY Asylum, Re: You are "restoring" or "rebuildinng" the amp? (nt) (0.00)
Posted by PeterP on 2006-01-11, 09:04:45 (172.152.214.211)
I think what cheap-Jack is eluding to is that there is difference between "restoring" and "rebuilding". You stated that: "I am willing to make improvements to the circuit if they do not require me to .......
263: Bottlehead Forum, My condolences Doc. (nt) (0.00)
Posted by PeterP on 2006-01-10, 08:43:49 (172.152.214.211)
. .......
264: Tube DIY Asylum, Quiet Transformer (0.00)
Posted by PeterP on 2006-01-10, 05:54:15 (172.152.214.211)
I'm looking for a dead quiet transformer for 6.3Vac ~4A (actual load ~2A). I was thinking about the Hammond 167N6. Has anyone used these? Without any other info, I may try some toroids instead. Thanks .......
265: Bottlehead Forum, Re: Cruising the CES Website.....I found... iPo-duction? (0.00)
Posted by PeterP on 2006-01-09, 19:38:47 (152.163.100.7)
And how about this one at the show? http://www.audiofederation.com/hifiing/2006/CES2006/day1/IMG_8484.jpg .......
266: Tube DIY Asylum, Re: General question about power transformers (0.00)
Posted by PeterP on 2006-01-09, 08:10:59 (172.152.214.211)
The main advantage of seperate transformers is that it is much easier for you to warm up your tubes and avoid cathode stripping. If you intend to have a turn-on delay or standy-by circuit to allow you .......
267: Tube DIY Asylum, ...and what he said again. (0.00)
Posted by PeterP on 2006-01-08, 19:05:24 (172.152.214.211)
I strongly agree. The 2XX series is fine for breadboards and prototypes, but definitely not for a finished amp. I tried several and all the ones that I tried have unacceptable mechanical hum. If you a .......
268: Tube DIY Asylum, Tube Center to Center. (0.00)
Posted by PeterP on 2006-01-05, 16:48:27 (172.152.214.211)
I'm looking at making a small EL84 PP (looking for about 10W). How close can these tubes be placed to each other (center to center)? I've always tried to keep atleast 3" for KT88 and use 2" for my 6EM .......
269: High Efficiency Speaker Asylum, Re: Fostex FE 107E (0.00)
Posted by PeterP on 2005-12-23, 05:45:07 (152.163.100.7)
http://www.geocities.com/remlapretep/104_0452.JPG This is my new favorite speaker. I started on Godzilla’s site and ended up drawing my own plans. It was at the most recent NJ Bottlehead meet so you m .......
270: DIY HiFi Forum, Re: Ella with pre-amp (0.00)
Posted by PeterP on 2005-12-12, 07:01:43 (172.158.114.23)
What you are doing is padding down the input of the amp. Will this work? Absolutely. For some guidance you might want to check out VoltSecond's site (linked from the Bottlehead home page). I don't kno .......
271: High Efficiency Speaker Asylum, Bass Puzzle (0.00)
Posted by PeterP on 2005-12-12, 05:24:08 (152.163.100.7)
I tried this over on the Speaker Asylum and got no replies so I thought I'd try here. I’m looking to make a DIY bass speaker given the following restrictions. 1. Bass to match up with Fostex FE107E ~9 .......
272: Speaker Asylum, Bass Puzzle (0.00)
Posted by PeterP on 2005-12-08, 07:45:23 (205.188.116.7)
I’m looking to make a DIY bass speaker given the following restrictions. 1. Bass to match up with Fostex FE107E ~90dB/W/m 2. No bi-amping. Must match-up with Fostex using passive xo. 3. xo to be 400 – .......
273: Tube DIY Asylum, Re: I agree & disagree. (0.00)
Posted by PeterP on 2005-12-07, 13:03:03 (205.188.116.7)
Maybe I wasn't clear enough. I abandoned bi-amping my system after just a few months. I am currently bi-wired using a single amp and loving it. Thanks for the added power cord info. Pete. Next OT ---- .......
274: Tube DIY Asylum, Re: Cables here is off topic. But... (0.00)
Posted by PeterP on 2005-12-07, 10:57:46 (205.188.116.7)
"Tell us how it sound sonically." For most music there really doesn't seem to be much of a difference over good OFC. However, as in the case with JT, there are some recordings that now have a much bet .......
275: Tube DIY Asylum, OT Speaker cables (again) (0.00)
Posted by PeterP on 2005-12-07, 06:28:38 (172.137.117.88)
I don’t want to start a cable pissing contest but here’s my little story. My cable odyssey started back in 1972. I was stationed at a LORAN station in N. California. With my stereo turned off, you cou .......
276: Bottlehead Forum, Does this drive anyone else crazy? (0.00)
Posted by PeterP on 2005-12-07, 04:57:57 (64.12.116.7)
Sheryl Crow in "Good is Good" sings: "And everytime you hear the rolling thunder You turn around before the lightening strikes" I like her music, I even like the song itself, but that just drives me n .......
277: Tube DIY Asylum, Exactly what I tried to say. (0.00)
Posted by PeterP on 2005-12-04, 18:45:15 (205.188.116.7)
"You want the motor run caps for audio." If it wasn't clear when I said: "I hope you mean motor run caps." That's exactly what I meant. The oil filled motor run caps are great for audio as PS caps, ca .......
278: Bottlehead Forum, Thanks again. (0.00)
Posted by PeterP on 2005-12-04, 11:21:46 (172.137.117.88)
Great time with more equipment then I've listened to in a long time. Just wish I had a chance to hear it all. Again thanks, Pete. .......
279: Tube DIY Asylum, Re: MP3 player to amplifier (0.00)
Posted by PeterP on 2005-12-02, 06:39:46 (152.163.100.7)
"6DS5, it's just a nice, cheap " I'll say! $0.60 at tubesandmore. I haven't heard this tube. You might want to consider using it in a version of: http://www.triodeel.com/compact.html I know that there .......
280: Tube DIY Asylum, Re: MP3 player to amplifier (0.00)
Posted by PeterP on 2005-12-01, 11:21:38 (152.163.100.7)
Most any amp will work. Just keep in mind that the output from the MP3 will not be as hot as from a CD player. All you really need is a cable to connect the headphone output to the amp. (Readily avail .......
281: Tube DIY Asylum, Motor run vs motor start caps. (0.00)
Posted by PeterP on 2005-12-01, 10:59:08 (152.163.100.7)
I hope you mean motor run caps. Motor start caps are not intended for continuous use. From: http://www.yorkcapacitor.com/support.html What is the difference between a motor start capacitor and a motor .......
282: Tube DIY Asylum, Re: Using an iPod as source to a Darling (0.00)
Posted by PeterP on 2005-11-29, 08:40:53 (152.163.100.7)
"Omit the resistor that is in the schematic from that tube's grid to ground." Just as a belt-and-suspenders kind of neurotic, might I suggest changing the value to ~500K instead. I like to have a resi .......
283: Tube DIY Asylum, Re: Using an iPod as source to a Darling (0.00)
Posted by PeterP on 2005-11-29, 06:12:05 (152.163.100.7)
My son has a RAVE MP3 player and it has just enough volume out of the headphone jack to play on my amp (~4W with 90dB/W/m speakers). I've also used my Palm Pilot (Tungsten T) as a source. Sound is OK. .......
284: Tube DIY Asylum, Re: I'm using SRPP too. (0.00)
Posted by PeterP on 2005-11-21, 11:06:21 (152.163.100.7)
I also find the 6SL7 SRPP clean and dynamic. That's what I like about it. May I suggest that, if your power supply is clean enough, you remove the 100uF cap and see how you like that. I find that, if .......
285: Tube DIY Asylum, .........and just one more thought. (0.00)
Posted by PeterP on 2005-11-21, 07:47:53 (152.163.100.7)
I forgot to mention, but you probably already know, that if you use SRPP you will need to float the heater voltage at about 75V to stay within the heater-cathode rating of the 6SL7. Enjoy, Pete. ::: T .......
286: Tube DIY Asylum, Re: Glory SET 45 Homebrew mods? (0.00)
Posted by PeterP on 2005-11-20, 20:19:37 (64.12.116.7)
I'm having a hard time reading the parts, however it looks like you're using a 6SN7 for the gain/driver. You may want to consider a 6SL7. Others my disagree, but I happen to like a 6SL7 SRPP. Run as c .......
287: High Efficiency Speaker Asylum, Jensen P15N ? (0.00)
Posted by PeterP on 2005-11-16, 07:07:08 (64.12.116.7)
Is this the one you mean? http://img3.musiciansfriend.com/dbase/pdf/spec/665014.pdf 15" Qts 1.18 Looks like it should do the job. Have you heard it on an OB? .......
288: Tube DIY Asylum, Re: Regarding your pictures....Like this? (0.00)
Posted by PeterP on 2005-11-03, 05:44:23 (172.174.97.218)
Thanks. I tried before but I guess that the pictures were too large. I resized them to 50% and it seem to work. Now, how do I post multiple pictures. I tried "space ," what works? I'm sure the directi .......
289: Tube DIY Asylum, Just looking to understand. (0.00)
Posted by PeterP on 2005-11-03, 05:09:55 (172.174.97.218)
"why ask why?" :) Even in this ultra-simple example there are multiple things that contribute to the overall sound. It would be nice to know which ones have the largest effect on what I'm hearing so .......
290: Tube DIY Asylum, Gentlemen (0.00)
Posted by PeterP on 2005-11-02, 15:46:30 (172.174.97.218)
First let me say that I am not unaccustomed to working with small and large gauge wire. I started using #30 AWG wire-wrap wire in my first amp and have continued to do so. I have been working in elect .......
291: High Efficiency Speaker Asylum, You are one sick........ (0.00)
Posted by PeterP on 2005-10-31, 18:35:21 (152.163.100.7)
I like that! If you do find something worth using, please post. Pete. "I may be sick, but I know what I like." .......
292: Tube DIY Asylum, Re: Passive PreAmp (Way too long) (0.00)
Posted by PeterP on 2005-10-31, 18:27:40 (152.163.100.7)
I didn't try this in shunt mode. Maybe I'm wrong, but I just didn't like the idea of the load changing in a passive pre and who knows what source I'll be using next. I like the idea of shunt mode in a .......
293: Tube DIY Asylum, Re: And a quick safety question. (0.00)
Posted by PeterP on 2005-10-31, 18:22:37 (152.163.100.7)
With the knobs tied to the circuit return, I get no noise at all. Without being tied to the circuit return, I only get noise (hum/buzz) when I touch the knobs. It is worst at maximum resistance (~3/4 .......
294: Tube DIY Asylum, Let's try these Pics. (0.00)
Posted by PeterP on 2005-10-31, 18:12:15 (152.163.100.7)
One more time. Try cut and paste. http://www.flickr.com/photos/11354289@N00/58301189/ http://www.flickr.com/photos/11354289@N00/58301190/ .......
295: Tube DIY Asylum, And a quick safety question. (0.00)
Posted by PeterP on 2005-10-31, 17:01:00 (64.12.116.7)
Since this is a passive pre there is no AC power cord to provide a safety ground. The metal knobs did pick-up some noise so I had to tie each one to its respective circuit return. This works fine but .......
296: Tube DIY Asylum, Passive PreAmp (Way too long) (0.00)
Posted by PeterP on 2005-10-31, 15:44:33 (172.174.97.218)
The pics are not very good and I need to figure out how to letter the box but. http://www.geocities.com/remlapretep/MPP-front.JPG http://www.geocities.com/remlapretep/MPP-rear.JPG In my home office sy .......
297: Tube DIY Asylum, I should look first. I see you did! (NT) (0.00)
Posted by PeterP on 2005-10-30, 11:21:28 (205.188.116.7)
Thanks. .......
298: Tube DIY Asylum, Please share. What did you find?. (NT) (0.00)
Posted by PeterP on 2005-10-30, 11:18:54 (205.188.116.7)
, .......
299: High Efficiency Speaker Asylum, Group Delay and Phase. Educate me please. (0.00)
Posted by PeterP on 2005-10-27, 08:16:44 (205.188.116.7)
I'm quite happy with the results that I'm hearing from my 6L FE107E speakers. Looking to expand on this I see, when using WinISD, that there is a considerable difference in the curves of the Group Del .......
300: High Efficiency Speaker Asylum, Re: Full / wide range suggestions wanted. (0.00)
Posted by PeterP on 2005-10-26, 21:14:42 (152.163.100.7)
http://www.geocities.com/remlapretep/104_0454.JPG FE107E Bi-amped with SP-3500 The 107's are now in my home office and I'm not parting with them ;^) They're just fine as is even without a sub for the .......
301: Tube DIY Asylum, Simply Great! Encore! Encore! (nt) (0.00)
Posted by PeterP on 2005-10-26, 20:48:00 (152.163.100.7)
. .......
302: High Efficiency Speaker Asylum, Re: Full / wide range suggestions wanted. (0.00)
Posted by PeterP on 2005-10-26, 06:21:57 (64.12.116.7)
You're quite right. I have run the Sansui SP-3500s as part of a bi-amped system with the Fostex speakers. That's very good and probably worth refining. However for this system, I'm looking to put toge .......
303: High Efficiency Speaker Asylum, Full / wide range suggestions wanted. (0.00)
Posted by PeterP on 2005-10-25, 21:08:09 (152.163.100.7)
OK. So I've made the progression from Sansui SP-3500s, to Godzilla's Pioneer 8", to a 6L dual ported Fostex FE107E. The Pioneer 8" gave me a taste of the "full range" single speaker and I must say tha .......
304: Tube DIY Asylum, Re: "great part" (0.00)
Posted by PeterP on 2005-10-23, 21:22:15 (64.12.116.7)
By "great part" I mean that it is extremely versatile. You can use it as an adjustable zener or comparator. Looking at the data sheet you will see "Stability Boundary Conditions". Basically the part c .......
305: Tube DIY Asylum, Re: Hate to seem so dumb (0.00)
Posted by PeterP on 2005-10-23, 17:30:56 (152.163.100.7)
The heater bias circuit gets its 330V directly off of the 250uF/450V cap. I also think that it's time we take this conversation off-line. If you have any more questions, feel free to contact me at: ph .......
306: Tube DIY Asylum, Re: Huh? (0.00)
Posted by PeterP on 2005-10-22, 18:17:59 (64.12.116.7)
Take a look at: http://eshare.hpphoto.com/en/home/view.asp?PhotoID=http://eshare.hpphoto.com/rs/7D90FB5D-DE06-4524-9EB5-F310E787EFD0/thumbnail&file=53CCA5AA47812D257A26785D1953F204&JobID=ed268702-6d58 .......
307: Tube DIY Asylum, Re: Touching wiper wire (0.00)
Posted by PeterP on 2005-10-22, 14:17:30 (205.188.116.7)
That's normal. Your body is acting as an antenna and the signal is being amplified. I did just go back to your schematic. One thing that stands out is the 6SL7. The plate voltage on the first stage I .......
308: Tube DIY Asylum, Re: 2A3 pp OT (0.00)
Posted by PeterP on 2005-10-22, 13:24:04 (205.188.116.7)
Right now I'm thinking of using two separate supplies. ~500V for the amplification and phase splitting. Thinking 76 directly coupled to 6J5 to an IT. I have two or three other ideas that I need to bre .......
309: Tube DIY Asylum, Re: Safety Ground (0.00)
Posted by PeterP on 2005-10-22, 12:58:05 (205.188.116.7)
In amps I keep the circuit and safety ground isolated by 10-100 ohms. This has to be a low enough value so that if a fault occurs, the input fuse will blow and not present a hazardous voltage to the c .......
310: Tube DIY Asylum, Re: Description of grounds (0.00)
Posted by PeterP on 2005-10-22, 08:25:17 (64.12.116.7)
"Your potentiometer case should be connected to the circut Common & not the Safety ground." If I wasn't clear, the volume pot (as a resistive element in the circuit) must be connected to the circuit c .......
311: Tube DIY Asylum, 2A3 pp OT (0.00)
Posted by PeterP on 2005-10-22, 07:41:28 (64.12.116.7)
I'm starting to think seriously about a 2A3 push-pull and wondering what output transformer to use. I was thinking about using a Hammond 6600 ohm with 8 ohm speakers on the 16 ohm tap for a primary im .......
312: Tube DIY Asylum, Re: Hum is driving me crazy!!!! (0.00)
Posted by PeterP on 2005-10-21, 14:56:00 (205.188.116.7)
It seems to me that you need to look into your grounding system. If the hum increases when you touch the shaft of the volume control, then it's not grounded like you think it is. Can you post or atlea .......
313: Tube DIY Asylum, Re: Hum is driving me crazy!!!! (0.00)
Posted by PeterP on 2005-10-21, 14:01:53 (205.188.116.7)
100K volume pots are usually fine. You've got noise getting from somewhere. You might try putting a resistor from the wiper to ground (right at the pot) with a value around 47K to see if that helps bu .......
314: Tube DIY Asylum, Re: Some answers and questions: Anybody get the HPGL working??? (0.00)
Posted by PeterP on 2005-10-21, 08:25:16 (152.163.100.7)
I also tried to use the standard HPGL/2 plotter in AutoCAD and could not get it to work. I finally set it up for a 7550 plotter and it works just fine. All I can suggest is to try different plotter dr .......
315: Tube DIY Asylum, Re: Hum is driving me crazy!!!! (0.00)
Posted by PeterP on 2005-10-21, 06:23:29 (152.163.100.7)
Just a thought. What is the value of the volume pot? Large value pots can present a high source resistance which can pickup noise (usually minimum noise at the two extreems, 0 and full volume, and wor .......
316: Tube DIY Asylum, Re: Front Panel Express Redux (0.00)
Posted by PeterP on 2005-10-21, 06:09:46 (152.163.100.7)
Some answers: For clearance holes go to: http://www.twocw.net/mit/NR/rdonlyres/Mechanical-Engineering/2-007Design-and-Manufacturing-ISpring2003/3F73E291-211B-4417-9AD3-667D3248B676/0/holesize.pdf#sear .......
317: Tube DIY Asylum, Re: TL431 Shunt Regulator question (0.00)
Posted by PeterP on 2005-10-21, 05:04:55 (152.163.100.7)
Corerosin is correct. The part in question is a 2SD1213. The data sheet can be found at: http://prelcoparts.com/datasheets/Prelco Sanyo Data Sheets/2SD1213.PDF From the data sheet it appears that the .......
318: Tube DIY Asylum, Re: TL431 Shunt Regulator question (0.00)
Posted by PeterP on 2005-10-20, 18:36:44 (205.188.116.7)
I've only seen this part in a plastic TO-92 package. I think it's available in a surface mount flat pack. Do you have a different package? BTW it is a great part, just pay attention to the design guid .......
319: Tube DIY Asylum, Re: 6L6 SE Oscillation (0.00)
Posted by PeterP on 2005-10-05, 08:52:07 (64.12.116.7)
True so true. Mono-blocks would be better still. However, if size or some other constraint is forcing the issue, shared screen and cathode circuits can be made to work and work well. Get it stable fir .......
320: Tube DIY Asylum, Re: 6L6 SE Oscillation (0.00)
Posted by PeterP on 2005-10-04, 18:14:45 (205.188.116.7)
http://gabevee.tripod.com/imageREC.JPG I assume that this is the circuit that you are using. If so I would suggest that you isolate the screen grids of the two channels by using any of the following: .......
321: Tube DIY Asylum, Thanks Doc. (0.00)
Posted by PeterP on 2005-10-02, 08:39:23 (172.155.78.225)
That was it. I just needed to setup an HPGL type plotter and plot to a file. Thanks again. Pete. .......
322: Tube DIY Asylum, Front Panel Express users. (0.00)
Posted by PeterP on 2005-10-01, 17:35:12 (172.155.78.225)
Is anyone familiar with FPE and AutoCAD? I'm trying to get my text and graphics for a front panel from AutoCAD into FPE. I'm feeling like "Roadkill on the information highway." It's probably something .......
323: Tube DIY Asylum, Fantastic work! (nt) (0.00)
Posted by PeterP on 2005-09-30, 20:06:41 (152.163.100.7)
. .......
324: Tube DIY Asylum, Re: Hissing/Static Noise in 300B Parafeed DRD amp (0.00)
Posted by PeterP on 2005-09-30, 12:36:36 (172.155.78.225)
Just a thought. If you turn off or unplug the amp, does the noise go away while the amp is running on the stored energy in the caps? Could be line noise getting into the amp. Just something to check. .......
325: High Efficiency Speaker Asylum, Dust cap replacement. (0.00)
Posted by PeterP on 2005-09-26, 06:54:26 (152.163.100.7)
I have two woofers with dented dust caps, way beyond using tape or a vacuum to fix. (Why do people do that?!) I've picked up replacements from partsexpress and would like to replace them. My question .......
326: Tube DIY Asylum, Re: Transitory problem in uControlled amp (0.00)
Posted by PeterP on 2005-09-25, 19:37:36 (152.163.100.7)
Just a thought. I see in your schematic that pins 11 and 31 are open. I have seen some strange behavior when all of the power pins are not used. Is that just an oversight in the schematic? If not try .......
327: Bottlehead Forum, Re: Cheap Bookshelf Ideas (0.00)
Posted by PeterP on 2005-09-23, 20:41:41 (64.12.116.7)
That's not a link. I just included the address because I wanted to make sure that there was a way to get to the picture if it didn't show up in the post. To use it you'll need to copy and paste it int .......
328: Bottlehead Forum, Re: Is that a Japanese Sonics speaker underneath? (0.00)
Posted by PeterP on 2005-09-22, 20:59:36 (205.188.116.7)
That's my Sansui SP-3500. Got them in Okinawa '74 and haven't been able to part with them since. Not the last word in detail or imaging, but one hell of a party speaker. 100dB/W/m makes them fairly tu .......
329: Bottlehead Forum, Re: Cheap Bookshelf Ideas (0.00)
Posted by PeterP on 2005-09-22, 19:06:07 (205.188.116.7)
You didn't mention if size was important. I just finished a nice small set of speakers for my office. They are Fostex FE107E speakers in a ported 6-liter cabinet (12.5"H x 6"W x 10.75"D). They won't d .......
330: High Efficiency Speaker Asylum, TS for Sansui W-114 (0.00)
Posted by PeterP on 2005-09-21, 06:05:24 (205.188.116.7)
Anyone have or know where to find the TS numbers for a Sansui W-114? It's the 14" woofer in the Sansui SP-3500. Thanks, Pete. .......
331: Tube DIY Asylum, Outstanding! (0.00)
Posted by PeterP on 2005-09-14, 13:12:33 (152.163.100.7)
While red is not my thing, that is one beautiful amp! I've always had a sweet spot for my Fisher which uses the same output tubes. Your workmanship is truly first class. My only comment: You're "a gra .......
332: High Efficiency Speaker Asylum, Re: cheap experiments (0.00)
Posted by PeterP on 2005-09-14, 05:07:05 (172.167.32.189)
That's exactly what I did. 1) full signal goes to preamp 2) split signal with Y-connector 3a) full-frequency signal ==> DIY 6EM7 pp tube amp ==> fullranger 3b) full-frequency signal ==> 12 Band EQ* w/ .......
333: High Efficiency Speaker Asylum, Bi/Tri Amp (0.00)
Posted by PeterP on 2005-09-13, 07:43:04 (152.163.100.7)
It would seem to me that the real benefit of bi/tri amping a system is the ability to tweak your speakers to your hearts content. Individual speaker efficiencies and band width are not nearly as impor .......
334: High Efficiency Speaker Asylum, What's next? (0.00)
Posted by PeterP on 2005-09-09, 06:01:06 (64.12.116.7)
Having finished my 6 liter FE107's and very pleased, I thinking what's next? My first thought is a 12 liter version using FX120's? (are they still available?) Any thoughts? Would this be a significant .......
335: Tube DIY Asylum, Re: Hmmm.... (0.00)
Posted by PeterP on 2005-09-09, 04:32:18 (172.159.92.206)
What value is the volume pot and grid-stopper? Is it quiet with the input shorted regardless of volume setting? .......
336: Tube DIY Asylum, Re: Aikido line stage noise oddness (0.00)
Posted by PeterP on 2005-09-07, 14:31:10 (152.163.100.7)
Just a thought. Is the volume control installed in the chassis and is the chassis grounded? Volume control pots can pick-up noise/buzz if the shaft isn't grounded. Good luck. Pete. .......
337: High Efficiency Speaker Asylum, OK, now I’m amazed! (0.00)
Posted by PeterP on 2005-09-07, 08:26:57 (152.163.100.7)
I just connected these speakers directly to my Sony Discman. No amp, just the Discman headphone output. With the volume set to 4 this is one fine office system. It will start to break up at about 8 on .......
338: High Efficiency Speaker Asylum, My new FE107E's (0.00)
Posted by PeterP on 2005-09-06, 18:27:57 (205.188.116.7)
Just got both FE107E speakers up and running. Thanks to all who offered guidance. They sound great! No tweeter on the top end and it seems just fine to me. I may add a super tweeter sometime in the fu .......
339: High Efficiency Speaker Asylum, Wishing you all the best. Good luck. (nt) (0.00)
Posted by PeterP on 2005-08-29, 06:27:17 (152.163.100.7)
.. .......
340: Digital Drive, CD Player suggestion wanted. (0.00)
Posted by PeterP on 2005-08-26, 16:04:44 (152.163.100.7)
OK, so I've had my dbx dx5 forever (well since '87) and now I'm putting together a dedicated headphone system. The system will be a DIY tube headphone amp and a CD player. Headphones are Grado SR125 a .......
341: Bottlehead Forum, Re: Finally, I did it - S.E.X. Amp ala Wardsweb (0.00)
Posted by PeterP on 2005-08-21, 20:44:58 (205.188.116.7)
That is one drop-dead gorgeous amp! Fantastic look! .......
342: Tube DIY Asylum, Resistor Power Ratings (0.00)
Posted by PeterP on 2005-08-17, 20:11:15 (64.12.116.7)
There have been some very good points brought up and you should consider them carefully. In addition I would just like to mention something about Power Ratings. If you don't have the data for your spe .......
343: Bottlehead Forum, You're not alone. (0.00)
Posted by PeterP on 2005-08-08, 10:16:00 (205.188.116.7)
I'm not a big Senn fan myself. I perfer the Grado sound. I just wish that they were more comfortable. Next time I'll be looking at Beyerdynamics. I want something that I can put on and forget that the .......
344: Bottlehead Forum, Re: Anyone knows where can I find a stereo pot for a Foreplay II??? (0.00)
Posted by PeterP on 2005-08-08, 07:17:30 (152.163.100.7)
Before you jump in and change anything please find out what the problem is. Using an ohm-meter trace the input to the pot, the input to ground, and the input to the tube grid. If all the resistances a .......
345: Bottlehead Forum, Re: My second scratch build: the Cavalli-Lovell Mk II headphone amp (0.00)
Posted by PeterP on 2005-08-08, 07:05:01 (152.163.100.7)
Very nice! I like the Bottlehead look. Just a few questions? What headphones are you using / tried? What are you using for power supply caps? Your work just keeps getting better. Enjoy. Pete. ::: TOPI .......
346: Bottlehead Forum, Re: Headphone jack into Foreplay (0.00)
Posted by PeterP on 2005-07-31, 19:44:23 (64.12.116.7)
FWIW I've used the line and headphone outputs from several diskman, sounds cards, etc. and have found for the most part it is best if you run the volume at about 70% from the headphone source. That se .......
347: Tube DIY Asylum, Re: What's the schemo? (nt) (0.00)
Posted by PeterP on 2005-07-08, 08:27:13 (152.163.100.7)
Give me some time and I'll get it posted. Basically it's a 6SL7 SRPP RC coupled to a 46. The 46 is cathode biased with a CCS on top (22mA). The output is from the low impedance output of the CCS to a .......
348: Tube DIY Asylum, New Project Pics. (0.00)
Posted by PeterP on 2005-07-08, 07:48:26 (64.12.116.7)
I've had this one in the works for over a year. It's a 46 headphone amp. Kids, work, and 1001 excuses however I finally got it to the point that I have pics of my "final" fit check of the top plate. M .......
349: High Efficiency Speaker Asylum, FE107E needs more bass. (0.00)
Posted by PeterP on 2005-07-07, 20:51:00 (64.12.116.7)
Just got the first of the pair up and running. For such small speakers (only 6 liter boxes) they do very well. I could live with these for most music but, true to the design, they run out of gas about .......
350: K&K Audio / Lundahl Transformers, Re: Amps in progress (0.00)
Posted by PeterP on 2005-06-23, 08:19:24 (64.12.116.7)
WOW! That really looks great. Although it's good to see someone who takes as long as I do to build an amp, you really put my so-called "craftsmanship" to shame. Don't forget to ground those inserts fo .......
351: Tube DIY Asylum, Re: I think you worry too much. (0.00)
Posted by PeterP on 2005-06-22, 12:37:11 (64.12.116.7)
Definitely, too many years of designing for mil-spec weapon systems has made me a little neurotic. Just looking to squeeze the best performance out of the parts I'm using. Thanks for the info. Pete. : .......
352: Bottlehead Forum, Take care, best wishes.......... (0.00)
Posted by PeterP on 2005-06-21, 20:17:31 (64.12.116.7)
and don't forget to post the x-rays. .......
353: Tube DIY Asylum, Hammond help. (0.00)
Posted by PeterP on 2005-06-21, 06:04:58 (205.188.116.7)
I just recently picked up a new pair of Hammond 1615 transformers. When I removed the end bells, I noticed two things that bothered be. 1. The insulating washers are just insulating flat washers NOT s .......
354: Tube DIY Asylum, Re: Purple Heart ST35 amp (0.00)
Posted by PeterP on 2005-06-14, 08:37:26 (64.12.116.7)
Man, drop out for almost 2 weeks and look what I almost missed. Very nice! The Dynaco sound is a great place to start and with those OT's it should sound very good. Since I haven't heard the DIYTUBE P .......
355: High Efficiency Speaker Asylum, An added 2¢ (0.00)
Posted by PeterP on 2005-06-02, 10:21:12 (64.12.116.7)
Just thought I’d toss this into the mix. You need to decide what’s important. Portability, comfort, and budget will greatly affect your decision. I’m a Grado person. Many people find the comfort of Gr .......
356: High Efficiency Speaker Asylum, Re: I need good headphones and there is no Headphone Fourm (0.00)
Posted by PeterP on 2005-06-02, 06:12:15 (64.12.116.7)
Go to Head-Fi. It's one of the best and most active sites dedicated to headphones and headphone users. Spend some time there and I'm sure you'll find more than you care to know. You'll find info and o .......
357: Tube DIY Asylum, Clipping. (0.00)
Posted by PeterP on 2005-05-13, 15:18:25 (205.188.116.13)
I'm thinking SETs here but it should apply to PP as well. In all of the amps that I've seen, there is more than enough gain between the VA and driver stage to clip the power output tube. The output po .......
358: Tube DIY Asylum, Re: Do these have the same hole spacing as UX5 types? (0.00)
Posted by PeterP on 2005-05-06, 15:12:57 (172.166.111.12)
I have the 4pin, 5pin, and the octal. All have the same size ceramic. The mounting holes are the same. I don't care for how close the rivets are to the chassis, they don't touch, however it's too clos .......
359: Tube DIY Asylum, Re: The Octal Solution? These Really Look Awesome! ! ! (0.00)
Posted by PeterP on 2005-05-05, 16:36:58 (152.163.100.7)
I've used them in breadboards so far. I really like how they hold up to soldering and unsoldering connections again and again. I'll be using them in a final design if I can ever stop playing with the .......
360: Tube DIY Asylum, Re: Sounds like 2 resistors have been misplaced (0.00)
Posted by PeterP on 2005-04-30, 20:11:54 (64.12.116.7)
From you previous post it seems as though R1 and R3 are swapped. "I did find some numbers on the resistors, R1- RN600 1500F Dale R2- RN600 1000F Dale R3- 1003F dale" 1500 = 150 ohms 1000 = 100 ohms 10 .......
361: DIY HiFi Forum, FWIW. (0.00)
Posted by PeterP on 2005-04-21, 18:45:41 (205.188.116.13)
In reality, the input capacitance is going to be less than 100pF but, when you take into account the source impedance, the resistance will be more than the 82K. In any case, the -3dB point (without th .......
362: DIY HiFi Forum, Re: Don't do it (0.00)
Posted by PeterP on 2005-04-21, 18:35:01 (205.188.116.13)
Did you also include the 100pF cap to bypass the 82K resistor? If not, and if you assume about 100pF of input capacitance, then the -3dB point will calculate to about 19.4KHz. The more I read about it .......
363: High Efficiency Speaker Asylum, Cabinet for 4" Fostex? (0.00)
Posted by PeterP on 2005-04-20, 22:09:34 (152.163.100.7)
My son wants to build a small set of speakers in shop class. I'm thinking Fostex FE103E or FE107E in a 4-6 liter cabinet. Any suggestions to get the most out of these 4" speakers in such a small box? .......
364: DIY HiFi Forum, BTW (0.00)
Posted by PeterP on 2005-04-17, 16:17:22 (152.163.100.7)
I'm very interested in the STC mod. When you made this mod, how did it affect the gain of the output stage? It sounds to me like you are running out of drive from the phase splitter. Pete. ::: TOPIC:: .......
365: DIY HiFi Forum, 25Vpp = 8.8Vrms (0.00)
Posted by PeterP on 2005-04-17, 16:11:34 (152.163.100.7)
Don't confuse peak-to-peak with peak. Remember that (for a sine wave) Vpp = 2xVp Vrms = Vp / sqrt(2) Wrms = (Vrms)^2 / load 25Vpp = 12.5Vp 12Vp = 8.8Vrms 8.8Vrms will give ~19Wrms into 4 ohms Remember .......
366: Vintage Asylum, Re: What happened to your college.... (0.00)
Posted by PeterP on 2005-04-07, 16:29:29 (172.150.172.17)
Started building mine in ’71 with a pair of UTAH AS-2 speakers. They now serve me well as office speakers with a Pioneer 8” and ratshack tweeter. In ’74 I got the rest of my system in Okinawa. A Pione .......
367: Vintage Asylum, Re: Sansui SP-35 tweeter replacement (0.00)
Posted by PeterP on 2005-04-06, 12:01:04 (205.188.116.132)
Bob, Thanks, you've described the woofer exactly. Thanks for the tips. I'll give them a try. Pete. .......
368: Vintage Asylum, Re: Sansui SP-35 Not a bad fullranger (0.00)
Posted by PeterP on 2005-04-05, 20:59:40 (152.163.100.7)
Bob, Since the tweeters were not correct I thought I'd see if anyone knows if Sansui W-117 is the correct woofer? 7.8 ohms 15W as marked. It does sound quite good when run as a fullranger. IMO it stil .......
369: Vintage Asylum, Re: Sansui SP-35 (0.00)
Posted by PeterP on 2005-04-05, 15:06:45 (172.132.219.117)
I did listen to them with the tweeter disconnected. Sounded pretty good but definately not fullrange. I'll try bypassing the crossover and run the woofer as a fullranger. Maybe, if it's needed, I'll a .......
370: Vintage Asylum, Sansui SP-35 (0.00)
Posted by PeterP on 2005-04-05, 13:00:39 (172.132.219.117)
Just picked up a pair of SP-35's. The boxes are in very good shape but the tweeters have been replaced with Pyle tweeters. I'll be hunting down replacements however, in the meantime is there a readily .......
371: High Efficiency Speaker Asylum, Looking for another cubic foot of fun. (0.00)
Posted by PeterP on 2005-04-02, 12:17:00 (205.188.116.132)
I'm looking to DIY a pair of speakers for a small 11"x12'x7' room. I would like the cabinet to about 1 cu. ft. I've done the Pioneer 8" and it's nice and polite especially at low volumes. However they .......
372: Tube DIY Asylum, Safety first. (0.00)
Posted by PeterP on 2005-03-31, 17:05:40 (64.12.116.7)
When you say... "I know virtually *nothing about safety with high voltage amps." I can't but wonder what level of experience you have. Keep in mind that even "low" voltage tube amps can be fatal. Just .......
373: Tube DIY Asylum, Re: Help needed on a Berman 76 preamp (bit long) (0.00)
Posted by PeterP on 2005-03-28, 18:22:34 (64.12.116.7)
Just two quick observations from the picture. 1. There is no bypass cap on the 76 cathode resistors? Did you have any when you did your breadboard? 2. Can't tell if the heater voltage is grounded, flo .......
374: Tube DIY Asylum, Have you looked at....... (0.00)
Posted by PeterP on 2005-03-02, 18:08:32 (172.142.52.29)
Plitron ( http://www.plitron.com/ ), has a PAT-22 chassis. 0.375 thick front panel with a 0.125 thick chassis that's 17W x 22D. It looks quite nice but, at $240 in the 1-4 piece price it's out of my b .......
375: High Efficiency Speaker Asylum, Re: Don't see a headphone forum so I'll ask here (0.00)
Posted by PeterP on 2005-02-28, 22:12:42 (172.142.52.29)
Try: http://www6.head-fi.org/forums/ You can find info on headhpones for just about any application and any price range. Good folks, LOTS of opinions. BTW So far I'm a Grado fan but I'm always looking .......
376: Tube DIY Asylum, Small connectors. (0.00)
Posted by PeterP on 2005-02-25, 15:13:40 (205.188.116.7)
I'm in the process of putting together a headphone amp with a seperate power supply. My goal is to make the amp as small as possible. I need two small connectors. 1. 300V and Return (dual mono) 4 cont .......
377: Tube DIY Asylum, Re: You are most likely right (0.00)
Posted by PeterP on 2005-02-16, 17:21:25 (205.188.116.7)
Adding a 100 ohm or 1K resistor between the gate of the current source and the tube plate can work wonders. Plus is makes for a convenient measurement of the current. I have also had success by simply .......
378: Tube DIY Asylum, SRPP or White Follower (0.00)
Posted by PeterP on 2005-01-16, 21:22:42 (172.147.110.214)
I've used SRPP's as drivers with reasonable results and I've read about White Followers used for OTL outputs for headphones (ala http://headwize.com/projects/showfile.php?file=bender_prj.htm). I would .......
379: Tube DIY Asylum, Re: Run Step-Down Power Transformer Backwards, For Step Up? (0.00)
Posted by PeterP on 2004-12-22, 05:49:49 (64.12.116.7)
Think of the transformer coils as having a Volts/Turn rating. That means that you should not have more than the voltage rating on any one coil regardless. It doesn’t matter if it is used as an input o .......
380: Tube DIY Asylum, Re: More Hammond 1628SE Testing (0.00)
Posted by PeterP on 2004-12-20, 04:28:41 (152.163.100.7)
Not exactly apples to apples is it? That's what sales pitches are all about. And....,the good sales pitches have some truth and (hopefully) no out-and-out lies. In any case, it provides some useful in .......
381: Tube DIY Asylum, Re: 845 Amp Schem - some Qs (0.00)
Posted by PeterP on 2004-12-19, 20:28:29 (205.188.116.7)
That's a "magic eye" tube used to display output level. I couldn't find it on Franks Tube Data site or my favorite site for magic eyes http://web.telia.com/~u87149908/eyes/ The 6E2 is the tube up fron .......
382: Tube DIY Asylum, More Hammond 1628SE Testing (0.00)
Posted by PeterP on 2004-12-19, 07:30:21 (64.12.116.7)
Just thought I'd share this site that has "tested" 7 transformers including the Hammond 1628SE. http://www.sacthailand.com/transformerTest1.html I haven't lived with any other OT than the Hammonds (16 .......
383: Tube DIY Asylum, Absolutely right. (0.00)
Posted by PeterP on 2004-12-11, 17:34:53 (64.12.116.7)
Sometimes cables, input impedance, etc. can suck all the life out of a passive preamp. If you're using a Foreplay and would like to try unity gain while keeping a low output impedance, then take a loo .......
384: Tube DIY Asylum, Re: Just The Info I Needed--You Guys Rock! (0.00)
Posted by PeterP on 2004-12-09, 12:43:40 (64.12.116.7)
On a day to day basis I'm listening to my Grado 125's (32ohms) through a pair of 115V:22V+22V via my 6EM7 pp amp. This gives me about 150 ohms to match a passive cross-feed circuit that I have. I did .......
385: Tube DIY Asylum, I'll second this one. (0.00)
Posted by PeterP on 2004-12-09, 08:56:38 (64.12.116.7)
I listen to the potted 10VA toroids every day and think that they are great. Huge over kill but they look good. http://dkc3.digikey.com/PDF/T043/1310.pdf The IXCP is an exceptional device for the mone .......
386: Bottlehead Forum, Re: dunno if this helps (0.00)
Posted by PeterP on 2004-11-21, 08:58:45 (64.12.116.7)
Thanks Doc. I appreciate the thought and at least it wasn't an Ongaku. For less than $20 it's playing as good as new. I think I'll leave the cracked chassis to serve as a reminder of how luck I was. P .......
387: Bottlehead Forum, Big Blue Amp takes a fall. (0.00)
Posted by PeterP on 2004-11-21, 06:09:42 (205.188.116.7)
This past Thursday was Black Thursday for my group in Lucent. 23, including me, in my department alone were let go. I packed my office amp and put it on the top of a hand cart. For those of you who re .......
388: Tube DIY Asylum, Re: PP 46 amp (0.00)
Posted by PeterP on 2004-10-29, 15:50:58 (205.188.116.7)
Is the buzz still there? Did you measure the voltage across the 100 ohm resistor (AC and DC)? Is there an AC voltage between the source chassis and the amp chassis? I'm very interested in this amp. Pl .......
389: Tube DIY Asylum, Forgot to mention. (0.00)
Posted by PeterP on 2004-10-28, 18:33:07 (172.149.224.163)
While you're trying to find your grounding problem, you should disconnect your source. If you have a volume control on the amp you can get away with turning the volume to zero. If not, you should make .......
390: Tube DIY Asylum, Re: PP 46 amp (0.00)
Posted by PeterP on 2004-10-28, 15:49:40 (205.188.116.7)
You've got a problem with the power or instrumentation. Do you have a schematic to share showing the power supply? Double check your power isolation, hot, neutral, and ground. If you ohm out the two i .......
391: Tube DIY Asylum, Re: PP 46 amp (0.00)
Posted by PeterP on 2004-10-27, 17:23:34 (64.12.116.7)
I've been looking at doing a PP 46 for quite some time now. I did breadboard a headphone/preamp and that will be my next project. But if you haven't tied the circuit ground to chassis ground, you shou .......
392: Tube DIY Asylum, Our kind of opamps. (0.00)
Posted by PeterP on 2004-09-30, 15:20:07 (64.12.116.9)
Found this today and just had to share it. http://www.national.com/rap/vacuumtubes.html Enjoy. Pete. .......
393: Tube DIY Asylum, Thanks John (nt) (0.00)
Posted by PeterP on 2004-09-28, 20:02:36 (152.163.100.7)
. .......
394: Tube DIY Asylum, Re: Hale Fellow Cathode Feedbacker, Well Met (0.00)
Posted by PeterP on 2004-09-28, 19:54:23 (152.163.100.7)
This breadboard goes back to June ’01. Has it really been that long?! If you go to http://db.audioasylum.com/cgi/m.mpl?forum=bottlehead&n=27104&highlight=PeterP&r=&session= you can see how it all star .......
395: Tube DIY Asylum, Re: Parallel 6SL7 sections. (0.00)
Posted by PeterP on 2004-09-28, 16:50:56 (152.163.100.7)
Any of your suggestions come in an octal sized socket? I've already punched the chassis. I could always use one of Doc's sockets and maybe try a 6N1P. The output stage is EL34/KT88/Ei90 etc. (triode o .......
396: Tube DIY Asylum, Re: Let's Make A Deal... (0.00)
Posted by PeterP on 2004-09-28, 16:41:57 (152.163.100.7)
Nothing special here. I used an IXCP 10M45S. http://rocky.digikey.com/WebLib/IXYS/Web Data/IXCP10M45S.pdf I think that they work great for driver and output circuits. I used it for the first time in t .......
397: Tube DIY Asylum, Parallel 6SL7 sections. (0.00)
Posted by PeterP on 2004-09-27, 18:50:01 (205.188.116.9)
Just playing with my KT88 SE and thought that I'd settled on a CCS loaded 6SL7 as the amp/driver. Just for kicks I doubled the current, adjusted the cathode resistor and paralleled the sections. The r .......
398: Tube DIY Asylum, Re: 5965, 7119, 2C51 & 6DJ8 good-Use a choke as top cathode resistor (0.00)
Posted by PeterP on 2004-09-26, 12:05:15 (152.163.100.6)
I have used a Hammond 156C (150H 3700ohms) with a 6SL7 and thought that it worked really well. Just had to play with location and orintataion to keep hum pick-up out of the circuit. This can be a nice .......
399: Tube DIY Asylum, Re: Jim... (0.00)
Posted by PeterP on 2004-09-26, 11:58:54 (152.163.100.6)
I never really gave it much thought except for higher voltages or seperate tubes like the 76. Interesting you find that it loses it's sparkle in a short period of time. You refer to gnd referenced sup .......
400: Tube DIY Asylum, SRPP suggestions. (0.00)
Posted by PeterP on 2004-09-25, 16:36:23 (152.163.100.6)
OK, I'll admit it. When it comes to SRPP's I like 'em. But so far I can say that I like 76 and 6SL7 as SRPP's with a B+ of about 300V. I can't seem to find a 6SN7 SRPP that I like. Now I'm looking for .......
401: DIY HiFi Forum, Ella with an IT? (0.00)
Posted by PeterP on 2004-09-04, 18:28:41 (64.12.116.9)
Has anyone tried a triode modded Ella with an interstage transformer? Seem like a fairly easy mod, although finding a home for 2 IT's may be a bit hard. Seems to me that it would change the op point o .......
402: Tube DIY Asylum, Re: push pull spud (0.00)
Posted by PeterP on 2004-09-02, 05:26:54 (192.11.226.120)
Here's mine. A 6EM7 PP, dirt simple with lots of room for improvement, but I listen to it about 6hrs each day and I like it. http://www.geocities.com/remlapretep/php_audio.htm Good luck, Pete. ::: TOP .......
403: Bottlehead Forum, Re: Any other "Non-Snubber" ways to get rid of Foreplay buzz? (0.00)
Posted by PeterP on 2004-08-29, 19:15:18 (64.12.116.9)
Have you tried to isolate the transformer? That worked for me. Just unscrew it and isolate it from the chassis with a piece of paper. If that works for you then you can check the archives for ways to .......
404: K&K Audio / Lundahl Transformers, Sansui (0.00)
Posted by PeterP on 2004-08-29, 18:11:25 (205.188.116.9)
I still have my pair of Sansui SP-3500 (1974). I must admit that when it comes to everything except "crank-it-up and party" I like my Pioneer full-rangers (http://www.melhuish.org/audio/DIYBX16.html) .......
405: Tube DIY Asylum, Re: Where to get a nice looking biasing meter? (0.00)
Posted by PeterP on 2004-07-19, 19:37:00 (64.12.117.11)
Have you tried? http://www.meterdistributor.com/ They carry a large selection of panel meters that may be what you're looking for. I haven't used them, however looks interesting. .......
406: Tube DIY Asylum, Or how about?? (0.00)
Posted by PeterP on 2004-05-19, 18:50:38 (64.12.116.9)
What about using a thermistor and a relay. I've done this in several commercial power supplies and it works just fine. When you use just a thermistor, one of the major drawbacks is short term power ou .......
407: Tube DIY Asylum, Now that is sweet!!!! (0.00)
Posted by PeterP on 2004-05-17, 19:43:18 (205.188.116.9)
Fantastic job. Pete. .......
408: Tube DIY Asylum, Re: Best cheap CD Player mentioned in a thread a while back? (0.00)
Posted by PeterP on 2004-05-13, 15:19:50 (64.12.116.9)
I think that you are referring to the Toshiba 3960. Do a search on all forums for 3960 and you'll find lots of info. Pete. .......
409: K&K Audio / Lundahl Transformers, Re: LL1660 / 10mA with 46 driver. (0.00)
Posted by PeterP on 2004-05-13, 13:13:55 (152.163.252.99)
I was thinking of using it reversed as a 2:1 stepdown. Perhaps that is not a good choise? In any case I'll be playing with the LL1660/10mA first. Thanks for the input. Pete. .......
410: K&K Audio / Lundahl Transformers, Re: LL1660 / 10mA with 46 driver. (0.00)
Posted by PeterP on 2004-05-11, 16:37:26 (172.208.191.95)
So then a LL1677/80mA with a 300b or 2A3 might be a better choice? I'll have to give that some carefull consideration. I intend to try the 76-46 and probably 6EM7 with the LL1660/10mA just to see. I d .......
411: K&K Audio / Lundahl Transformers, LL1660 / 10mA with 46 driver. (0.00)
Posted by PeterP on 2004-05-10, 19:23:27 (205.188.116.9)
I’m kicking around an idea for my next amp. It’s a high power SET 76-46(triode)-IT-211 and my question is can I use a LL1660 / 10mA (which I have) configured as 2 : 2.25 and get good performance when .......
412: DIY HiFi Forum, Re: Joplin as an Headphone amp. (0.00)
Posted by PeterP on 2004-05-10, 17:44:32 (64.12.116.9)
At work I have been using my Grado's with a 115V : 44V (10VA) transformer (Power mains toroid). At these light loads the transformer is closer to 115V : 50V. I've also added a crossfeed circuit. I fou .......
413: Tube DIY Asylum, Looking for more cap advise. (0.00)
Posted by PeterP on 2004-05-01, 17:07:25 (64.12.116.9)
I’m looking for a cap to use in a parafeed application. I’ll need a value of about 2-3uF and greater than 300V. It will be working into a 10K ohm load (for a preamp output). I’m building this into a v .......
414: Tube DIY Asylum, Congrats! So what's next? (nt) (0.00)
Posted by PeterP on 2004-04-30, 19:57:54 (152.163.252.5)
nt .......
415: Tube DIY Asylum, Cathode bypass caps. (0.00)
Posted by PeterP on 2004-04-24, 19:32:51 (152.163.252.5)
I know, I know, find a way to not have to use a cathode bypass but.... When used as cathode resistor bypass, has anyone compared Elna Cerafine Series ARA to Black Gate Premium FK/K? Or is there someth .......
416: Tube DIY Asylum, Looking for a mu (10 (0.00)
Posted by PeterP on 2004-04-24, 14:37:41 (205.188.114.36)
I've got a breadboard of a 46 headphone amp up and running. I had a 6SN7 on the front end. I removed it and found that for most music from CD or tuner I have more than enough gain to drive my Grados. .......
417: SET Asylum, How about a 46? (0.00)
Posted by PeterP on 2004-04-22, 21:17:36 (205.188.116.9)
I haven't been in the Asylum for a while but couldn't pass up your post. I've been using my 6EM7 PP amp at work for both speakers and headphones and I wanted to see what all the hype was about for DHT .......
418: Tube DIY Asylum, 6EM7 gets my vote. (0.00)
Posted by PeterP on 2004-01-13, 20:59:22 (152.163.252.5)
If you can live with 1.5W, the 6EM7 is hard to beat for good cheap fun. Just keep the power section to the recommended op point of ~150V and 50mA and the sound is great. I would think that being only .......
419: High Efficiency Speaker Asylum, 6EM7 push pull amp (0.00)
Posted by PeterP on 2004-01-13, 20:22:12 (152.163.252.5)
The 6EM7 amp that I'm using is the one that is in Valve. Check out: http://www.valvediy.com/6em7pppg1.html or my site: http://www.geocities.com/remlapretep/php_audio.htm .......
420: High Efficiency Speaker Asylum, What he said. (0.00)
Posted by PeterP on 2004-01-13, 20:07:17 (152.163.252.5)
njjohn's correct. It's that simple. My 6EM7 has taken up residence at work. (Maybe now I'll finish my KT88 SE) It's on and playing 8-10 hours/day. While everyone likes the sound, I've had comments fro .......
421: Tube DIY Asylum, Re: Williamson amp - and another great site. (0.00)
Posted by PeterP on 2004-01-08, 19:36:05 (64.12.96.9)
I forgot to add: http://www.triodeel.com/hipower.html more reading for you. Pete. .......
422: Tube DIY Asylum, Re: Williamson amp (0.00)
Posted by PeterP on 2004-01-08, 19:22:57 (64.12.96.9)
You should take a good look at: http://www.xs4all.nl/~ideas/amps/ It explains the Williamson in quite a bit of detail. Enjoy, Pete. .......
423: Tube DIY Asylum, Re: 8W 6AS7 CF - Check my work? (0.00)
Posted by PeterP on 2003-12-30, 20:33:11 (205.188.208.9)
You'll need more B+ to get to 8W. You won't get more peak voltage out of the cathode follower than B+. So you'll be http://www.audiodesignguide.com/my/se.html My first amp started out as this one and .......
424: Tube DIY Asylum, Re: 8W 6AS7 CF - Check my work? (0.00)
Posted by PeterP on 2003-12-30, 18:47:04 (205.188.208.9)
I've been playing with a direct coupled 6SN7 lately and I did find that the choke loaded driver sounded better with more voltage and current. So far I've come around to close to the standard point. I' .......
425: Tube DIY Asylum, Re: 6sn7 lacks highs...Any suggestions? (0.00)
Posted by PeterP on 2003-12-30, 18:03:45 (205.188.208.9)
Keeping in mind that I need to keep this to a single tube (preferribly an octal), what would you suggest? I'm open to other dual triodes, pentodes etc. I do plan to try a version of Pete Millett's des .......
426: Tube DIY Asylum, Re: How much gain? (0.00)
Posted by PeterP on 2003-12-29, 20:12:30 (152.163.252.5)
Short answer: gain of both stages ~140 I found tonight that there was a HF oscillation that I got rid of by reducing the Feed Back. I inserted 62ohms in series with the winding and paralleled the comb .......
427: Tube DIY Asylum, Gentlemen, Gentlemen (0.00)
Posted by PeterP on 2003-12-29, 19:48:45 (152.163.252.5)
please, the purpose of my post was to get opinions of specific op points. Not to start a pis###g contest. I appreciate you're passion and conviction but let me be more specific. 1. Keeping to the publ .......
428: Tube DIY Asylum, Re: Another question (0.00)
Posted by PeterP on 2003-12-28, 17:40:49 (205.188.208.9)
I haven't measured anything on this amp yet. All I know is it sounds very good and the DC measurements are what I expected. I need to clean up the breadboard and take it into work where I can put a sc .......
429: Tube DIY Asylum, #!@% I think this works. (0.00)
Posted by PeterP on 2003-12-28, 10:35:47 (152.163.252.5)
Try going to: http://www.geocities.com/remlapretep/audio.html .......
430: Tube DIY Asylum, Another try. (0.00)
Posted by PeterP on 2003-12-28, 10:11:33 (152.163.252.5)
OK, let's try this again. http://www.geocities.com/remlapretep/images/SE_UL.pdf http://www.geocities.com/remlapretep/images/Img_0338.jpg Sooner or later I'm going to stop being: "Just road kill on the .......
431: Tube DIY Asylum, Another SE UL (0.00)
Posted by PeterP on 2003-12-28, 09:07:20 (205.188.208.9)
Here's yet another KT88 SE UL design. I thought that I'd squeezed out all the performance that I could, but after seeing Pete Millett's post, I realized that I have not listened to it for about a year .......
432: Tube DIY Asylum, Try this site. (0.00)
Posted by PeterP on 2003-12-13, 20:24:00 (64.12.96.9)
Tom's right. Frank's site is an excellent resource. This one seems to be working: http://www.mif.pg.gda.pl/homepages/frank/index.html Pete. .......
433: Tube DIY Asylum, A Bose Christmas??????? (0.00)
Posted by PeterP on 2003-12-06, 17:03:07 (64.12.96.9)
After 2 Hrs. of shoveling snow, I came back to see this sight. Now you know why my system is down stairs and I am happily banished to the basement. ;^) http://www.geocities.com/remlapretep/images/Bose .......
434: Tube DIY Asylum, Wooden Chassis - Safety (0.00)
Posted by PeterP on 2003-11-20, 17:34:16 (64.12.96.9)
cheap-Jack makes a good point and I failed to emphasize it. With a wooden chassis or any chassis that is not conductive, please make sure that all exposed metal is grounded. Not just the obvious, tran .......
435: Tube DIY Asylum, Re: Wood "deck" for tube amp project (0.00)
Posted by PeterP on 2003-11-19, 18:19:54 (205.188.208.9)
My amp at: http://www.geocities.com/remlapretep/php_audio.htm uses MDF. I mounted the tube sockets on top to get a little more space between the tube and the chassis. Seems to work just fine. I use th .......
436: Tube DIY Asylum, Re: the dog ate my post? (0.00)
Posted by PeterP on 2003-11-07, 14:53:24 (205.188.208.9)
James' site was the one that caught my eye in the first place. It looks like ~1W SE seems to be the best way to go however, for me, I'd only be able to use it as a headphone amp ('till I get different .......
437: Tube DIY Asylum, 46 Amp Suggestions (0.00)
Posted by PeterP on 2003-11-06, 17:57:56 (152.163.252.5)
I'm starting to think about my next project and would like to consider using a 46 dual grid tube. So I'd like some suggestions. What's the best 46 amp you've heard? The contenders so far are: 1. Nosta .......
438: Tube DIY Asylum, Re: A not very magic box (0.00)
Posted by PeterP on 2003-10-30, 19:50:23 (152.163.252.5)
If it's built as drawn, the 1K balance pot is way too high. It will drop too much voltage and there will be very little for the LM317. You could just jumper each end of the pot to the wiper with 10 - .......
439: Tube DIY Asylum, TL431 Data Sheet. (0.00)
Posted by PeterP on 2003-10-28, 15:24:34 (64.12.96.9)
For a detailed data sheet check out: http://www.onsemi.com/pub/Collateral/TL431-D.PDF Hope that helps. Pete. .......
440: Tube DIY Asylum, Re: PSE EL84 problem/question (0.00)
Posted by PeterP on 2003-10-19, 12:02:34 (152.163.252.5)
Silly question. It sounds like you may actually have positive feedback. Did you try reversing the phase of the output of your OT? Just a thought. Pete. .......
441: Vintage Asylum, Fisher KM-60 (0.00)
Posted by PeterP on 2003-09-15, 18:41:42 (152.163.252.5)
I just re-connected my Pioneer SX-828 to my main system so that I could use the tuner. The system consists of: Preamp--Marantz 3300 (while I rework my Foreplay) CDP--dbx DX5 Tuner--Fisher KM-60 Tuner- .......
442: Tube DIY Asylum, Have you seen........? (0.00)
Posted by PeterP on 2003-07-30, 18:26:54 (64.12.96.10)
I've never heard it, however, from what I've read the Direct Reactance Drive (Electra-Print Audio) is supposed to be quite good. http://www.electra-print.com/drd300b.html Well worth a look. Pete. ::: .......
443: High Efficiency Speaker Asylum, Thanks for the info. (0.00)
Posted by PeterP on 2003-07-29, 21:03:01 (205.188.208.9)
Thank you, in my brief search I found several sites which refer to planars as ribbons. Sure would be nice if we all spoke the same language. ;^) .......
444: High Efficiency Speaker Asylum, Please educate me. (0.00)
Posted by PeterP on 2003-07-29, 19:57:56 (205.188.208.9)
What's the difference between a ribbon and a planar? Sound and construction. Or could you point me in the right direction? Thanks. .......
445: High Efficiency Speaker Asylum, First real taste of ribbons. (0.00)
Posted by PeterP on 2003-07-29, 19:33:02 (205.188.208.9)
I picked up a pair of Infinity EMIT k tweeters and I must say I really like what I hear. I now have two questions...first does anyone know where I can find the spec for the 902-3082N (used in the Kapp .......
446: Tube DIY Asylum, Re: MH4 - 171A - IT - 300b finally done. (0.00)
Posted by PeterP on 2003-06-25, 19:16:02 (205.188.208.9)
Wow! That is nice. Please tell me it sounds as good as it looks. I'm sure a lot work went into that layout. Looks great. Pete. .......
447: Tube DIY Asylum, Looking to crack the 100W barrier?? (0.00)
Posted by PeterP on 2003-06-25, 19:10:30 (205.188.208.9)
I guess we won't be seeing you over at the High Efficiency Speaker Asylum! Now if that was only 100W SE....but that would put you well into KV land ;^) You're going to have to start building amps on w .......
448: Tube DIY Asylum, 'cause the data sheet says so and it sounds good. (0.00)
Posted by PeterP on 2003-06-25, 16:26:49 (205.188.208.9)
That's the short answer. Now for the long winded version. If you look at the data sheet for the 6EM7 you will see that the recommended op-point for the power section is 150V at 50mA. From what I've re .......
449: Tube DIY Asylum, Re: anybody have the PS schematic for the PP 6em7? (0.00)
Posted by PeterP on 2003-06-24, 19:16:41 (64.12.96.10)
I've been too lazy to put a schematic together. It's pretty well covered in the Valve article but I'll try to get a real schematic this week. Thanks for the nudge. Pete. .......
450: Tube DIY Asylum, C4S is still going strong. (0.00)
Posted by PeterP on 2003-06-24, 19:10:45 (64.12.96.10)
I'm still using the Bottlehead C4S set to 3mA. I've tried changing the current but I always come back to the 1.5mA per section. I did try the IXCP10M45S constant current and found that with my system .......
451: Tube DIY Asylum, Very nice! (0.00)
Posted by PeterP on 2003-06-23, 20:49:59 (152.163.195.187)
and a great job under the hood. Congrats. Pete. .......
452: Tube DIY Asylum, Yet another 6EM7 (0.00)
Posted by PeterP on 2003-06-23, 20:08:24 (152.163.252.5)
If you can live with ~2W go with Gary's 6EM7 SE and put the money into quality magnetics and caps. If you need more power, clocking in at just under $500 you can do a push-pull. http://www.valvediy.co .......
453: Tube DIY Asylum, Re: What is KT100 tube like ? (0.00)
Posted by PeterP on 2003-06-09, 20:22:58 (152.163.252.5)
I haven't heard it yet, it is supposed to be similar to a KT88 but rated at 50W and 600V. Check out: http://www.diyhifisupply.com/tube_supplies/valve_art_tubes.html There's not much info out there abo .......
454: Tube DIY Asylum, Trust your ears. (0.00)
Posted by PeterP on 2003-06-04, 17:45:13 (205.188.208.9)
"PS is shunt regulated with a ccs and VR tubes. CCS loads on the 12SN7 too. The 5Y3 and a 5R4GY both sound good, and better than Mullard GZ34, or 6087, or 5V4GA." All that isolation from input to amp .......
455: Tube DIY Asylum, Re: Hear, hear! (0.00)
Posted by PeterP on 2003-06-01, 07:39:41 (152.163.252.5)
I too only use a DVM (or an old Simpson) and my ears. I think that everyone is getting wrapped-up in their interpretation of "good engineering practice". What does it really mean? In my opinion it is .......
456: Tube DIY Asylum, Re: no good engineering practice says....... (0.00)
Posted by PeterP on 2003-05-31, 08:32:16 (64.12.96.10)
Yes, but do you have a circular slide rule? Wish I still had mine. As for good engineering practice, once you have all the transfer functions for all the pieces involved and not just the amp, then you .......
457: Tube DIY Asylum, By the way. (0.00)
Posted by PeterP on 2003-05-30, 17:46:30 (152.163.252.5)
I have found that the above formula matches the graph pretty well but, Resistor in ohms = 10^((3.2565-LOG(Current in mA))/0.8988) matches the parts that I have. I'm not sure if what I have is typical .......
458: Tube DIY Asylum, What works for me. (0.00)
Posted by PeterP on 2003-05-30, 14:43:50 (205.188.208.9)
If you look at the table for 300 ohms you'll see that the set current is not very accurately set (7 - 15mA). As best as I can get from the graph the equation for the resistor value is: Resistor in ohm .......
459: Tube DIY Asylum, Re: More CCS fun. Have you tried IXCP10M45S? (0.00)
Posted by PeterP on 2003-05-28, 20:24:16 (152.163.252.5)
I picked-up a few of these awhile back and just got around to playing with them. First up was the driver in my KT88 SE-UL. After quite a bit of changing things I had settled on a 6SL7 SRPP which I tho .......
460: Tube DIY Asylum, Re: 6C45-211 amp is born! -=pictures=- (0.00)
Posted by PeterP on 2003-05-28, 19:50:01 (152.163.252.5)
Very, very nice! I'm looking forward to the final schematic and an update about the sound. What are you using for OT's? Pete. .......
461: Bottlehead Forum, Re: Cope's beasts (0.00)
Posted by PeterP on 2003-05-21, 15:33:38 (152.163.252.5)
Sorry I missed your 8's. I still can't stop thinking about Cope's speakers, simply fantastic. I was very happy to hear my amp on those Cornwalls. Now I know I need to upgrade my speakers. If I only ha .......
462: Tube DIY Asylum, 6EM7 FYI (0.00)
Posted by PeterP on 2003-05-20, 18:07:12 (152.163.252.5)
For all of you who aren't tired of hearing me rave about the 6EM7.... Antique Electronic Supply http://www.tubesandmore.com/ is selling them at $2.00 each again ('till July 15). I don't know what bran .......
463: Bottlehead Forum, Great time! (0.00)
Posted by PeterP on 2003-05-18, 18:36:32 (205.188.208.9)
Great food, people and fantastic equipment. I don't think that I've seen so many great amps, tt, speakers, pre and phono amps in one place. A special thanks to Steve and Mrs. C for hosting the NE Bot .......
464: Dynaco-Doctor Forum, And the Asylum Continues to Grow.... (0.00)
Posted by PeterP on 2003-05-14, 21:57:23 (64.12.96.10)
Looking foward to another great addition. Maybe now I'll get off my butt and restore my MKIII's. Welcome. Pete. .......
465: Tube DIY Asylum, Power Supply (0.00)
Posted by PeterP on 2003-05-14, 17:09:20 (205.188.208.9)
The power supply consists of 3 basic voltages. The transformer is a Hammond 370HX The 275AC is rectified with a 5U4 to a LC for about 175V B+ It also is rectified with a 6X5 to a CRC for about 320V Th .......
466: Tube DIY Asylum, ????????????? (0.00)
Posted by PeterP on 2003-05-01, 14:32:39 (205.188.208.9)
Please try that again. Pete. .......
467: Tube DIY Asylum, Re: Include grid-ground resister or not? (0.00)
Posted by PeterP on 2003-04-30, 17:15:17 (64.12.96.10)
Just my take on it. Although I don't always practice what I preach ;^) and including the resistor is certainly not required. I like to include a resistor right at the tube. I do this for two reasons. .......
468: Tube DIY Asylum, Re: which of these power tubes (0.00)
Posted by PeterP on 2003-04-29, 17:47:29 (205.188.208.9)
The JJ KT88 SE-UL gets my vote and one of my "fun" favorites. I run it with no overall NFB, self biased with cathode feedback and a 6SL7 SRPP driver. I like it and it gives you plenty of oportunity to .......
469: DIY HiFi Forum, Ella gets raves. (0.00)
Posted by PeterP on 2003-04-25, 15:36:35 (64.12.96.10)
Well, I delivered my "Ella ala Pete" last week. After about a two week "in home audition" the guy that I built it for came to me and said: "First, it is quiet! Much quieter than my old Sansui (solid s .......
470: Tube DIY Asylum, VA(in)=VA(out) (0.00)
Posted by PeterP on 2003-04-19, 17:43:12 (152.163.188.5)
Short of other perameters, you can think of it as the input voltage (rms) times the input current (rms) = the output voltage (rms) times the output current (rms). What have you got in mind? Pete. ::: .......
471: Tube DIY Asylum, Re: KT88 drivers. (0.00)
Posted by PeterP on 2003-04-19, 05:56:15 (205.188.208.9)
I did try a 76 SRPP into a LL1660 IT. I like it a lot however it only has a gain of about 10. Remember since I'm using a cathode feedback winding on my KT88 I need about 66Vrms of drive to push the ou .......
472: Tube DIY Asylum, KT88 drivers. (0.00)
Posted by PeterP on 2003-04-18, 10:06:37 (192.11.223.116)
So I'm back to playing with my KT88 SE. With cathode feedback the KT88 has a gain of about 3. I need a clean 70Vrms to drive that. I've tried a 6SL7 SRPP which works pretty well. It has the right gain .......
473: DIY HiFi Forum, That's ground. (0.00)
Posted by PeterP on 2003-04-15, 18:07:50 (205.188.208.104)
I thought that as long as I was going to use tip jacks for the bias test points I'd add one for ground at each pair. It works out great, I set the bias for each tube using the ground and then zero the .......
474: DIY HiFi Forum, Ella Pics (0.00)
Posted by PeterP on 2003-04-14, 19:36:36 (152.163.188.5)
Finally posted a few pictures at: http://www.geocities.com/remlapretep/Ella_Page.html I've been running it almost non-stop for about a week now. Break-in did improve things just a bit. It did go throu .......
475: Tube DIY Asylum, What works for me. (0.00)
Posted by PeterP on 2003-04-10, 16:54:02 (205.188.208.104)
This is not meant to be a full blown curcuit analysis package. It does a pretty fair job and is quite usefull. When splitting off, go to the "insert" menu and insert a current tap. Set the current for .......
476: Tube DIY Asylum, I'll second that. (0.00)
Posted by PeterP on 2003-04-07, 17:41:49 (152.163.188.5)
If you can live with about a 1W the 6EM7 makes a great SE amp. Although the power triode can handle 330V, if you keep to the "standard" op point of 150V @50mA, I think that you'll find the sound much .......
477: DIY HiFi Forum, Re: Which tubes are you using in your Ella? (0.00)
Posted by PeterP on 2003-04-07, 14:03:34 (152.163.188.5)
IMHO the Valve Art KT88's are quite good. That's what I'm running and they seem to be a nice compliment to the other "stock" tubes. I have tried: Best midrange.........JJ KT88's Best bass............. .......
478: DIY HiFi Forum, Re: Ella Bias instability at low freq? (0.00)
Posted by PeterP on 2003-04-07, 13:09:35 (152.163.188.5)
Just a couple of thoughts. 1. Is this measurement using a scope or a meter. I know my meter starts to give funny readings above 1KHz and I don't trust the readings beyond that. 2. I would expect to se .......
479: Bottlehead Forum, Re: Bottlehead Meeting, MD, DC, DE, PA, NJ - great meeting (0.00)
Posted by PeterP on 2003-04-06, 15:57:01 (64.12.96.10)
Ray, Just wanted to say thank you for hosting the meeting. It was good to put faces with names I've seen here. Not to mention all the equipment that everyone brought. Definitely the most (and some of .......
480: Tube DIY Asylum, Re: Best Way to Repair Burned PCB Traces? (0.00)
Posted by PeterP on 2003-04-04, 17:03:58 (205.188.208.104)
I have found that the best way for me to repair a board is to: 1. Clean it thoroughly with alcohol. 2. Using insulated, solid wire, re-route the trace and, if possible, solder it into a feed-through h .......
481: DIY HiFi Forum, Ella sings! (very long) (0.00)
Posted by PeterP on 2003-03-30, 19:17:03 (152.163.188.5)
OK, so my "one week to go" took a month and a half. You've just got to hate it when life gets in the way of having fun ;^) But it was well worth the wait. I made some minor changes along the way. 1. A .......
482: Tube DIY Asylum, Re: ISO: high quality 6DN7 datasheets (0.00)
Posted by PeterP on 2003-03-19, 09:59:41 (192.11.226.116)
Have you tried: http://frank.pocnet.net/sheets/093/6/6DN7.pdf I've found this to be a fairly good resource. Just a thought. Pete. .......
483: Tube DIY Asylum, Me too....... (0.00)
Posted by PeterP on 2003-03-07, 14:51:36 (205.188.208.104)
I've used JJ 100+100/500V in the power supply and feel that they work just fine for "bulk" capacitance. You may be able to find a better price, but thetubestore has them. http://www.tubestore.com/jjel .......
484: Tube DIY Asylum, Re: Nina Preamp - Another Photo (0.00)
Posted by PeterP on 2003-02-18, 16:30:10 (152.163.188.5)
Looking good! What did this replace? How does it compare? Any pics under the hood? Pete. .......
485: Tube DIY Asylum, Re: New phono preamp (0.00)
Posted by PeterP on 2003-02-18, 16:21:08 (152.163.188.5)
Very nice. Really like the finish on that top plate. Pete. .......
486: Bottlehead Forum, Don't deburr that hole! (0.00)
Posted by PeterP on 2003-02-18, 16:10:52 (152.163.188.5)
Just got around to playing catch up and noticed your post. Follow the PEM guidelines for hole sizes and don't deburr the hole. I've found that it's best to drill from one side and install from the oth .......
487: High Efficiency Speaker Asylum, OK. I'm lost. (0.00)
Posted by PeterP on 2003-02-09, 18:23:02 (205.188.208.104)
Over on the Fostex site I came across the FF225K. http://www.fostex.co.jp/int/pages/sets/prodset.htm It looks interesting. It'll need help at the top end and probably could benefit from a sub. The rec .......
488: DIY HiFi Forum, In about a week. (0.00)
Posted by PeterP on 2003-02-06, 15:23:18 (152.163.188.5)
Of course when I say a week, it will probably end up being 2 or 3 weeks. In any case I'll make sure to post pics. I guess I now need to pay special attention to the inside ;^) Pete. .......
489: DIY HiFi Forum, Re: A question about grounding probe for bias readings (0.00)
Posted by PeterP on 2003-02-05, 19:36:07 (152.163.188.5)
I'm in the process of building a modified Ella. Most of the mods are just cosmetic however, that's why I used real tip-jacks and added a ground on each side. Just in case the image link doesn't work i .......
490: Bottlehead Forum, Re: Old school decoder. You left out......... (0.00)
Posted by PeterP on 2003-01-31, 17:10:46 (205.188.196.56)
You left out the tolerance........Get Some Now Get.....Gold.....- 5% Some....Silver...- 10% Now.....No color.- 20% Damn I've been doing this stuff way too long. But...I've learned to embrace my demen .......
491: K&K Audio / Lundahl Transformers, Re: best driver for LL1660/10 in SE amp (0.00)
Posted by PeterP on 2003-01-23, 18:42:38 (152.163.188.5)
FWIW The best I've been able to do is using a 76 SRPP. See: http://www.audioasylum.com/forums/KandK/messages/287.html I've tried 6SL7, 6SN7 & KT66 (the 66 really wasn't too bad even at only 8mA). Mayb .......
492: K&K Audio / Lundahl Transformers, That's a keeper. (0.00)
Posted by PeterP on 2003-01-19, 06:59:36 (205.188.208.104)
Kevin, Thanks for the input. You're exactly right about the configuration. Right now I've been leaning toward the 2A3's for the driver stage. But I'll have to take a look at the 10Y's. Again thanks. P .......
493: K&K Audio / Lundahl Transformers, Re: 1660/10ma for pp -pp. Now you've got my attention. (0.00)
Posted by PeterP on 2003-01-18, 17:21:26 (205.188.208.104)
I've been slowly planning a 211 push-pull and I'm sure it will be another year before I really start it. So far the leading design will use an input transformer to phase split. A 76 pp IT to an approp .......
494: DIY HiFi Forum, Ella just got here. (0.00)
Posted by PeterP on 2003-01-18, 13:44:19 (205.188.208.104)
Just opened my Ella Kit. I must say that overall I'm impressed. The overall quality is quite good. It's stock with KT88's and a power supply choke. I plan on building this as "Ella ala Pete". I'm buil .......
495: Tube DIY Asylum, Re: homebrew poor man's Ankoru (0.00)
Posted by PeterP on 2002-12-14, 11:59:38 (152.163.188.5)
Very, very nice! What does it weigh-in at? Maybe now I'll get off my butt and start that 211/845 that I've been planning for more than a year. Any pictures of under the hood? Absolutely great work. Pe .......
496: Tube DIY Asylum, Thank you Seth. (0.00)
Posted by PeterP on 2002-12-06, 15:56:27 (152.163.188.5)
I'd all but given up. I hadn't seen the one on Lynn's site. I still haven't been able to chat with anyone who has actually heard one but, like I said, I'm just gathering information right now. I still .......
497: Bottlehead Forum, Re: My new pride & joy! (tube headphone amp) (0.00)
Posted by PeterP on 2002-12-03, 18:59:43 (205.188.208.104)
Very nice. I like the clean look. I take it that you have opted to use two separate volume controls. Do you find that you pretty much set the volume and don't touch it during a listening session? I'm .......
498: Tube DIY Asylum, 205D (0.00)
Posted by PeterP on 2002-12-03, 16:43:36 (205.188.208.104)
There are other projects ahead of it but just started looking at the 205D. Looks good but was wondering what it sounds like. PP or SE. Anyone using this tube? What circuits? Maybe even as a driver? (A .......
499: Tube DIY Asylum, Re: 6em7 operating conditions (long) (0.00)
Posted by PeterP on 2002-12-01, 18:05:21 (205.188.208.104)
Sounds like you are running very close to the same op points that I'm using. (but you're pushing it just a little) Check out: http://www.geocities.com/remlapretep/php_audio.htm With this tube I've fou .......
500: Vintage Asylum, 3500's and stands. (0.00)
Posted by PeterP on 2002-11-29, 17:49:47 (152.163.188.5)
I find that I too like the 3500's when raised 8-12" off the floor. In my room there can be quite a bit of bass boom when they are directly on the floor. Pete. .......
Found total of 500 records, Query: , Author: PeterP in All Forums, Time: 1 sec.