|
Search of All Forums Enter your search criteria. Click here for tips on using our search |
For Sale Ads |
1: Tubes Asylum, RE: testing 6082 tubes (0.00)
Posted by Gary Kaufman on 2010-11-23, 10:22:54 (130.189.10.64)
Or use an outboard bench supply for the filament. - Gary .......
2: Tubes Asylum, RE: testing 6082 tubes (0.00)
Posted by Gary Kaufman on 2010-11-21, 10:25:28 (75.67.252.151)
Should have the same settings as a 6080 except for the 26.5v filament. Do you have a known good 6080 or 6AS7 you could test for comparison (with 6.3v filament obviously)? Does the filament measure cor .......
3: Tubes Asylum, RE: Avoid Russian ebay tube seller xryn (0.00)
Posted by Gary Kaufman on 2010-11-10, 09:46:20 (130.189.10.64)
The seller has 1557 feedbacks, 100% positive. I'm with Victor on this one. I worked with 6N1P's a few years ago. They are quite prone to oscillation. Google "6N1P Oscillation" and you'll see that you' .......
4: Tubes Asylum, RE: 5Z3 relabeled as #83?? (0.00)
Posted by Gary Kaufman on 2010-09-28, 04:40:07 (75.67.252.151)
Most certainly a 5Z3. Forget using it in a Hickok tester. National was notorious for re-labeling tubes, I have seen 6414's labeled as 12AT7's, Bendix 6106's labeled 5AR4's, 1U6's labeled as 1L6's etc. .......
5: Tube DIY Asylum, RE: How do you tell the difference between Novar and Noval when you order sockets? (0.00)
Posted by Gary Kaufman on 2010-09-26, 13:34:34 (75.67.252.151)
Well, just to add to your confusion, the EL519 is a MAGNoval, not a Novar As pointed out the Noval is the standard minature 9 pin socket, 12AX7 etc. Novar is the large 9 pin socket, 9 pin compactron t .......
6: Tube DIY Asylum, RE: tube electronic x-over (0.00)
Posted by Gary Kaufman on 2010-04-01, 12:32:46 (130.189.10.64)
Steve Bench's design is quite nice - I had 100 PC boards made up back in 2001, and finally sold out the last of them a few weeks ago (after 9 years). I'd consider another run of the PC boards if there .......
7: Tube DIY Asylum, RE: Tube Tester Advice (0.00)
Posted by Gary Kaufman on 2010-03-29, 13:06:22 (75.67.252.151)
Jim's right, $150 just isn't a reasonable budget for anything but an emissions tester. My favorite would be a TV7 - which would do what you're looking for, but a D/U in reasonable shape will set you b .......
8: Tubes Asylum, RE: That's so sad... (0.00)
Posted by Gary Kaufman on 2010-03-11, 19:14:59 (75.67.252.151)
Eli - To me, re-branding military surplus tubes as Amperex or placing a Gold Lion branding on a Russian tube is less than honest. It's especially sad when folks are surprised to see a TungSol 5881 tha .......
9: Tubes Asylum, That's so sad... (0.00)
Posted by Gary Kaufman on 2010-03-11, 14:23:40 (130.189.10.64)
New Sensor purchased many original tube names including TungSol and can now label whatever they want as a "TungSol". There is no comparison between the original TungSol 5881's you're holding and the c .......
10: Tube DIY Asylum, RE: Motorboating on 1935 radio I rebuilt (0.00)
Posted by Gary Kaufman on 2010-03-10, 10:52:04 (130.189.10.64)
This schematic from the web is pretty good, but I can try and get you a better copy tonight if you can't make it out. Look at R5/6/8/10 and make sure you didn't accidently replace any of the mica pf c .......
11: Tube DIY Asylum, RE: Motorboating on 1935 radio I rebuilt (0.00)
Posted by Gary Kaufman on 2010-03-10, 07:32:25 (130.189.10.64)
John - Go thru the resistors and look for ones that have drifted up - often a grid leak in the audio section. You can also trouble shoot by paralleling a resistor of approximately the correct value ac .......
12: Tubes Asylum, RE: Tall 12AT7: anyone familiar? (0.00)
Posted by Gary Kaufman on 2010-02-21, 20:41:49 (75.67.252.151)
Jim - You're correct, they are rebranded 6414's (which are a computer rated medium u type, fairly similar to a 12AV7). I ran into a few hundred 6414's so have a bit of experience with them! As a rule, .......
13: Vintage Asylum, RE: Trouble shooting Eico HF-81 (0.00)
Posted by Gary Kaufman on 2010-01-08, 19:21:07 (75.67.252.151)
As Mark has pointed out, the power transformer is probably just fine. If the 350 ohm resistor is overheating, something downstream is drawing too much current. I'd bet strongly on the filter caps, but .......
14: Vintage Asylum, RE: You might try going to an active crossover (0.00)
Posted by Gary Kaufman on 2009-12-30, 08:13:15 (130.189.10.63)
Don't sell the AC-22 short - just swap the input and output op-amps for LM4562 and you'll be pleasantly surprised. On the original AC-22 the op-amps of interest are the 8 pin ones (leave the filter se .......
15: High Efficiency Speaker Asylum, RE: So no-one likes Altec amps (0.00)
Posted by Gary Kaufman on 2009-12-23, 10:17:26 (130.189.10.63)
I'd suspect the limited response is because the overlap of folks with both Altec speakers and Altec tube amps are probably pretty small. I've run A-5's with 128B's - it's a nice combination, but I run .......
16: Vintage Asylum, Dynaco Vintage Tube Gear Manuals (0.00)
Posted by Gary Kaufman on 2009-12-17, 11:19:51 (130.189.10.63)
Several years ago I scanned all of the vintage Dynaco tube manuals into PDF files and sold them on CDRom. I've intended to post them on the web for free downloading - but until recently just didn't f .......
17: Vintage Asylum, RE: Seeking Radio Craftsmen C400 schematic... (0.00)
Posted by Gary Kaufman on 2009-11-14, 17:54:22 (75.67.252.151)
Very nice amplifier - it is surprising how good the little Radio Craftsmen 6V6 amplifiers can sound. I can help you out with the schematic, PM me. Be warned that Radio-Craftsmen made changes in the C4 .......
18: Tubes Asylum, RE: WE396a source (0.00)
Posted by Gary Kaufman on 2009-11-07, 06:50:43 (75.67.252.151)
They're actually fairly common, as WE tubes go. 2C51 is the same tube. If you're willing to modify the filament supply, also identical electrically is the WE407A (20/40v filament) - and dirt cheap. Ea .......
19: Vinyl Asylum, 0 for 1 (0.00)
Posted by Gary Kaufman on 2009-09-01, 09:53:57 (130.189.10.63)
I picked up a Technics SL1200MK2 off of Ebay, which was in nice cosmetic condition - but with a known problem with the drive system. Figured worse case I could swap parts with another cosmetically cha .......
20: Tubes Asylum, RE: 6V6 equivalent (0.00)
Posted by Gary Kaufman on 2009-08-19, 18:40:48 (75.67.252.151)
Somehow I'd be suspicious that this is a date code (eg 48th week of 1975). The "real" 7548 is a 9 pin hexode. - Gary .......
21: Tubes Asylum, RE: 485V Regulated Power Supply - Schematic Please (0.00)
Posted by Gary Kaufman on 2009-06-04, 06:26:47 (130.189.10.63)
True enough - I was thinking of the 1000v and 2000v Kepco's in the same series. http://www.the-planet.org .......
22: Tubes Asylum, RE: 485V Regulated Power Supply - Schematic Please (0.00)
Posted by Gary Kaufman on 2009-06-03, 18:27:41 (75.67.252.151)
The 8068 has pretty amazing specs, 35W, 3.5KV @ 100ma ratings. A 6BG6GA won't come close. I vaguely recall Eric Barbour commenting that Kepco had approached Svetlana about tooling up for a run of 8068 .......
23: Tubes Asylum, RE: 485V Regulated Power Supply - Schematic Please (0.00)
Posted by Gary Kaufman on 2009-06-03, 06:29:42 (130.189.10.63)
Actually you'd be far from crazy to build a regulator with tubes. Kepco, Lambda and others made some very rugged regulated tube supplies that were far more reliable than the generations of solid state .......
24: OTL Asylum, RE: Use Caution (0.00)
Posted by Gary Kaufman on 2009-03-22, 17:40:07 (75.67.252.151)
Nothing was ever sent, or received as you are aware. If anyone would like to see the "less polite" response Anthony sent directly to me I'd be happy to share it. Caveat Emptor http://www.the-planet. .......
25: OTL Asylum, Use Caution (0.00)
Posted by Gary Kaufman on 2009-03-22, 06:33:11 (75.67.252.151)
It's possible that there are more than one Anthony Naso's interested in audio, but I'd urge anyone planning business to use caution. I traded some of the Steve Bench crossover boards with an Anthony N .......
26: Tubes Asylum, RE: 300B's on TV7 (0.00)
Posted by Gary Kaufman on 2009-03-19, 06:11:31 (130.189.10.63)
I'd second the recommendation to either get the service manual or send the unit off to Dan Nelson. Tube testers rarely have a single problem, and if one voltage is off, do you really trust the others? .......
27: Tubes Asylum, 300B's on TV7 (0.00)
Posted by Gary Kaufman on 2009-03-18, 17:10:06 (75.67.252.151)
Somethings fishy - With a 5v filament setting the expected range (no load) is 5.15 - 5.68vac The TV7D/U I just pulled off the floor measured 5.53vac I hope you aren't testing 300B's at 6.3 or 7v fila .......
28: Tubes Asylum, RE: WTF is going on with my TV7U & 300B Tubes (0.00)
Posted by Gary Kaufman on 2009-03-18, 06:53:54 (130.189.10.63)
Remember that you have a 40+ year old test instrument that was probably last calibrated in the 1970's. I haven't seen too many TV7's that worked well as found. Time to download the TV7 service manual .......
29: Tube DIY Asylum, RE: are ST70 this sensitive? (0.00)
Posted by Gary Kaufman on 2009-02-12, 19:42:40 (75.67.252.151)
Your advise was great, a very nice summary. The ST70 (and Mark III) ran filter caps pretty close to their ratings - too close. Heathkit was better in this regard and often stacked two caps for a high .......
30: Tube DIY Asylum, RE: blown gz34 st70 (0.00)
Posted by Gary Kaufman on 2009-02-09, 14:24:40 (75.67.252.151)
The ST70 is a worse case design for the rectifier and filter caps. Most 5Y3's won't survive, I wouldn't chance it. A 5U4GB is just fine short term if you don't have a 5AR4. Also running the ST70 with .......
31: Tubes Asylum, RE: 7189 Tubes - Help! (0.00)
Posted by Gary Kaufman on 2009-01-29, 17:05:01 (12.187.211.54)
Yup, normal for 6BQ5 and 7189 on TV7's http://www.the-planet.org .......
32: Tubes Asylum, RE: Did Mullard ever make a 5670/ 2C51 type? (0.00)
Posted by Gary Kaufman on 2009-01-13, 14:17:09 (130.189.10.63)
Actually the 6386 is the variable mu version. The 6385 is a Bendix version, but is not variable mu. http://www.the-planet.org .......
33: Tubes Asylum, RE: United 966 - Any Info? (0.00)
Posted by Gary Kaufman on 2008-12-08, 13:44:06 (75.68.59.194)
It's an 866 http://www.the-planet.org .......
34: Tubes Asylum, RE: Getterless 826? (0.00)
Posted by Gary Kaufman on 2008-11-26, 11:48:40 (130.189.10.63)
Most 826's were not gettered. A significant percentage of 826's will have 1/2 of the filament broken. If you power up the filaments these will glow a duller color and have no emission. While I've had .......
35: Tubes Asylum, RE: What are WE 415A's a sub for/equivalent to? (EF91/92/95/408a?) (0.00)
Posted by Gary Kaufman on 2008-11-25, 07:07:33 (130.189.10.63)
The WE 415A is essentially identical to the WE 409A and similar to a 6AS6. WE408A's use a 20v filament, so a 415A won't substitute - 408A's are essentially a 6AK5 with a 20v filament where a 403B is t .......
36: Tube DIY Asylum, 'cause it works fine. (0.00)
Posted by Gary Kaufman on 2008-09-16, 12:25:09 (130.189.10.61)
Ok, not a popular opinion, but some switchers work just fine. Forget the cheezy PC supplies. Look for Lambda, Kepco, Vicor etc. Some of the better DC-DC converters are great for tube filaments. You're .......
37: Tube DIY Asylum, RE: LM317 problem, anyone experience this? (0.00)
Posted by Gary Kaufman on 2008-09-03, 12:15:03 (130.189.10.61)
Add protection diodes and your problems should go away. See page 9 of the data sheet at: http://www.national.com/ds/LM/LM117.pdf - Gary .......
38: Tube DIY Asylum, RE: settings to test a 8975 or 8950 (0.00)
Posted by Gary Kaufman on 2008-08-18, 08:57:11 (75.68.59.194)
8950 should test as a 6LQ6 with a 12v filament. The 8975 is essentially a 12 pin 6KG6 (which is a Magnoval). You should be able to adapt those setting, but I don't know the exact pinout of the 8975 :: .......
39: General Asylum, RE: Who is offering $89 air fare between WA and MA? (0.00)
Posted by Gary Kaufman on 2008-08-11, 17:33:01 (75.68.59.194)
Dan - You obviously haven't lifted a Mc240 anytime recently - 56 lbs (without any packing). The mono Mc40 is over 30 lbs. ref: http://www.roger-russell.com/amplif1.htm#mc240 - Gary .......
40: Tubes Asylum, RE: Source for 6414s? (0.00)
Posted by Gary Kaufman on 2007-12-11, 06:44:53 (130.189.15.61)
Send me an email if you can't locate 6414's. I have a few thousand used 6414's and could easily help you out. - Gary .......
41: Tubes Asylum, RE: Bendix 6106 Question (0.00)
Posted by Gary Kaufman on 2007-10-30, 13:29:04 (130.189.15.61)
PIV is not an issue as long as it is greater (which it is in the 6106). PIV is not the voltage drop, but rather the peak inverse voltage. I'm not certain, but I recall the voltage drop with a TE-22/61 .......
42: Tubes Asylum, RE: 6BG6A? (0.00)
Posted by Gary Kaufman on 2007-10-17, 17:41:20 (75.68.59.194)
See your email. The tube is a 6BQ7A, in a pinch a 6DJ8 will probably work fine. - Gary .......
43: Tube DIY Asylum, RE: finished gary kaufmans 6s4 amp a few questions (0.00)
Posted by Gary Kaufman on 2007-10-15, 18:58:26 (75.68.59.194)
Hope you enjoy it - it's a cute little amp. Frankly at the low power levels involved I don't think you'll get enough output at 30hz to make a difference. I personally haven't built this amp with any o .......
44: Tubes Asylum, RE: Difference btw Heathkit W3M & W3AM (0.00)
Posted by Gary Kaufman on 2007-10-15, 18:49:38 (75.68.59.194)
Actually the differences are extremely small - Just a few changes to the feedback loops, coupling caps to the phase inverter and an additional snubber on the output. The basic circuit, transformers, p .......
45: Tubes Asylum, Because the HF81 sounds better! (0.00)
Posted by Gary Kaufman on 2007-10-12, 18:20:20 (75.68.59.194)
I've owned all three - sold off every ST40 and ST70 I've owned. Still have a couple of HF81's. The ST40's are clunky looking, and nothing spectacular sonically. The HF81's are rather sweet sounding. O .......
46: Tube DIY Asylum, RE: Express PCB (0.00)
Posted by Gary Kaufman on 2007-10-03, 18:45:28 (75.68.59.194)
Paul - You have to set up a custom item. I have patterns for 7 and 9 pin minature, compactron and octal sockets. Email me privately and I can set you up with them. - Gary .......
47: Tube DIY Asylum, RE: 71A schematic... (0.00)
Posted by Gary Kaufman on 2007-10-03, 17:07:45 (75.68.59.194)
Vinnie and others - This was a simple "on paper only" conversion of JC's 3.5 Micro to use 71A's. I've never built it myself, but am thrilled that Vinnie has (and that it worked out nicely). I'll have .......
48: Tubes Asylum, RE: B&K 747B calibration clarification (0.00)
Posted by Gary Kaufman on 2007-09-25, 12:34:29 (130.189.15.61)
Tell me about it - tubes are easy, it's those darn SMT parts I can't see, much less solder. I was mostly pointing out that 5 watts in a 100M resistor wouldn't be necessary in any imaginable audio situ .......
49: Tubes Asylum, RE: B&K 747B calibration clarification (0.00)
Posted by Gary Kaufman on 2007-09-25, 11:36:57 (130.189.15.61)
Even 1/2 watt is overkill. Given P=V^2/R, a 100M resistor would dissipate under 1/2 watt up to around 7,000v (which I'm sure is way over the voltage rating of any resistor). 5W would get you up around .......
50: MagneQuest/Peerless Forum, RE: FS-100 or FS-100PF? (0.00)
Posted by Gary Kaufman on 2007-09-19, 09:05:38 (130.189.15.61)
I'm just a series feed sort of guy. The conventional FS-100 is such a nice transformer that I decided to use it again. "Better is the enemy of good" .......
51: MagneQuest/Peerless Forum, RE: So what do you think of the FS -100's? (0.00)
Posted by Gary Kaufman on 2007-09-19, 03:59:46 (75.68.59.194)
Probably the best answer is that I just ordered a second pair :) - Gary .......
52: MagneQuest/Peerless Forum, RE: I just popped in ... (0.00)
Posted by Gary Kaufman on 2007-09-18, 18:10:45 (75.68.59.194)
I'm surprised the 6C45 is up to driving a GM70 properly. I run a BCP-15 choke loaded 6C45 (B+ 250v) --> 211 (825vdc/70ma) and it works nicely. (As this is a MQ forum I should also point out that outpu .......
53: Tube DIY Asylum, RE: Trouble with active crossover (0.00)
Posted by Gary Kaufman on 2007-07-05, 06:32:58 (130.189.15.61)
I'd bet on a noisy resistor. If you decide to rebuild the channel fire me a private email and I'll send you out another PCB. Much easier than desoldering! - Gary .......
54: Tube DIY Asylum, Re: Tek curve tracer (0.00)
Posted by Gary Kaufman on 2006-02-15, 07:34:19 (130.189.41.3)
I believe the 575 version with higher voltage was marked "mod 122". There's a bit about it in Alan Douglas' book on tube testers and test equipment. I don't believe it is a simple change - as I recal .......
55: Tube DIY Asylum, Re: ST-70 Buzz - chokes? (0.00)
Posted by Gary Kaufman on 2006-02-03, 10:32:48 (130.189.41.3)
I agree with Charles - and would add - if the choke is buzzin' do look at the filter cap (sometimes the first section has dried out, and the power supply is acting more like a choke input). If it isn' .......
56: Tube DIY Asylum, Re: Any Recommendations for capacitance Meter ? (0.00)
Posted by Gary Kaufman on 2006-01-27, 09:06:01 (216.195.222.6)
Depends what you want to do... Repair equipment with lots of electrolytic caps -> ESR Meter Reform Vintage Electrolytic caps -> Eico 950B or Heathkit IT-11 (which will need to be rebuilt itself...) Me .......
57: Tube DIY Asylum, Re: review: Electro Harmonix 6973 (0.00)
Posted by Gary Kaufman on 2005-05-20, 10:47:52 (130.189.41.169)
Joel - You might want to try some 6CZ5 or 6EM5's in the amp. Both are fairly similar types to 6973 and NOS are still reasonable in cost. No personal experience with any of these - but before you shelv .......
58: Vintage Asylum, Re: Source for Heathkit AA-32 Schematic???? (0.00)
Posted by Gary Kaufman on 2005-05-18, 14:48:09 (69.163.32.114)
Nope, linky is dead. - Gary .......
59: Tubes Asylum, See your email (nt) (0.00)
Posted by Gary Kaufman on 2005-05-15, 07:25:46 (69.163.32.114)
NT .......
60: Tube DIY Asylum, Re: Eico 950B cap tester (0.00)
Posted by Gary Kaufman on 2005-05-11, 17:22:06 (69.163.32.114)
If the 4 and 8 uf caps are good (and the polarity correct), I'd suspect the 6X5. There isn't much more to the power supply. .......
61: Vintage Asylum, W3M (0.00)
Posted by Gary Kaufman on 2005-05-11, 15:19:23 (69.163.32.114)
You have a Heathkit W3M, the output transformer is an Acrosound TO-300. The orange wire is the 8 ohm tap, which is how your amplifier is probably wired. The unusued orange tap is probably actually bro .......
62: Vintage Asylum, Re: can you tell if it was smoked? (0.00)
Posted by Gary Kaufman on 2005-05-10, 21:43:22 (69.163.32.114)
Dave - Which output transformer is on the amplifier. With 5881's you probably have a W2 or W3. The W1/2/3 all use the same power supply, and are all very similar. I can get you started with the correc .......
63: Tube DIY Asylum, Re: Ditto on 46's as drivers (0.00)
Posted by Gary Kaufman on 2005-05-08, 08:03:07 (69.163.32.114)
Andrew - Care to post your circuit, I'd be very interested! - Gary .......
64: Tubes Asylum, Thanks Steve - (0.00)
Posted by Gary Kaufman on 2005-05-08, 07:59:06 (69.163.32.114)
For a very well put reply. As you describe, testing GM won't tell you poop about how well matched a pair of tubes will be in a real amplifier. As one example I can show you lots of pairs of 6L6GC's or .......
65: Tube DIY Asylum, Shhhhh.... (0.00)
Posted by Gary Kaufman on 2005-05-06, 18:08:23 (69.163.32.114)
46's are very sweet, don't tell anyone. Gordon Rankin's Bugle 45 adapts easily to 46's and sounds fantastic. .......
66: Tubes Asylum, Nah... (0.00)
Posted by Gary Kaufman on 2005-05-05, 18:18:18 (69.163.32.114)
Save the paper clips to pry it back out of the Loktal socket :_) Where's Vinnie when you need some clip leads! .......
67: Tubes Asylum, Re: testing 5u4's on TV-7 (0.00)
Posted by Gary Kaufman on 2005-05-05, 14:57:16 (69.163.32.114)
Well, unless you break off pins, the 7 pin socket is too small :) Seriously, it's the octal socket - but the TV7 does a poor job testing 5U4's. The B+ is only 150v. A 5U4 will rarely test bad on a TV7 .......
68: Vintage Asylum, Re: Transformer / Heathkit W-5M Question ... (0.00)
Posted by Gary Kaufman on 2005-05-05, 12:14:16 (69.163.32.114)
As Kyle points out, the leaking goo isn't that uncommon. Bad transformers however are very common on the W5 series - both power and outputs. I'm almost surprised when I get a W5 with both transformers .......
69: Tube DIY Asylum, OPT's (0.00)
Posted by Gary Kaufman on 2005-05-05, 06:50:10 (69.163.32.114)
I've not built Ralph Power's 6B4G, but I've owned or repaired all of these at some point. IMHO the Eico ST70 and Sansui 1000A have the nicest iron of the units you've listed. If the Eico ST70 wasn't s .......
70: MagneQuest/Peerless Forum, Re: Dynaco A-440 Transformer - Tertiary Windings (0.00)
Posted by Gary Kaufman on 2005-04-26, 08:30:44 (130.189.41.169)
I don't have the schematic drawn up, but would be happy to - I can describe it briefly... The main circuit is based on the design on PAE's site at: http://www.paeng-design.com/ The driver is a 6C45pi .......
71: Tube DIY Asylum, Re: Triode-connected 6146's? (0.00)
Posted by Gary Kaufman on 2005-04-25, 21:54:56 (69.163.32.114)
No personal experience, but I've heard that the screen rating is to be taken seriously - and is the problem with triode or UL modes in the 6146. Acrosound did publish a TO-350 circuit using a pair of .......
72: MagneQuest/Peerless Forum, Re: 2A3 schematics (0.00)
Posted by Gary Kaufman on 2005-04-25, 07:57:38 (69.163.32.114)
To echo what Mike suggested - I believe the Wellborne design is in his early catalogs - although some resistor values were omitted. Gordon Rankin has published the superb "Bugle 45" design which adapt .......
73: MagneQuest/Peerless Forum, Re: Dynaco A-440 Transformer - Tertiary Windings (0.00)
Posted by Gary Kaufman on 2005-04-25, 07:38:43 (69.163.32.114)
Nice link - thanks. I'm not sure I'd try 800v on the plate with most modern EL34's however :) Finding well matched sextets of Mullards would be a good challenge. I have lots of vintage EL34's and woul .......
74: MagneQuest/Peerless Forum, Re: Dynaco A-440 Transformer - Tertiary Windings (0.00)
Posted by Gary Kaufman on 2005-04-25, 07:32:21 (69.163.32.114)
Very neat - I had wondered about the "jump" to A-470. If you ever decide to build up some MQ-460's let me know! I've never seen an Acro TO-350 either (except on paper) - although I have one of the mat .......
75: MagneQuest/Peerless Forum, Dynaco A-440 Transformer - Tertiary Windings (0.00)
Posted by Gary Kaufman on 2005-04-24, 06:07:12 (69.163.32.114)
I ran into a single Dynaco A-440 transformer - a massive brute with tertiary windings for cathode or screen feedback. Their ads list it as being for PP Parallel EL34's for up to 200watts. Has anyone s .......
76: Tube DIY Asylum, Re: Update on the buzzing power tranny (0.00)
Posted by Gary Kaufman on 2005-04-21, 20:57:29 (69.163.32.114)
I wasn't sure of the temp required to soften tar - good info. I've un-potted several wax filled transformer cases at 225-250 degrees F with good results. Not that I take the potential toxicity of PCB' .......
77: Tube DIY Asylum, Re: Update on the buzzing power tranny (0.00)
Posted by Gary Kaufman on 2005-04-21, 19:08:48 (69.163.32.114)
Well, you've got nothin' to loose. As a last resort - I'd put it in an oven and slowly raise the temp to around 225 degrees - enough to hopefully soften the potting material if it's pitch/tar. I'd let .......
78: Tubes Asylum, Re: don't laugh! Any such thing as "good" 6GH8's? (0.00)
Posted by Gary Kaufman on 2005-04-21, 09:46:28 (130.189.41.169)
Mark - Email me privately and remind me to get you a pile. They are common as dirt. I can get you a tasting assortment. .......
79: Tube DIY Asylum, Re: PCBs for Ronan Regulators (0.00)
Posted by Gary Kaufman on 2005-03-26, 18:36:38 (69.163.45.49)
John Levreault had boards. I've sent you his email privately. - Gary .......
80: Tube DIY Asylum, No joke... (0.00)
Posted by Gary Kaufman on 2005-03-10, 16:34:55 (69.163.45.49)
I purchased a large number of TV7D/U's at auction. I paid a significant sum, but will end up with some very nice testers. .......
81: Tube DIY Asylum, Too wild... nt (0.00)
Posted by Gary Kaufman on 2005-03-09, 11:22:26 (130.189.41.169)
nt. .......
82: Tube DIY Asylum, Re: Works fine.... (0.00)
Posted by Gary Kaufman on 2005-03-09, 11:21:17 (130.189.41.169)
I'm not sure the voltage drop is all that critical. You might consider looking at the test equipment forum at www.antiqueradios.com which is frequented by Alan Douglas and others. Chris Haedt was also .......
83: Tube DIY Asylum, Works fine.... (0.00)
Posted by Gary Kaufman on 2005-03-09, 09:34:28 (130.189.41.169)
Turns out that in a TV7 solid state replacements for the 83 work well. This is per Alan Douglas' book, personal experience and other forums. This is less true in other Hickok testers btw. Also the 5Y3 .......
84: Tubes Asylum, tv7 au tube tester (0.00)
Posted by Gary Kaufman on 2005-02-23, 11:55:33 (69.163.45.49)
Any of the TV7's are great testers - the only significant differences are the addition of ferrite beads to later versions to decrease oscillation problems, and the additional "F" 60,000 umhos scale on .......
85: Tube DIY Asylum, Re: Ping: MQRACING (0.00)
Posted by Gary Kaufman on 2005-02-21, 06:52:57 (69.163.45.49)
I have 211's mounted in front of FS-100's. My transformers are mounted with the bells to the sides. I have 1.5" of clearance between the laminations and the back edge of the 211 socket. There is no no .......
86: Tube DIY Asylum, Re: followup (0.00)
Posted by Gary Kaufman on 2005-02-19, 09:16:11 (69.163.45.49)
Sorry I didn't respond sooner, I had some surgery as was offline. You shouldn't need anything close to that amount of capacitance to get the B+ quiet. I'd try 20 - 40uf/channel max. An old octal base .......
87: Vintage Asylum, Re: Scott 299D failure (0.00)
Posted by Gary Kaufman on 2005-02-12, 19:27:05 (69.163.45.49)
Aldovan - Not to suggest something very simple, but do you have the speakers hooked up properly? It's been a while since I've played with a 299D, but most HH Scotts uses a somewhat strange setup with .......
88: Tube DIY Asylum, Re: 6AF4 / 6AF4A (0.00)
Posted by Gary Kaufman on 2005-02-08, 19:42:06 (69.163.45.49)
Please email me - your AA mail bounces... - Gary .......
89: Tube DIY Asylum, 6AF4 / 6AF4A (0.00)
Posted by Gary Kaufman on 2005-02-08, 07:57:05 (130.189.41.169)
Has anyone had experience with the 6AF4 / 6AF4A ? It's a cute UHF medium-mu triode, looks like it might bias up nicely as a driver. Plate voltage max is a bit low at 150v. Not much in the archives. I .......
90: Tube DIY Asylum, Re: 1N4007 HV for 211 B+ supplies (0.00)
Posted by Gary Kaufman on 2005-02-07, 10:12:12 (69.163.45.49)
I also had a pair of the Handwound 10K SE transformers. I'd bet strongly that they are your problem. Plus, putting close to 1Kv on the primary would scare the >heck I run a similar circuit with a chok .......
91: Tubes Asylum, Re: 5AR4 in Dynaco ST70 (0.00)
Posted by Gary Kaufman on 2005-02-07, 08:42:47 (69.163.45.49)
You can't tell anything with a 5Y3 in place. Voltages will be way low, the 5Y3 is running significantly over ratings etc. Put in the correct rectifier, measure voltages and then assess what else needs .......
92: Tube DIY Asylum, Nope, leave unconnected. (0.00)
Posted by Gary Kaufman on 2005-02-05, 18:43:00 (69.163.45.49)
An "internal connection" pin may be used by the manufacturer as a internal tie point. It should not be used for anything outside. Some older equipment would use non-connected pins as tie-points for ot .......
93: Tubes Asylum, Pair (0.00)
Posted by Gary Kaufman on 2005-02-04, 12:12:51 (130.189.41.169)
I'd go with a pair. Most commonly seen in audio gear as driver tubes in amps (eg, HH Scott stuff) or in tuners. In either case they would be more useful in a pair. Look at what the more experienced tu .......
94: Tubes Asylum, Re: 6U8A - Typical application - single or in pairs??? (0.00)
Posted by Gary Kaufman on 2005-02-04, 10:07:10 (130.189.41.169)
Not exactly a rare tube - a single tube wouldn't be worth the postage. Frankly, unless they are telefunken I'm not sure a pair would be worth the postage. - Gary .......
95: MagneQuest/Peerless Forum, Re: for something different.... (0.00)
Posted by Gary Kaufman on 2005-02-03, 15:20:33 (130.189.41.169)
I've had some stuff chromed a few years back. Most re-chrome shops could care less as to what is on the metal. They'll strip it themselves. They are also happy to fill extra holes etc. I have finally .......
96: Tubes Asylum, Try this... (0.00)
Posted by Gary Kaufman on 2005-02-03, 14:59:38 (130.189.41.169)
Link - they seem to have the manual for sale at a reasonable cost. The usual "no relationship" disclaimer applies :) .......
97: Tubes Asylum, Smart Man! (0.00)
Posted by Gary Kaufman on 2005-02-03, 09:25:21 (130.189.41.169)
There are so many underappreciated tubes - you've listed many of my favorites. Franky, the tubes that cause me the most grief are some of the small signal tubes that are getting scarce. Mostly the stu .......
98: Tube DIY Asylum, WE 350A (0.00)
Posted by Gary Kaufman on 2005-02-03, 08:24:33 (130.189.41.169)
WE350A is essentially a 807, very nice tube. Not quite as expensive as the 350B, but close. With WE, the difference between "A" and "B" versions can often be pretty significant. In this case, they ar .......
99: Tubes Asylum, Whoops, info is for a 45C, don't know if they are alike. (0.00)
Posted by Gary Kaufman on 2005-02-03, 08:14:07 (130.189.41.169)
Whoops, info is for a 45C, don't know if they are alike. .......
100: Tubes Asylum, How's your German? (0.00)
Posted by Gary Kaufman on 2005-02-03, 08:11:43 (130.189.41.169)
The site below has what you need. A rough translation from Systran is: The tube tester Taylor model 45C from England The photos to this equipment come from Hugo Sneyers, Belgium - again thank you to i .......
101: Tube DIY Asylum, Re: Teeny Amp (0.00)
Posted by Gary Kaufman on 2005-02-02, 16:58:21 (69.163.45.49)
Probably even a bit less, as I used 5K output's. - Gary .......
102: Tube DIY Asylum, Re: you have mail (nt) (0.00)
Posted by Gary Kaufman on 2005-02-02, 05:41:46 (130.189.41.169)
I'd also appreciate what you might share. 717A's are quite cute! - Gary .......
103: Tube DIY Asylum, Re: Teeny Amp (0.00)
Posted by Gary Kaufman on 2005-02-02, 05:35:15 (130.189.41.169)
I've played with a few: 1626, 6S4 and 6EM7 for starters. There are a few schematics and links on my website. .......
104: Tubes Asylum, Ok... (0.00)
Posted by Gary Kaufman on 2005-02-01, 12:38:31 (130.189.41.169)
Kevin's one of the good guys. Any seller who owns that tester can most likely spot these as a fake. The text also wreaks of hype - which would be unnecessary for real KT88's. The seller also tells you .......
105: Tubes Asylum, Re: What about Bendix 5751 ? (0.00)
Posted by Gary Kaufman on 2005-01-24, 18:09:45 (69.163.45.49)
SJ - Suspect you're right, but there really is a TE-42 bendix variant of the 5751. It's spec'd as a hard glass variant - like the 6900 or 6094. Sadly I've never seen one - but I'm lookin' :) - Gary :: .......
106: Tube DIY Asylum, 5998 / 7236 (0.00)
Posted by Gary Kaufman on 2005-01-24, 08:46:48 (69.163.45.49)
FB - Any good designs / schematics to suggest with the 5998, 6528 or 7236? I have a healthy quantity of all three. If only 6AS7/6080's were valuable. I could retire :) - Gary .......
107: Vintage Asylum, Re: The amp is a HH Scott 208 that has already had all the capacitors replaced (0.00)
Posted by Gary Kaufman on 2005-01-23, 19:40:44 (69.163.45.49)
The HH Scott 208 is a very "bare-bones" amp, essentially the back end of a HH Scott 355. Not a single switch to clean! Just a 5AR4 rectifier, pair of triode-pentode drivers (either 6GH8 or 6U8) and th .......
108: Tubes Asylum, Leads... (0.00)
Posted by Gary Kaufman on 2005-01-21, 07:08:26 (130.189.41.169)
The Systron-Donner (Fairchild) 6200B was really designed for transistor use, so you end up with tube sockets and filament wiring extending away from the tester. The lead wires to the socket have a lo .......
109: Tube DIY Asylum, Nope. (0.00)
Posted by Gary Kaufman on 2005-01-13, 06:12:08 (130.189.41.169)
Although similar structure, they are very different electrically. If you really can't locate a SV572-160 an 811A or 572 is actually much closer, but you'd have to rewire the plate lead (pin 2) to a pl .......
110: Tubes Asylum, Re: 6BL8's and the dynaco ST-70 (0.00)
Posted by Gary Kaufman on 2005-01-12, 11:32:20 (130.189.41.169)
The 6GH8 is a common substitute in the ST70, and was used in several aftermarket PCB's. The Russian 7199 is reportedly nothing more than a re-pinned 6GH8. I've personally never tried it, as I'm unlike .......
111: Tubes Asylum, Re: 45 ?? (0.00)
Posted by Gary Kaufman on 2004-12-30, 12:21:25 (130.189.41.169)
Nah, just Chinese 2A3's. Fairly common practice as Robert points out - I have a similar Radio shack tube that is really one of the military 5931's restamped as a 45. 2A3's actually work surprisingly w .......
112: Tube DIY Asylum, Ping! (0.00)
Posted by Gary Kaufman on 2004-12-30, 05:15:22 (130.189.41.169)
Jose' - I haven't had my coffee yet, so bear with me... To deal with the 866jr's you'll need a separate filament transformer. You'd need to pre-heat the 866jr's for 2-4 minutes before applying B+. Yup .......
113: Tubes Asylum, Re: Mesh Plate 280's or 380's? (0.00)
Posted by Gary Kaufman on 2004-12-29, 14:00:22 (130.189.41.169)
Yup, I have them by Cardon and CeCo. Nothing special sonically imho, but rather attractive. Often gassy... - Gary .......
114: Computer Audio Asylum, Re: Unsophisticated User; Streaming Radio; Quality; Hard Wire to Stereo; Etc. (0.00)
Posted by Gary Kaufman on 2004-12-27, 06:20:27 (69.163.45.49)
Willie - I had a similar sitution, and eventually settled on a Roku Device (M1000). A bit pricy ($199 is the best price I found) - but very attractive and works nicely. See the link below for some det .......
115: Tubes Asylum, Re: How about Gold Lion/Monarch KT88 (0.00)
Posted by Gary Kaufman on 2004-12-24, 08:13:13 (69.163.45.49)
$13.80/MP in a 1971 Lafayette Radio Electronics Catalog. A rather expensive tube - By comparison a Mullard 10M series 12AX7 was $2.45 and 7591A's were $1.40 each. Matched pairs of KT66's were $8.43 an .......
116: Tube DIY Asylum, Re: Has anyone tried acid cleaning tube pins? (0.00)
Posted by Gary Kaufman on 2004-12-22, 08:13:58 (130.189.41.169)
Pearl has a piece about pin cleaning on their website, linky below. I can't open it at the moment (this computer has an older version of acrobat), but I recall it was a very good summary. I often use .......
117: Tube DIY Asylum, Re: looking for a preamp tube, low mu, low rp (0.00)
Posted by Gary Kaufman on 2004-12-21, 20:14:08 (69.163.45.49)
I'll add another vote for the 12B4. It's one of my favorite linestage tubes. My current linestage is essentially a 250vdc B+, 10K plate and 1.5K cathode resistor bypassed with 100uf. Avoid the late mi .......
118: Tube DIY Asylum, Re: Looking for a good Push PULL DIY tube amp (0.00)
Posted by Gary Kaufman on 2004-12-21, 13:17:35 (130.189.41.169)
If you're looking to build your own as a first project, clone one of the common vintage tube kits. Look at something like a Heathkit Williamson (any of the W1 thru W4) or Eico HF87/89 for good sound a .......
119: Tubes Asylum, Reflow the PCB (0.00)
Posted by Gary Kaufman on 2004-12-16, 11:45:52 (130.189.41.169)
Reflow every solder joint on the PCB, this will fix the intermittent connection 99 % of the time. Take special care to resolder around the eyelets - Most Dynakits were soldered by amateurs and cold so .......
120: MagneQuest/Peerless Forum, Check your email (nt) (0.00)
Posted by Gary Kaufman on 2004-12-15, 09:25:11 (130.189.41.169)
(not much here) .......
121: Vintage Asylum, Re: two tricks to the HF-65 (0.00)
Posted by Gary Kaufman on 2004-12-14, 06:01:54 (130.189.41.169)
I have SAM's for the HF-65A, but I'm not sure what the differences between the "A" and "non-A" versions are? The "A" is a powered pre-amp, and as mark suspected is essentially 1/2 of a HF-85 ::: TOPIC .......
122: Tube DIY Asylum, Re: Where to find 7 segment VFD tubes? (0.00)
Posted by Gary Kaufman on 2004-12-13, 18:54:18 (69.163.45.49)
You're thinking of Numitron's like the DR-2000. Look at www.numitron.com Sphere carries them, as do many of the standard tube vendors. There's a link to Sphere on my website below. Be warned, they ca .......
123: Tubes Asylum, Re: Why not just leave this in? (0.00)
Posted by Gary Kaufman on 2004-12-13, 18:25:16 (69.163.45.49)
Diodes work fine in a TV7 for the 83, but don't replace the 5Y3 with silicon. Apparently the small current draw is necessary. This is per Alan Douglas' book on test equipment - which btw is an essenti .......
124: Tubes Asylum, Re: A Fellow Bostonian offers advice... (0.00)
Posted by Gary Kaufman on 2004-12-13, 18:20:20 (69.163.45.49)
Affectionately known as "you blew it" electronics - for the many dashes I've made there on a Sunday to replace a part I just destroyed. Mail order (Mouser, Digikey) is much cheaper, but for a small ne .......
125: Vintage Asylum, Re: LK-72 Problems narrowed down....Yes! (0.00)
Posted by Gary Kaufman on 2004-12-12, 06:00:47 (69.163.45.49)
Larry - Many of the can caps will still be fine, you might want to reform and test before just trashing it. If it is bad, consider rebuilding the can - it will be much neater. As modern caps are small .......
126: Vintage Asylum, Re: Continued with variac ......still have problems.... (0.00)
Posted by Gary Kaufman on 2004-12-11, 20:47:22 (69.163.45.49)
Larry - Check voltages - especially on the bias circuit. I'd bet either the selenium rectifier or the quad 75uf cap has failed. The LK72 draws filament voltage for V1/2/3 off of the bias circuit. If .......
127: Tubes Asylum, Re: I can replace a 7355 tube with a 7591 without modifications ??? (0.00)
Posted by Gary Kaufman on 2004-12-11, 20:35:48 (69.163.45.49)
The A500 may not be as easy to rebias as some amps. The filament voltages for V1/2/3 are obtained from the bias current (sort of a free source of clean DC). If you change the bias you may also have t .......
128: Tubes Asylum, Re: I can replace a 7355 tube with a 7591 without modifications ??? (0.00)
Posted by Gary Kaufman on 2004-12-11, 19:03:32 (69.163.45.49)
Aldovan - Just check pin 4. It is unused on the 7355 and is a second connection to the screen (along with pin 8) on the 7591. If the amplifier uses pin 4 as a tie point, you'll need to move that wirin .......
129: Tubes Asylum, Re: tube broken? dynaco mkiii (0.00)
Posted by Gary Kaufman on 2004-12-10, 21:17:41 (69.163.45.49)
More likely a coupling cap or poor socket connection. Retension sockets, swap the pair of output tubes. If it stays with the same socket it's the coupling cap. If it moves with the tube then probably .......
130: Tubes Asylum, Re: Yup - Essentially a 5V4. (0.00)
Posted by Gary Kaufman on 2004-12-10, 19:12:48 (69.163.45.49)
The 83V won't hurt anything, but the voltage drop is wrong, and I'm sure the calibration will be way off. While you're waiting for an 83 you can make an adapter that will work fairly well. Juse use a .......
131: Vintage Asylum, Re: Fisher FM-50B (0.00)
Posted by Gary Kaufman on 2004-12-10, 14:23:33 (130.189.41.169)
Rob - I have a Fisher FM50B, FM200B and R200. The FM50B is the least sensitive/selective but given a reasonably good signal performs (and sounds) very nice. Mine had a nasty habit of dropping a chann .......
132: Tubes Asylum, Re: it will be fine, modeled with 83 (0.00)
Posted by Gary Kaufman on 2004-12-10, 08:48:21 (130.189.41.169)
Ed - 500vdc/50ma should be easy - my B+ is 825vdc, at 120-200ma depending on bias. I don't think the current is nearly as much as an issue with the voltage. Probably 1/2 of the 866jr's I've tried arc .......
133: Tubes Asylum, Yup - Essentially a 5V4. (0.00)
Posted by Gary Kaufman on 2004-12-10, 03:22:16 (69.163.45.49)
Yup, as Brian points out, not at all a good substitute for the 83 in a Hickok circuit. The 83V is essentially a 5V4 on a 4 pin base. Save it for another project! .......
134: Tubes Asylum, Web address (0.00)
Posted by Gary Kaufman on 2004-12-10, 03:19:39 (69.163.45.49)
Nice page Jim - Someone should grab the Bendix 5839's - great tube at your price. If I didn't already have 20+ I'd take 'em. Identical to the 5852 except for filament voltage. Many military transforme .......
135: Tubes Asylum, Re: A few things. (0.00)
Posted by Gary Kaufman on 2004-12-09, 05:06:00 (130.189.41.169)
Interesting that others have had better luck with cap loading. With the 866jr's any cap loading caused dramatic flash-overs. My experience was bit better with 866A's or 394A's on a breadboard - but ch .......
136: Tubes Asylum, 866jr's (0.00)
Posted by Gary Kaufman on 2004-12-09, 04:36:47 (130.189.41.169)
The rectifiers are 866jr's - While attractive looking, as Ed points out below they can be a royal pain. They don't take on that glow until you draw moderate current thru them. Given children and pets .......
137: Tubes Asylum, Buy lots of fuses.... (0.00)
Posted by Gary Kaufman on 2004-12-08, 14:25:39 (130.189.41.169)
My experience with MV rectifiers is that you really can't cap load them at all. IMHO about the only choice is LCLC with a swinging/smoothing chokes (low DCR) and the smallest caps you can get away wi .......
138: Tube DIY Asylum, Search instead of posting in several groups.... (0.00)
Posted by Gary Kaufman on 2004-12-07, 03:43:04 (69.163.45.49)
It's been discussed many times - a quick search will help! (look at the getter rings...). - Gary .......
139: Tube DIY Asylum, Re: PP EL84 Amp (0.00)
Posted by Gary Kaufman on 2004-12-02, 18:10:43 (69.163.45.49)
I may be missing something (it's been a long day...) but the GEC 50W amp is a KT88 design. They did publish a 14w UL EL84 amp that used a EF86 in the front end, then a 12AT7. I can scan and email if y .......
140: Tube DIY Asylum, Re: tube based capacitance checker? (0.00)
Posted by Gary Kaufman on 2004-12-01, 12:54:08 (130.189.41.169)
Heathkit IT-11 or IT-28 (essentially identical). Nice bridge, fairly accurate. Tube based, and tests leakage up to 600vdc. Perfect tool for reforming lytic caps. 6AX4, 6BN8, 6E5. Sadly, most are in po .......
141: Tube DIY Asylum, Re: Actually, another question.... (0.00)
Posted by Gary Kaufman on 2004-12-01, 05:30:00 (130.189.41.169)
I wonder if Don used a 100uf Black Gate as the "Can cap" and has it in parallel with the 56uf Solen? That would make sense - my hunch is that the 56uf cap would be a bit light on filtering. In that ca .......
142: Tubes Asylum, Re: Scott 222b How to install 9 pin tube the right way in the socket, help (0.00)
Posted by Gary Kaufman on 2004-11-30, 07:11:33 (130.189.41.169)
You really can't get it wrong - 9 pin tubes are essentially "10 pins" in a circle, with one pin missing. .......
143: Tube DIY Asylum, Re: 7643 tester settings? (0.00)
Posted by Gary Kaufman on 2004-11-27, 07:03:31 (69.163.45.49)
Vince - No idea what the problem is. Perhaps someone else has an idea. The 7643 crosses to a E80CF or 6BL8 - all are 9AE pinouts. You might check the setting for a 6GH8. Although the bias, range and m .......
144: Tube DIY Asylum, Re: 7643 tester settings? (0.00)
Posted by Gary Kaufman on 2004-11-26, 20:10:08 (69.163.45.49)
Vince - I believe you can test it as a 6BL8 .......
145: Vintage Asylum, Re: Bogen AP-30 schematic wanted (0.00)
Posted by Gary Kaufman on 2004-11-25, 06:53:36 (69.163.45.49)
See your email! .......
146: Tube DIY Asylum, Re: EiClone HF87 amp (0.00)
Posted by Gary Kaufman on 2004-11-23, 15:24:57 (130.189.41.169)
Shannon is a great person, and provides tremendous support. He has PCB's for clones of the Dynaco ST35 and Eico HF87. Both are fairly true to the original circuit. PCB's are well made and quite thick .......
147: Tube DIY Asylum, Mercury? (0.00)
Posted by Gary Kaufman on 2004-11-22, 07:03:34 (69.163.45.49)
Steve - I believe that Mercury made many of them - emissions testers (with the tendency to call good tubes bad, certainly didn't hurt sales). Nice display piece, and probably useful for culling large .......
148: Tube DIY Asylum, Re: 5687 linestage pictures. (0.00)
Posted by Gary Kaufman on 2004-11-19, 14:16:33 (130.189.41.169)
Henry - Very nice looking project. I recently went to the 12B4 for exactly the issues that have been described. It's a great tube - lowish gain, low RP, single triode per tube, and dirt cheap. Just m .......
149: Tubes Asylum, Re: Toshiba 6L6GC (0.00)
Posted by Gary Kaufman on 2004-11-13, 09:55:07 (69.163.45.49)
My experiences were less positive. Admittedly, sample size was small (4 tubes total). Despite looking like a nice clone of the RCA they didn't hold up. I had problems with them going "red plate" easil .......
150: Vintage Asylum, Re: Big wax caps? (0.00)
Posted by Gary Kaufman on 2004-11-13, 09:49:16 (69.163.45.49)
The Philco used two large electrolytics (8uf I believe). The remainder of the chassis used the typical bakelite modules that Philco was famous for. They contained caps or resistors in a wax matrix. Re .......
151: Vintage Asylum, Re: From back then to eternity, ebay and a question... (0.00)
Posted by Gary Kaufman on 2004-11-11, 08:05:25 (130.189.41.169)
Probably no amp with electrolytic caps will make it 50 years without service. Ironically I rebuilt a 1932 Philco console recently, that still worked (albeit poorly) in original condition. It plays qu .......
152: Vintage Asylum, Re: Does anyone know what the difference are between the Heathkit W4AM and the Heathkit W4B (0.00)
Posted by Gary Kaufman on 2004-11-10, 17:13:27 (69.163.45.49)
Electrical differences are very minor. W4B added a pair of 10K resistors between each side of the filament tap and ground, and has an on/off switch. Also the fuse was moved so that it just fuses the p .......
153: MagneQuest/Peerless Forum, Re: WE407A? (0.00)
Posted by Gary Kaufman on 2004-11-08, 07:40:37 (69.163.45.49)
The 407A was pretty much an accident for me - I picked up a nearly full case of them at a hamfest for around $10 a few years ago. After I got home and picked out the ballast tubes that were also in th .......
154: MagneQuest/Peerless Forum, Re: WE407A? (0.00)
Posted by Gary Kaufman on 2004-11-07, 17:24:04 (69.163.45.49)
I've used the 407A (and the 2C51 as well). The basis of this design was on an Asian website. Sounds very nice imho, and is perhaps the only reasonably priced WE tube. The 20v is trivial to deal with, .......
155: Tube DIY Asylum, Re: Who has built Gary Kaufman's 6EM7 DC triode amp? (0.00)
Posted by Gary Kaufman on 2004-11-01, 19:33:44 (69.163.45.49)
Well, I've built it >grin I continue to use it as my office system, and remain pleased. Original tubes still test fine 2+ years later, and the NiMH AA's are still going strong. It's so simple that you .......
156: Tube DIY Asylum, Re: 7189 or 7189A (0.00)
Posted by Gary Kaufman on 2004-10-31, 12:41:55 (69.163.45.49)
The HH Scott 208 uses 7591's, not 7189's. Indeed for 7591's the "A" version was a minor change and not an issue in replacing tubes. Great amp btw. .......
157: Vintage Asylum, Thanks! (nt) (0.00)
Posted by Gary Kaufman on 2004-10-31, 12:32:53 (69.163.45.49)
No text... .......
158: Vintage Asylum, Fisher 80-AZ (0.00)
Posted by Gary Kaufman on 2004-10-30, 14:11:30 (69.163.45.49)
I've just re-capped a second Fisher 80AZ and it came up to voltage nicely. Unfortunately the neon peak power indicator isn't working properly (it's on all the time). Anyone have a schematic or servic .......
159: Tube DIY Asylum, Re: 807's triode connected... (0.00)
Posted by Gary Kaufman on 2004-10-27, 07:04:25 (130.189.41.169)
I have the Heathkit WA-1 schematic if you need a copy. Email me privately. .......
160: Tubes Asylum, Re: EL34 identification... (0.00)
Posted by Gary Kaufman on 2004-10-25, 11:14:56 (69.163.45.49)
Aldovan - Looks like this guy printed up tons of RSD boxes and is remarking tubes. EL34's look Chinese, GZ34's are Russian 5Z4GT's etc. .......
161: Tube DIY Asylum, Re: MONSTER AEROVOX CAP (0.00)
Posted by Gary Kaufman on 2004-10-22, 15:49:45 (69.163.45.49)
Dan - esssurplus (a nice outfit btw, just a few miles from my qth) has some of the MKP1.44/3 120uf/750vdc versions of this monster cap on Ebay currently. I was turned onto these rather impressive caps .......
162: Tube DIY Asylum, Looking for Anthony Naso (0.00)
Posted by Gary Kaufman on 2004-10-20, 19:24:00 (69.163.45.49)
After a recent exchange of emails I recently sent off some active crossover boards to an Anthony Naso of Ridgebury Road Slate Hill, NY 10973. Just after the tracking confirms delivery, he stopped ret .......
163: Tubes Asylum, Re: On 5881's (0.00)
Posted by Gary Kaufman on 2004-10-20, 13:39:45 (130.189.41.169)
I actually like the TungSol 5881 very much - but I'm not always in agreement with popular dogma. They sound pretty darn nice in the Heathkit W2/3/4 series. Anyone who doesn't like their TS5881's can s .......
164: Bottlehead Forum, Re: Preferred subs for EL37 ? (0.00)
Posted by Gary Kaufman on 2004-10-20, 09:06:44 (130.189.41.169)
PH - 6L6GC's work fine in the Fisher 500. I believe that the later 500's were shipped that way. .......
165: Tubes Asylum, Re: Gary, this tube has been used.... (0.00)
Posted by Gary Kaufman on 2004-10-20, 06:07:11 (130.189.41.169)
I'm sure Audionote knows their filament supply can handle the extra current requirements if they are suggesting the 5852. I've played around with the 5852 and also it's obscure cousin the 5839 (same t .......
166: Tubes Asylum, Re: Anyone hear the Heathkit W3A.. (0.00)
Posted by Gary Kaufman on 2004-10-20, 05:50:22 (130.189.41.169)
The Heathkit W1/2/3 are classic Williamson designs. W1 used a Peerless output transformer and 807's - triode wired on the earlier version and u/l on the later version. The W2 switched to TungSol 5881' .......
167: Tubes Asylum, Re: Does the Bendix 5852 need running in? (0.00)
Posted by Gary Kaufman on 2004-10-19, 05:30:30 (130.189.41.169)
The 5852 draws twice the filament current (1.2A vs .6A for the 6X5). There's a chance that what you're hearing is related to a change in B+ either from sagging filament voltage for the rectifier, or a .......
168: Tube DIY Asylum, Re: 5V rectifier at 6.3v? (0.00)
Posted by Gary Kaufman on 2004-09-21, 11:41:13 (130.189.41.169)
Probably less trouble to just grab some 6X4/6X5/6CA4 or any one of various damper diodes. If you can't find anything locally email me privately and I'll send something your way. - Gary .......
169: Vintage Asylum, Yup, dad was right! (0.00)
Posted by Gary Kaufman on 2004-09-21, 08:02:12 (130.189.41.169)
Per the Eico manual for the HF-12: "The temperature of the transformers in the HF-12 run at less than 195 degrees despite the fact that the safety limited is at a much higher 221 degrees F. Although 1 .......
170: Vintage Asylum, Fisher Brass Caps.... (0.00)
Posted by Gary Kaufman on 2004-09-21, 07:02:46 (130.189.41.169)
Any quick shipping source for the Fisher brass caps? - Gary .......
171: Tubes Asylum, Re: nice if un-registered that A-hole. (0.00)
Posted by Gary Kaufman on 2004-09-16, 14:26:54 (130.189.41.169)
Ed - Yeah, I filed a complaint to Ebay as well. Perhaps the pile of email prompted some action. Maybe we should all register "temporary" ebay names and bid them way up. Then he can try and get ebay to .......
172: Vintage Asylum, Grilles? (0.00)
Posted by Gary Kaufman on 2004-09-14, 14:05:53 (130.189.41.169)
Any chance you still have the lattice grille you've removed? I have one nice Valencia, and one with the grille missing. I'd be interested in one of your grilles if it were at all salvageable. - Gary : .......
173: SET Asylum, Fuses, we don't need no stinkin' fuses... (0.00)
Posted by Gary Kaufman on 2004-09-14, 09:09:56 (130.189.41.194)
We could always start a thread about NOS fuses. Hey, this 3AG has a really unique "mesh plate" structure. Then again, if you bypass the fuses with a 10 gauge teflon coated silver wire.... ::: TOPIC:: .......
174: Tube DIY Asylum, Re: Nixie DIY Kit? (0.00)
Posted by Gary Kaufman on 2004-09-11, 19:47:57 (69.163.45.49)
Are you looking for a nixie clock? I have made up PC boards for Mike Harrison's Nixie Clock (as pictured above, with some rather inexpensive wire leaded nixies) - very nice design, simple CMOS. All pa .......
175: Tubes Asylum, Some others.. (0.00)
Posted by Gary Kaufman on 2004-09-06, 09:11:44 (69.163.45.49)
Some octal dual triodes, can easily be strapped together: 6BX7, 6BL7 Also 6AS7, 6080 (low voltage ratings however) and the rest of the family including 6336, 6528. 6BX7 is very nice tube, and quite in .......
176: Tubes Asylum, Sonar? (0.00)
Posted by Gary Kaufman on 2004-09-06, 09:08:06 (69.163.45.49)
According to Sibley's book, two were used in Navy QCL 20-khz sonar. Listed manufacturers are Amperex,Cunningham,GE,National Union,RCA,Taylor,United Electronics and Westinghouse. I guess you can also .......
177: Vintage Asylum, Re: Acrosound Stereo 20/20 (0.00)
Posted by Gary Kaufman on 2004-09-02, 06:29:55 (130.189.41.169)
Peter - Perhaps I'm missing something, but it looks like C5 is a dual cap, with two sections 40uf and 60uf both with 450v values. I seem to recall the 20/20 used a twist mount 1 3/8" originally, but y .......
178: Tube DIY Asylum, Re: Tantalex caps? (0.00)
Posted by Gary Kaufman on 2004-09-01, 07:26:17 (130.189.41.169)
Just curious - Why? I've heard this for years (and have never tried them myself). Are they really any worse than electrolytics? How about for power supply bypass/filtering? Why are tantalum caps so po .......
179: Tubes Asylum, National/Richardson (0.00)
Posted by Gary Kaufman on 2004-08-31, 08:41:27 (130.189.41.169)
G - AFAIK, National marketed two type of tubes rebranded as 5AR4's. The first is a Russian type, reportedly a 5Z4. They won't stand up as 5AR4's. Ironically, the second is actually a Bendix 6106. It .......
180: Tubes Asylum, Re: 5993 rectifier tube same as 6X4? (0.00)
Posted by Gary Kaufman on 2004-08-30, 10:14:39 (69.163.45.49)
Bendix 5993's are great tubes, and are in the 6X4 family. Then again, you have about as good a chance plugging a 6X5 octal into the socket for a 6X4 :) While the 5993 has 6X4 like ratings, it is a 9 p .......
181: Tube DIY Asylum, Why not just use a 807 or 1625? (0.00)
Posted by Gary Kaufman on 2004-08-25, 10:32:47 (130.189.41.169)
Or even a 6BG6. Except for filament and basing (and the plate cap) are virtually identical to a 6L6 and will be much happier at 550v. 1625's are a real sleeper. Dirt cheap, and beautiful NOS. Essentia .......
182: Vintage Asylum, Re: Looking for Eico HF-52 schematic (0.00)
Posted by Gary Kaufman on 2004-08-23, 13:15:41 (69.163.45.49)
Rodney - Email me, I've got a copy of what ya' need. Very Very nice amplifier btw, I have a pair. - Gary .......
183: Vintage Asylum, Re: IF the Old Man has it... (0.00)
Posted by Gary Kaufman on 2004-08-23, 13:10:04 (69.163.45.49)
Mark - Don't bother your dad, I have a copy and can help. - Gary .......
184: Vintage Asylum, Re: Fisher X100b schematic wanted (0.00)
Posted by Gary Kaufman on 2004-08-23, 09:27:40 (69.163.45.49)
Actually that's a "standard" Fisher trick. The 7868's generate 42v at the cathode, perfect to run a string of 4 x 12v tubes. The tubes see about 10.5v each across the filament, enough to run nicely. E .......
185: Tubes Asylum, Made in Chian! (0.00)
Posted by Gary Kaufman on 2004-08-23, 09:01:01 (69.163.45.49)
Here's another peach... Gosh, where's Chian. Must have learned geography from GWB. .......
186: Vintage Asylum, Re: Please help identify transformers (0.00)
Posted by Gary Kaufman on 2004-08-22, 16:14:46 (69.163.45.49)
As Jimmy points out, the TRA-8-5-1 are from HH Scott. See John Byrn's site at http://users.rcn.com/jbyrns/AmpSpecs.html for specific infomation as to which units they may have come from (222c/d or LK4 .......
187: Tubes Asylum, Re: Shipping cost to hong Kong (0.00)
Posted by Gary Kaufman on 2004-08-21, 11:55:26 (69.163.45.49)
You might try and find someone in the usa to cross-ship. I have a few overseas folks that I've gotten to know over the years and will accept packages for. When you encounter a rediculous shipping cost .......
188: Vintage Asylum, Bogen CHB-50 CHB100 (0.00)
Posted by Gary Kaufman on 2004-08-20, 06:53:00 (130.189.41.169)
Anyone have a schematic for the Bogen CHB-50, or experience with the CHB-50 and CHB-100 amps? I've been offered both, and am deciding between restoring (they have no 7868's) or using the iron for a mo .......
189: Tube DIY Asylum, Re: Workbench Tips (0.00)
Posted by Gary Kaufman on 2004-08-20, 05:41:31 (130.189.41.169)
I'd second Vinnie's comments. A wooden pallet covered by some old carpet is perfect to keep you isolated from the floor. My first "real" workshop was in a cellar. I almost ended my hobby by standing .......
190: Tube DIY Asylum, Re: Help! needed on new 6EM7 amp... (0.00)
Posted by Gary Kaufman on 2004-08-20, 05:33:22 (130.189.41.169)
ER - The cathode resistor is dissipating around 7.3w, so a 10w resistor is a bit close but should be ok. I originally used 1.5K/1.3K 10w resistors in series, so really a 20w resistor. Also the grid on .......
191: Tube DIY Asylum, Re: 211 slow warm-up??... (0.00)
Posted by Gary Kaufman on 2004-08-19, 10:44:21 (130.189.41.169)
With Altec A-5's it was a bit too much for my taste. I ended up using a "poorly filtered" DC on the 211's as a compromise. - Gary .......
192: Tube DIY Asylum, Re: 211 slow warm-up??... (0.00)
Posted by Gary Kaufman on 2004-08-19, 06:32:38 (130.189.41.169)
Here's the schematic and linky to PAE's site (nice site, with lots of good info btw). My power supply is very different, and I used a lower B+. The ACRO TP-550 I used is pretty uncommon, so you'd pro .......
193: Tube DIY Asylum, Re: 211 slow warm-up??... (0.00)
Posted by Gary Kaufman on 2004-08-18, 14:26:28 (130.189.41.169)
Mike - You might even try the oil as the first cap. I don't know why, but I've been impressed that the first cap is way more critical. Perhaps it "sees" more of the ripple in that position. ::: TOPIC .......
194: Tube DIY Asylum, Re: 211 slow warm-up??... (0.00)
Posted by Gary Kaufman on 2004-08-18, 13:45:04 (130.189.41.169)
Mike - My 211 is based heavily on PAE's design, with a 6C45 choke loaded and driving the 211 thru an oil cap. Output and chokes are from Magnequest. The power supply is a bit strange design with an AC .......
195: Tube DIY Asylum, Re: 211 slow warm-up??... (0.00)
Posted by Gary Kaufman on 2004-08-17, 14:07:41 (130.189.41.169)
Mike - I've never noticed that in my 211 amp - i'd be curious as to what your driver/ps design is. There aren't many physical differences between the 211/845 - AFAIK only the winding of the grid is di .......
196: Tubes Asylum, Wunderlich! (0.00)
Posted by Gary Kaufman on 2004-08-17, 08:23:08 (130.189.41.169)
The Arcturus Wunderlich gets my vote - blue glass, red base and globe shape. Bill's website at http://www.bill01a.com has some of the most amazing tube pic's I've ever seen btw. Great eye candy. I al .......
197: MagneQuest/Peerless Forum, And good luck getting paid.... (0.00)
Posted by Gary Kaufman on 2004-08-17, 03:52:46 (69.163.45.49)
Their website redirects to a site with all of the typical "accept content from" and "set my homepage to" sort of pop-ups. .......
198: Tubes Asylum, 5R4? (0.00)
Posted by Gary Kaufman on 2004-08-17, 03:46:43 (69.163.45.49)
Looks like a 5R4. If it's directly heated, and draws 2A@5V it's probably a 5R4, if it draws 3A@5V it's probably a 5U4 (although they don't typically have the taller base style). .......
199: Tube DIY Asylum, Re: Power Transformer for Preamp (0.00)
Posted by Gary Kaufman on 2004-08-16, 15:03:58 (69.163.45.49)
If you're looking to breadboard, look into the various iterations of Heathkit's bench supply. The PS-4, IP-32, SP-17A, IP-17A and IP-2717 are all essentially the same circuit in various incarnations. .......
200: Tube DIY Asylum, Same as 1000T? (0.00)
Posted by Gary Kaufman on 2004-08-14, 13:02:44 (69.163.45.49)
Jim - If the 1000T is the same data, I can help... .......
201: Tubes Asylum, Date code? (0.00)
Posted by Gary Kaufman on 2004-08-14, 07:04:42 (69.163.45.49)
Probably just a date code, unless your preamp really uses a 25kv PIV, 2A Hydrogen Thyratron.... .......
202: Vintage Asylum, Re: Tube picks help X-202 (0.00)
Posted by Gary Kaufman on 2004-08-13, 14:02:05 (130.189.41.169)
Were there any original tubes in the unit? It would be very rare for all to need replacement, and the originals were usually of better quality than most any current production. .......
203: SET Asylum, Power transformer... (0.00)
Posted by Gary Kaufman on 2004-08-13, 11:30:31 (130.189.41.169)
Hammond has two that would work nicely: 374BX 200VA, 375-0-375 @ DC ma 175, 5VCT @ 3A, 6.3VCT @ 6A. 274BX 198VA, 375-0-375 @ DC ma 175 5VCT @ 3A, 6.3VCT @ 6A. The 300 series have universal primaries ( .......
204: Tubes Asylum, How about "like all vintage items, sold as-is"? (0.00)
Posted by Gary Kaufman on 2004-08-13, 06:50:52 (130.189.41.169)
All vintage items are not as-is! Frankly, if I want to buy something "as-is" I'll shop at a flea-market or garage sale! .......
205: Tube DIY Asylum, Selenium Rectifiers - Toxic too! (nt) (0.00)
Posted by Gary Kaufman on 2004-08-12, 14:20:35 (130.189.41.169)
not much here.... .......
206: SET Asylum, A monoblock (nt) (0.00)
Posted by Gary Kaufman on 2004-08-12, 14:15:20 (130.189.41.169)
not much here... .......
207: Vintage Asylum, Re: Questions about Vintage tube DIY project (0.00)
Posted by Gary Kaufman on 2004-08-12, 14:13:43 (130.189.41.169)
Dave - The basic power amps are clearly the easiest to work on - especially those that were originally sold as kits. The availability of construction manuals and troubleshooting hints can be a great h .......
208: SET Asylum, Solen's work nicely (0.00)
Posted by Gary Kaufman on 2004-08-12, 13:17:31 (130.189.41.169)
Solens work nicely, or motor run / oil caps if you have the space required. I built this several years ago, but recall I did eventually strap a 100uf/450v axial lytic cap across the power supply (afte .......
209: SET Asylum, JC's Micro 3.5 (0.00)
Posted by Gary Kaufman on 2004-08-12, 06:20:03 (130.189.41.169)
JC's Micro 3.5 is about as simple as you can get for a VERY good sounding 2A3 amp - and a very good first project. In a lower power range, Gordon Rankin's Bugle 45 is another spectacular sounding amp. .......
210: Tube DIY Asylum, K1/K2 = Relay (0.00)
Posted by Gary Kaufman on 2004-08-09, 10:59:35 (69.163.45.49)
Probably to mute the outputs at turn-on. There is usually a delay circuit (a pair of transistors and a R/C delay). - Gary .......
211: Dynaco-Doctor Forum, EM84 in FM3 - Yup! (0.00)
Posted by Gary Kaufman on 2004-08-06, 12:58:14 (130.189.41.169)
Turns out that Dynaco suggested exactly that - once the EMM801 became unobtanium. I have a copy of the tech memo here. It is a bit of re-wiring, but works nicely. You lose the stereo beacon (not a big .......
212: Tubes Asylum, Answering my own question... (0.00)
Posted by Gary Kaufman on 2004-08-03, 18:38:44 (69.163.45.49)
Turns out there's a typo - should be HS5-0830. .......
213: Tubes Asylum, Testing 8068's (0.00)
Posted by Gary Kaufman on 2004-08-03, 18:32:47 (69.163.45.49)
Anyone have test settings for the 8068 for either TV7, 539B/C, I177B or Eico 667 testers? The settings listed in Nolan Lee's table for the TV7 (HS5-0380) doesn't appear to work. Many thanks! ::: TOPIC .......
214: Tube DIY Asylum, I think Jimmy is correct.... (0.00)
Posted by Gary Kaufman on 2004-08-03, 12:04:46 (130.189.41.169)
Douglas - I think Jimmy is correct, the 866JR takes less filament current, 2.5A by most spec sheets (although I've seen 3A on one website). They are very pretty, although I've had problems with the o .......
215: Tube DIY Asylum, Congrats! (0.00)
Posted by Gary Kaufman on 2004-08-03, 10:10:57 (130.189.41.169)
Henry - Good work! My rebuilt Daven is still on my workbench, waiting for a suitable host. While not a project for the timid, they are pretty straight-forward to rebuild once that pesky pin yields. If .......
216: Tubes Asylum, Re: You aren't the only one... (0.00)
Posted by Gary Kaufman on 2004-08-03, 09:51:48 (130.189.41.169)
I very much agree. The 6AR6/6098 is very good sounding, and still quite available. One of these days I'll work on a better driver for the "guided missle" amp, but it does sound fairly nice and is rath .......
217: Tubes Asylum, You aren't the only one... (0.00)
Posted by Gary Kaufman on 2004-08-03, 07:30:47 (130.189.41.169)
Good luck! I've also been looking for 6889's and have turned up 2 in 8+ years of looking... They appear to be far scarcer than 6384's and certainly not less expensive. .......
218: Tube DIY Asylum, Re: Power supply HELP !!!! (0.00)
Posted by Gary Kaufman on 2004-08-01, 06:31:15 (142.131.77.139)
Aldovan - Download the power supply design tool from Duncan Amps (www.duncanamps.com) and simulate your power supply. You can then try various changes easily. It's a tremendous program, and best of al .......
219: Tubes Asylum, Re: Dynaco transformers (0.00)
Posted by Gary Kaufman on 2004-07-31, 12:52:00 (142.131.77.139)
Download the Dynaco transformer catalog below, should help with your questions! .......
220: Tube DIY Asylum, Hardly a guru, but a few ideas... (0.00)
Posted by Gary Kaufman on 2004-07-27, 18:26:31 (69.163.45.49)
I'm also still just a neophyte in the world of higher B+. I've found that the best resource is older copies of the Radio Amateur's Handbook from the ARRL. Issues from the 1950's and 1960's are ideal. .......
221: Tube DIY Asylum, Disagree away, no hard feelings.... (0.00)
Posted by Gary Kaufman on 2004-07-27, 10:44:38 (130.189.41.169)
I'd rather see a vintage amp preserved nicely, then botched by someone who felt a need to install 12 gauge wiring for a linecord. I haven't seen the Quad II for many years, but recall that it has a sm .......
222: Tube DIY Asylum, Re: Power cable upgrade for vintage tube amp? (0.00)
Posted by Gary Kaufman on 2004-07-27, 05:48:52 (130.189.41.169)
Despite audio-neurotic behavior, most amplifiers don't draw any more current than a "three-way" table lamp. From an purely electrical standpoint, even 20 gauge wire is overkill on a 6' cord feeding mo .......
223: Radio Road, Re: Furthest range of WGBH FM Boston--S.Maine? VT? W. Mass? (0.00)
Posted by Gary Kaufman on 2004-07-23, 16:23:24 (130.189.41.194)
I can receive WGBH nicely in Southern NH (I'm about 10 miles west of Nashua) in my home, but not reliably in a car. It takes a modestly good tuner, but nothing spectacular. A Fisher FM-200 or HH Scott .......
224: Tube DIY Asylum, Try this, works well... (0.00)
Posted by Gary Kaufman on 2004-07-23, 10:04:37 (130.189.41.169)
http://www.systransoft.com/ translates the webpage nicely! .......
225: Vintage Asylum, Re: Help! Need the Spec of Mcintosh MC60 choke (0.00)
Posted by Gary Kaufman on 2004-07-22, 14:24:51 (69.163.33.243)
M-174: 1.84H, 37.5 ohms, .116A rating Listed substitues are Merit C2974, Stancor C-2325, Triad C17x, Thordarson 26C43 (all have different mounting bracket spacing). - Gary .......
226: Tube DIY Asylum, Re: Timer Relay (0.00)
Posted by Gary Kaufman on 2004-07-20, 11:11:51 (130.189.41.169)
A reasonable concern, but I think it's just fine. The relay contacts only "see" the voltage across the 1K resistor - not the entire B+. The relay is rated for 1000vac insulation between contacts and .......
227: Tube DIY Asylum, Re: 5Y3GT ramp-up (0.00)
Posted by Gary Kaufman on 2004-07-20, 09:24:47 (130.189.41.169)
Eli - Just curious - do the Raytheon 6087's have the typical GE etched markings? - Gary .......
228: Tube DIY Asylum, Timer Relay (0.00)
Posted by Gary Kaufman on 2004-07-20, 07:26:55 (130.189.41.169)
Jimmy - If you like a relay delay, look at CPS152 at www.electronics123.com It's a cute delay board that is easily adjustable and fairly inexpensive. I've used it several times with good success. If y .......
229: Vintage Asylum, Re: Heathkit W-5M (0.00)
Posted by Gary Kaufman on 2004-07-20, 07:07:10 (130.189.41.169)
Tom - Actually I believe you need to jumper 6 - 7 to turn on. Pin 8 goes to the switched socket. Also a warning to the original post - Every very single W5M I've seen had significant issues that neede .......
230: Tubes Asylum, Also true of the 5AR4's (0.00)
Posted by Gary Kaufman on 2004-07-20, 05:23:19 (130.189.41.169)
The Japanese made 5AR4's are excellent copies of the Mullard, and perform well. They are often far less expensive. The Toshiba 7591's I've owned also performed nicely. The one exception is the 6L6GC. .......
231: Tube DIY Asylum, Re: 5Y3GT ramp-up (0.00)
Posted by Gary Kaufman on 2004-07-20, 05:08:10 (130.189.41.169)
As Bas points out, the 5Y3 is directly heated and will provide B+ almost instantly. There are a few 5Y3 "varieties" that are indirectly heated. The Bendix 6106 has a tremendously long warm up time. Th .......
232: Tubes Asylum, Re: Further Question on Power Transformer (0.00)
Posted by Gary Kaufman on 2004-07-15, 09:29:45 (130.189.41.169)
Mechanical buzzing from ST70 transformers is not all that uncommon. You can try to tighten the bolts a bit, or mechanically isolate the transformer from the chassis with some rubber washers. If you c .......
233: Tubes Asylum, Re: EL 509/519 or 6KG6 Recomendations (0.00)
Posted by Gary Kaufman on 2004-07-15, 09:23:28 (130.189.41.169)
PL509 = 40KG6 EL509 = 6KG6 I'm not sure of the exact differences between EL509/EL519 but I believe the two types are essentially interchangable. .......
234: Tube DIY Asylum, Date Code? (0.00)
Posted by Gary Kaufman on 2004-07-12, 05:01:34 (69.163.33.243)
Vince - Sure this isn't a date code? There is no 8235 listed in any of my sources. .......
235: Tubes Asylum, Re: Tubes and airport security (0.00)
Posted by Gary Kaufman on 2004-07-09, 06:24:00 (216.204.13.235)
I've done it many times, you probably won't have any problems. I've had more problems with oil capacitors, which apparently look rather concerning on xray. A few years before 9/11 I was returning from .......
236: Tubes Asylum, What are snivets? (0.00)
Posted by Gary Kaufman on 2004-07-08, 14:22:27 (130.189.41.169)
I was just looking at the GE Data sheet on the 6JN6 beam pentode. The data sheet reports that ...A separate connection is provided for the beam plates to minimize "snivets". I would assume that this i .......
237: Tube DIY Asylum, The end of analog? (0.00)
Posted by Gary Kaufman on 2004-07-08, 12:13:10 (130.189.41.169)
Nice piece on NPR yesterday morning on the end of analog tape. "Fans of reel-to-reel tape prefer its sound quality, but few companies still make analog tape machines -- let alone the tape. NPR's Rick .......
238: Tube DIY Asylum, Would be a nice transformer for many uses (0.00)
Posted by Gary Kaufman on 2004-07-07, 20:43:31 (69.163.33.243)
A PA-135 clone would be a nice transformer for many uses, especially if you'd consider adding a second set of B+ taps at something a bit lower like 275v. Then it would be ideal for Mark IV replacement .......
239: Tube DIY Asylum, Thanks for the compliment, but... (0.00)
Posted by Gary Kaufman on 2004-07-07, 08:11:36 (130.189.41.169)
I've never seen published specs for the PA-135. What I do know is that it is: 370-0-370 @ at least 120ma with a bias tap probably at 100v 5v @ at least 2A (runs a 5AR4) 6.3v @ at least 3.5A (runs a pa .......
240: Tubes Asylum, Sure, RF and IF amplifiers! (0.00)
Posted by Gary Kaufman on 2004-06-27, 07:43:27 (69.163.33.243)
Probably a pretty poor audio tube, which I suppose is what you were really wondering. Remote cut-off. .......
241: Tube DIY Asylum, Re: There is a way in (0.00)
Posted by Gary Kaufman on 2004-06-26, 06:34:33 (69.163.33.243)
Carlos - Thanks again, with your help I now have a very nice 100K Log attenuator instead of the (somewhat useless to me) 20M linear. .......
242: Tube DIY Asylum, Re: I tried again this morning. (0.00)
Posted by Gary Kaufman on 2004-06-26, 05:50:40 (69.163.33.243)
Henry - I did successfully get my potentiometer open last nite, and was able to substitute resistors to get a 100K log taper with 60db total (the original was a 20 step / 60db 20M dual) Actually I was .......
243: Tube DIY Asylum, Thanks! (0.00)
Posted by Gary Kaufman on 2004-06-24, 03:48:46 (69.163.33.243)
Carlos - Thanks, I'll give it a try. I wasn't looking to "upgrade" the resistors, but the 20M potentiometer isn't of much use to me. I was hoping to re-do the steps as perhaps a 100K audio taper. ::: .......
244: Tubes Asylum, Shuguang / SuperTNT 845B Tubes (0.00)
Posted by Gary Kaufman on 2004-06-23, 14:07:01 (130.189.41.169)
Nice review Ed! Where'd you get that cheezy curve tracer ... - Gary .......
245: Tube DIY Asylum, DIY.... (nt) (0.00)
Posted by Gary Kaufman on 2004-06-22, 13:30:53 (130.189.41.169)
Not much here, really .......
246: Tube DIY Asylum, Re: Daven Attenuators (0.00)
Posted by Gary Kaufman on 2004-06-22, 11:02:07 (130.189.41.169)
Henry - I was hoping there was an easy solution. Did you ever try driving/drilling out the small pin through the shaft end? - Gary .......
247: Tube DIY Asylum, Daven Attenuators (0.00)
Posted by Gary Kaufman on 2004-06-22, 07:22:14 (130.189.41.169)
Has anyone figured out how to disassemble the Daven 20 step stereo attenuators. I picked up a 20meg unit, and would like to re-do the steps for a more useful value. There doesn't seem to be an obvious .......
248: Hi-Rez Highway, Re: The donut or the hole? (0.00)
Posted by Gary Kaufman on 2004-06-19, 16:01:25 (69.163.33.243)
Can you tell me more about the "buy back"? My C555ES just started failing on Redbook as well, and I'm planning to bring it in for service early this week. Was your unit not repairable? .......
249: Tubes Asylum, Re: Tube porn? (0.00)
Posted by Gary Kaufman on 2004-06-19, 08:43:47 (69.163.33.243)
A few years ago, when I was still using one of the free hosting services I started posting a "tube centerfold" of the month. After a few months, my service was abruptly discontinued because they had s .......
250: Tube DIY Asylum, Try JC's "Micro 3.5" 2A3 design. (0.00)
Posted by Gary Kaufman on 2004-06-16, 13:36:52 (130.189.41.169)
Try JC's "Micro 3.5" 2A3 design from Sound Practices. Very similar sonics to the 6EM7 (imho) and a bit more power. Still pretty easy to construct (6SL7 driving 2A3), Sovtek 2A3's work perfectly in thi .......
251: Tube DIY Asylum, 866jr (nt) (0.00)
Posted by Gary Kaufman on 2004-06-16, 12:10:43 (130.189.41.169)
well, actually not much text... .......
252: Tube DIY Asylum, Re: 83's with phono stage? (0.00)
Posted by Gary Kaufman on 2004-06-14, 18:45:59 (69.163.33.243)
Admittedly I've only used mv rectifiers with power amps, but they presented some challenges in layout and filtering to get them to stop feeding RF. I guess I just feel that a nice indirectly heated re .......
253: Tube DIY Asylum, Re: Ground Loops and Ground Lifter Switches. . . (0.00)
Posted by Gary Kaufman on 2004-06-14, 18:34:09 (69.163.33.243)
I've occasionally used a 10 ohm resistor between ground and chassis in linestages, worked nicely for me. Although I haven't tried it personally, I've heard the trick of placing a pair of diodes back-t .......
254: Tube DIY Asylum, 83's with phono stage? (0.00)
Posted by Gary Kaufman on 2004-06-13, 10:06:39 (69.163.33.243)
I've also just received a few of their bare PC boards, but haven't constructed any yet. I have their 6SN7 linestage PCB, the LS-37 phonostage and 5687 headphone amp board. Shipping was prompt, and ema .......
255: Tubes Asylum, Now, can we find a use for 1B3's ?? (0.00)
Posted by Gary Kaufman on 2004-06-08, 14:06:36 (130.189.41.169)
I'm convinced, theres a gremlin that tosses a few 1B3's and 6AL5's into every box of tubes just before I look inside. I'm starting to wonder if 1B3's would make a good fuse... - Gary .......
256: Tubes Asylum, Re: "Are there any Really useless tubes?" (0.00)
Posted by Gary Kaufman on 2004-06-08, 10:10:53 (130.189.41.169)
Douglas - Apparently they were being used in some xray lithography/IC manufacturing equipment. .......
257: Tubes Asylum, Most overused word on Ebay.... (0.00)
Posted by Gary Kaufman on 2004-06-08, 07:20:31 (130.189.41.169)
Obviously I should be doing something useful, but currently 745,721 items on ebay are "rare", 8,674 are "rarest" and 41,156 are "extremely rare". Then again, "Museum Quality" racks up 17,599 hits, and .......
258: Tubes Asylum, Good Luck! (0.00)
Posted by Gary Kaufman on 2004-06-07, 10:27:02 (69.163.33.243)
KT77's must be one of the less common tubes to show up on the market imho, especially in the USA. In many years of collecting tubes I've run into only one example, and it's pretty worn. TubeWorld has .......
259: Tubes Asylum, Re: 7868 testing (0.00)
Posted by Gary Kaufman on 2004-06-04, 10:57:39 (130.189.41.169)
Bunt - 7868 is novar (9 pin compactron) 6GM5 is a minature 9 pin base with a larger T-9 bulb. Relatively uncommon format, also used with some 6EW7's and 6FD7's etc IIRC. 9 pins can get confusing betwe .......
260: Tubes Asylum, Re: What is a good cheap tube tester for 7868 Novars? (0.00)
Posted by Gary Kaufman on 2004-06-04, 10:06:09 (130.189.41.169)
Inexpensive = Emissions Eico 667 is one reasonable choice that will test all types you've listed. Actually it's a variety of an emissions tester called "Dynamic Mutual Conduction". Otherwise, any test .......
261: Tubes Asylum, Re: Anyone tried those solid state 83 tube replacements for Hickok? (0.00)
Posted by Gary Kaufman on 2004-06-03, 11:11:26 (130.189.41.169)
They work fine in a TV7, calibration seems perfect. Make your own - 2 1N40007's, scrap 4 pin tube base, and a pair of 10 ohm 1 watt resistors. .......
262: Tube DIY Asylum, 6005 (0.00)
Posted by Gary Kaufman on 2004-05-29, 14:06:50 (69.163.33.243)
You're thinking of the 6005. 6006 is a 6SG7 equivalent. .......
263: Tube DIY Asylum, Re: Output power of Gary K's 6EM7 amp? (0.00)
Posted by Gary Kaufman on 2004-05-21, 13:27:35 (130.189.41.169)
Honestly I've never measured it, but was of the impression it was around twice what you've found. My amp is at work, but if I get a some free time I'll drag it home and see what I get for measurements .......
264: Tube DIY Asylum, Re: Does Anyone Have Access to VTV Issue # 11 and/or a way of Uploading the VTV 6SN7 Octal L.S. Schematic? (0.00)
Posted by Gary Kaufman on 2004-05-21, 13:24:51 (130.189.41.169)
Look at the linky below... .......
265: Tube DIY Asylum, Re: A book I 'd never heard of came up on Ebay.... (0.00)
Posted by Gary Kaufman on 2004-05-19, 06:37:32 (130.189.42.129)
Mark - Could you email me privately when you get a chance. .......
266: Tube DIY Asylum, Lightning Strikes... (0.00)
Posted by Gary Kaufman on 2004-05-18, 10:07:58 (130.189.41.169)
My front yard was struck by lightning Saturday nite. Interestingly the strike was to a small gauge wire that crosses my driveway as part of an abandoned invisible dog fence. The strike missed all of t .......
267: Tubes Asylum, Looks llike a Sylvania (typical supplier for Philco) (nt). (0.00)
Posted by Gary Kaufman on 2004-05-11, 07:06:10 (130.189.41.169)
2A3 looks like a Sylvania (typical supplier for Philco). .......
268: Tubes Asylum, At least no one has been stupid enough to bid yet (nt) (0.00)
Posted by Gary Kaufman on 2004-05-10, 05:52:27 (69.163.33.243)
.......
269: Tube DIY Asylum, Re: 6HB5 (0.00)
Posted by Gary Kaufman on 2004-05-08, 08:48:07 (69.163.33.243)
Actually not that hard to locate, but $14-18 each. http://members.aol.com/etetubes/ http://www.tubesandmore.com http://www.vacuumtubesinc.com among others. .......
270: Tubes Asylum, Re: Arcturus 12BH7/any info? (0.00)
Posted by Gary Kaufman on 2004-05-07, 20:14:00 (69.163.33.243)
The original boxes from the 1920's and 1930's were dark blue on a white or orange creame color. The "Real" Arcturus made primarily "pre-registration" 4/5/6/7 pin tubes, often with blue glass. I don't .......
271: Tubes Asylum, Re: Arcturus 12BH7/any info? (0.00)
Posted by Gary Kaufman on 2004-05-07, 19:41:18 (69.163.33.243)
Arcturus "blue boxes" were all rebranded and could be anything from a major manufacturer to seconds to washed used. Occasionally you get nice surprises, occasionally junque. I believe the real Arcturu .......
272: Vintage Asylum, Looking for original Heathkit manuals (0.00)
Posted by Gary Kaufman on 2004-05-06, 19:44:37 (69.163.33.243)
I'm in the process of creating an "electronic archive" of some of the early Heathkit manuals. I'm specifically looking for: Williamson Series: W4, W6, W7 "A" series: A1, A2, A3, A4, A5, A6, A7 (except .......
273: Tube DIY Asylum, Re: recommended parts for dc darling 1626 amp (0.00)
Posted by Gary Kaufman on 2004-05-06, 13:12:19 (130.189.41.169)
Which version are you planning? Your link was to the "double DC darling", the DC-Darling is on Bob's site (link below). I rarely use anything smaller than 1/2 watt as I don't stock them, with that in .......
274: Tubes Asylum, Look at the auction (nt) (0.00)
Posted by Gary Kaufman on 2004-05-06, 04:58:00 (130.189.41.169)
.......
275: Tube DIY Asylum, Re: Bendix 5947/TT-2 (0.00)
Posted by Gary Kaufman on 2004-05-05, 18:15:08 (69.163.33.243)
Tubelore lists it as a rectifier, fil. 4.4V @ 1.75A .......
276: Tubes Asylum, Hey, did you know you could use a 5Z3 in your Hickok (not) (0.00)
Posted by Gary Kaufman on 2004-05-05, 13:56:06 (130.189.41.169)
Auction at the usual place, promoting a 5Z3 for an 83. While some 1N4007's work fine, a 5Z3 sure won't! .......
277: Tube DIY Asylum, Re: I have a ton of them (0.00)
Posted by Gary Kaufman on 2004-05-04, 06:11:37 (130.189.41.169)
Doubt you'll be very impressed by differences between 5Z3/5U4 sonically (at least I've never been impressed). If the ebay adapter goes for more than it's worth, they are trivial to build from a junke .......
278: Tube DIY Asylum, Sure, but why bother? (0.00)
Posted by Gary Kaufman on 2004-05-02, 20:31:04 (69.163.33.243)
Rick - Beautiful 5Z3's are easy to source, and inexpensive. Depending on your amp design you might also be able to try 83V's as a way to try an indirectly heated rectifier in the same socket/pinout. .......
279: Tubes Asylum, Re: I too am a novice..so take this.. (0.00)
Posted by Gary Kaufman on 2004-04-29, 18:00:26 (69.163.33.243)
Eric - As a first step, unplug all inputs and turn the input gain all the way down (essentially shorting out the inputs). If the hum goes away then Jim may be correct about a ground loop. If the hum p .......
280: Tube DIY Asylum, Yeah! (nt) (0.00)
Posted by Gary Kaufman on 2004-04-21, 14:31:22 (130.189.41.169)
.......
281: Tube DIY Asylum, Re: Is this SETdistortion, PS noise or what??? 6em7 amp... (0.00)
Posted by Gary Kaufman on 2004-04-20, 07:16:32 (130.189.41.169)
I've used the 125ESE's with this design, so I doubt they are the problem. It is a You could try playing with the 120K resistor to adjust the grid voltage on the second triode section closer to 115v. I .......
282: Tubes Asylum, Re: Where to find OA2 tubes for Frist Sound Amp? (0.00)
Posted by Gary Kaufman on 2004-04-16, 08:18:11 (130.189.41.169)
Just curious, but per the website you referred to " We have a special quality type vacuum tube made for the Russian Military that can take a 3ma current draw." A standard 0A2 will regulate between 5 .......
283: Tube DIY Asylum, Re: Help with PS (0.00)
Posted by Gary Kaufman on 2004-04-15, 14:50:55 (130.189.41.169)
You could use most any 275-0-275v transformer at 100ma or more. I tend to like the 300 series of Hammond. They are designed for 50/60 cycle primaries and tend to be less prone to buzzing than the budg .......
284: Tubes Asylum, Re: Where to find OA2 tubes for Frist Sound Amp? (0.00)
Posted by Gary Kaufman on 2004-04-15, 07:39:03 (130.189.41.169)
OA2's are a very common 150v gas regulator tube, should be very easy to source thru any tube vendor. $4-5 tops. They last a long time, they are not all that different from a neon bulb. National is a r .......
285: Tube DIY Asylum, Re: Bell 2122-C Manual and Schematic Needed (0.00)
Posted by Gary Kaufman on 2004-04-13, 16:27:26 (69.163.33.243)
I have the SAM's Photofact, send along an email if you need a copy. Very cute little amp btw. .......
286: Tubes Asylum, Ok, chill.... (0.00)
Posted by Gary Kaufman on 2004-04-13, 09:14:40 (130.189.41.169)
Jimmy - When I saw your post about the Heintz-Kaufman 811A's, then saw the listing on Ebay listing WAVAC with a "humorous" buy-it-now price of $188/pair it triggered my posting. Then I saw your postin .......
287: Tubes Asylum, Glad to hear that - Seemed like too much of a coincidence (0.00)
Posted by Gary Kaufman on 2004-04-13, 07:23:11 (130.189.41.169)
Seemed like too much of a coincidence - Heintz Kaufman 811A's, mention of WAVAC and a seller named Jim.... .......
288: Tubes Asylum, If this is your auction, you're nuts! (0.00)
Posted by Gary Kaufman on 2004-04-13, 06:26:51 (130.189.41.169)
Most later Heintz-Kaufman tubes were rebranded / misslabeled stuff. I'd be especially suspicious that black based 811A's are Russian. The pic is a typical later HK box, including a Russian 6B4G label .......
289: Tube DIY Asylum, Re: Proud Papa....First DIY amp... Gary K's 6EM7... (0.00)
Posted by Gary Kaufman on 2004-04-13, 05:20:48 (130.189.41.169)
Hey, I'm impressed! Very classy looking. Don't laugh at this, but try another brand of NiMH AA's. I actually am somewhat convinced that they affect the sound. - Gary .......
290: Tube DIY Asylum, Re: Build/Sell Me an SE Amp? (0.00)
Posted by Gary Kaufman on 2004-04-07, 18:28:58 (69.163.33.243)
Vinnie - Actually only the plate leads and the transformer had anything over 425vdc on them. I had them separated by a good bit of airspace for safety! Glad to hear you're still "clippin'" ::: TOPIC .......
291: Tube DIY Asylum, Re: Build/Sell Me an SE Amp? (0.00)
Posted by Gary Kaufman on 2004-04-07, 08:48:52 (130.189.41.169)
Joe - Sorry I haven't replied to your personal email - busy week. But, here are some suggestions. First, see if you can experience the SE world locally. If you're in the NorthEast, let me know. Second .......
292: Tube DIY Asylum, Re: Sockets for 27/56 tube? (0.00)
Posted by Gary Kaufman on 2004-04-03, 08:07:12 (69.163.33.243)
Ned Carlson (www.triodeel.com) AES (www.tubesandmore.com) Angela (www.angela.com) All of them carry the current Chinese ceramic plate style 5 pin sockets. Ned has some nice Amphenol "S" mounts as well .......
293: Tube DIY Asylum, Yup! (0.00)
Posted by Gary Kaufman on 2004-04-03, 04:44:07 (69.163.33.243)
See the top right in the picture. I use the delay to short out a 1K/10W resistor after 15 seconds. The resistor is between the plate transformer and the first choke. The power supply slow starts with .......
294: Tube DIY Asylum, transmitting tube tester (0.00)
Posted by Gary Kaufman on 2004-04-02, 10:01:47 (130.189.41.169)
Anyone have a good schematic for a tester for transmitting tube types (211,845,838 etc). I've been testing using a bench supply, and watching plate current at around 500v while adjusting grid voltage. .......
295: Tube DIY Asylum, Re: Need relay advice (0.00)
Posted by Gary Kaufman on 2004-04-01, 05:11:53 (130.189.41.169)
Bryan - Look at kit CPS152 from Kitsrus http://www.electronics123.com distributes the board in the US It is a cute digital delay board with variable turn on, and instant turn off. The only problem is .......
296: Tube DIY Asylum, ESR! (0.00)
Posted by Gary Kaufman on 2004-03-31, 17:06:04 (69.163.33.243)
Bob Parker's ESR meter will spot many caps that have lost their filtering capacity thru increased ESR. It doesn't measure the actual capacitance, but provides a very useful measure of function. Very .......
297: SET Asylum, Re: Question about Tung-Sol 6550's (0.00)
Posted by Gary Kaufman on 2004-03-30, 15:38:45 (69.163.33.243)
I was once told that the holes were used for alignment of the plates during manufacturing. No idea if this is actually true! .......
298: Tube DIY Asylum, Beetlejuice, Beetlejuice.... (nt) (0.00)
Posted by Gary Kaufman on 2004-03-30, 07:29:18 (130.189.41.169)
.......
299: Tube DIY Asylum, Re: Lambda Pass Tubes (0.00)
Posted by Gary Kaufman on 2004-03-26, 09:21:00 (130.189.41.169)
David - I would suspect you can, as the pass tubes are usually in parallel with individual grid resistors. The Lambda's I've seen have only oil caps, and most power up nicely. I was looking at vario .......
300: Tube DIY Asylum, Lambda C-281M Schematic? (0.00)
Posted by Gary Kaufman on 2004-03-26, 07:11:10 (130.189.41.169)
Anyone have a copy of the schematic or manual for a Lambda C-281M power supply? This is a heavy beast, with 6 x 6W6GT's as the pass tubes and a pair of 5U4GB's. There is a schematic stuck to the side .......
301: Tube DIY Asylum, Re: Teething troubles. (0.00)
Posted by Gary Kaufman on 2004-03-26, 06:14:07 (130.189.41.169)
Steve - Check your volume potentiometer wiring. I've built the same circuit, and the gain really isn't excessive (and should be very similar to the foreplay). .......
302: Tubes Asylum, Not really... (0.00)
Posted by Gary Kaufman on 2004-03-24, 11:26:49 (130.189.41.169)
6J5 = metal 6J5GT = short tubular 6J5G = shouldered tube AES has 6J5 metal for $5.30 The GT's are $9.40 and the G's are $21.30 Admittedly that's still a lot cheaper than $80-100 / pair but the GEC's a .......
303: Tube DIY Asylum, Re: Selenium Rectifier replacement (0.00)
Posted by Gary Kaufman on 2004-03-23, 12:20:50 (130.189.41.169)
Also check the resulting bias voltage which may be a bit more negative as silicon has a lower voltage drop. In many amps you have to adjust the voltage divider slightly to bring things back in line. : .......
304: Tubes Asylum, Re: to Gary Kaufman and others about 6EM7 PP amp (0.00)
Posted by Gary Kaufman on 2004-03-23, 06:34:51 (130.189.41.169)
William - I've never used the 6EM7 in PP, however several others have. There was a recent schematic in Valve (link below) by Pete Palmer, and searching on 6EM7 and Push Pull will turn up a few more. - .......
305: Tubes Asylum, Probably is a Chinese 2A3 (0.00)
Posted by Gary Kaufman on 2004-03-18, 13:02:40 (130.189.41.169)
I've seen several "counterfeit" 45's that were actually 2A3's. Even RadioShack marketed 2A3's as 45's (I have one of the military 5930's that is overstamped with 45 in a Radio Shack box!). 45's are a .......
306: Dynaco-Doctor Forum, National GZ34 (0.00)
Posted by Gary Kaufman on 2004-03-18, 05:23:33 (130.189.41.169)
Can you post a picture of the National GZ34? My experience has been that they are either a Russian indirectly heated triode similar to a 5Z4 or a rebranded Bendix 6106. Neither will survive the curren .......
307: Tube DIY Asylum, Re: IIRC 6F3 is chinese for ECF80..... nope... (0.00)
Posted by Gary Kaufman on 2004-03-17, 14:42:17 (130.189.41.169)
Don't think so, both are similar but the pinout is scrambled between the two. The 6F3 appears to be a 9LY base, ECF80 is a 9DC .......
308: Tube DIY Asylum, Re: Great litlle psu.. (0.00)
Posted by Gary Kaufman on 2004-03-17, 13:17:20 (130.189.41.169)
Good thought, it would be easy to bypass the bridge rectifier with two jumpers, and hook the DC from a tube rectifier to the "AC input". I'll see if I can squeeze another connector onto the board. It .......
309: Tube DIY Asylum, Re: 250v Tube Regulated Power Supply - PCB design and schematic (0.00)
Posted by Gary Kaufman on 2004-03-17, 13:13:54 (130.189.41.169)
Gordon - I had considered the 6BM8 but was able to locate 6GV8's for around $0.80 each. Pretty funny when the socket costs way more than the tube! I've also seen "R6" tied to the unregulated side in s .......
310: Tube DIY Asylum, 250v Tube Regulated Power Supply - PCB design and schematic (0.00)
Posted by Gary Kaufman on 2004-03-17, 08:28:31 (130.189.41.169)
Lately I've been on a linestage kick, and it seems I start every project by designing an appropriate power supply. Most end up in the 200 - 300v range. It seemed to make more sense to develop a small .......
311: Tubes Asylum, Re: Testing a 6528A Tube (0.00)
Posted by Gary Kaufman on 2004-03-16, 13:39:49 (130.189.41.169)
Good point, in that case TV7 should work, as setting for the 6336 are published: 6.3v HY4-5062 Bias 100 C 3 36 (triode 1) 6.3v HY1-2035 Bias 100 C 3 36 (triode 2) As Triodethom noted above, GM is high .......
312: Tubes Asylum, Re: Testing a 6528A Tube (0.00)
Posted by Gary Kaufman on 2004-03-16, 11:03:35 (130.189.41.169)
The pinout is the same as 6AS7/6080 (or 6SN7 for that matter) but don't just plug it in! I don't think many commercial testers would be able to delivery 6.3v@5A filament. You could make up a jig, and .......
313: Tube DIY Asylum, Bob Danielak is probably a better person to ask! (0.00)
Posted by Gary Kaufman on 2004-03-16, 10:50:03 (130.189.41.169)
Bob Danielak is probably a better person to ask, but as far as I know the only "requirements" are using a 1626 output tube! Back in the early day's of the "Darling craze" I made a purchase of several .......
314: Tube DIY Asylum, Re: Great topic for discussion... (0.00)
Posted by Gary Kaufman on 2004-03-12, 17:19:44 (69.163.33.243)
The line filter chokes I have are Miller, rated at .600Mh. My 1958 catalog lists various values from .05 thru .6Mh with current ratings from 2 thru 30 amps! Impressively it appears that Miller is stil .......
315: Tube DIY Asylum, Re: MV rectifiers, oscillation, and RF chokes (0.00)
Posted by Gary Kaufman on 2004-03-12, 09:07:40 (130.189.41.169)
Erik - Look in older ARRL yearbooks. Lots of good info about MV rectifiers and huge power supplies. Millen, EF Johnson etc used to make small RF chokes for the filament leads. I don't know of any curr .......
316: Vintage Asylum, 6K6GT and 5Y3GT probably (0.00)
Posted by Gary Kaufman on 2004-03-09, 06:42:56 (130.189.41.169)
The tubes are likely a 6K6GT and 5Y3GT based on the other tubes in the set. I couldn't locate the R489A chassis in my copy of Rider's, but you may have luck thru some of the online vendors. Among oth .......
317: Tubes Asylum, A few more... (0.00)
Posted by Gary Kaufman on 2004-03-01, 16:41:49 (69.163.33.243)
Despite their low esteem, many tv tubes are fantastic audio performers. Others are good for regulated supplies etc. As Douglas pointed out the 6BX7, 6DN7 and 6BL7 are very good audio tubes. A few othe .......
318: Tubes Asylum, Re: Hum in 2A3 (0.00)
Posted by Gary Kaufman on 2004-02-22, 09:37:49 (69.163.33.243)
Don't worry about the 2A3 markings. If it has 4 pins and a 2A3 like plate structure it's either a 2A3 or 6A3 - pretty easy to tell apart. You may find that a good tube dealer is less expensive than Eb .......
319: Tubes Asylum, Re: Hum in 2A3 (0.00)
Posted by Gary Kaufman on 2004-02-21, 11:12:55 (69.163.33.243)
Does your amp use a hum-pot on the filament? Sometimes small adjustments can make a large difference with DHT's. Many tube testers can't put out enough current at 2.5v to test 2A3's properly. I've ne .......
320: Tube DIY Asylum, Re: Best sounding Oil Filled caps? Gary K??? (0.00)
Posted by Gary Kaufman on 2004-02-06, 17:17:11 (69.163.33.243)
Sorry I dropped out of sight. I was off in New Orleans for a week. Good Jazz, lots of Blues, great food. The Hilton unfortunately only had internet service in the public areas of the lobby - rather in .......
321: Tube DIY Asylum, Pretty long! (0.00)
Posted by Gary Kaufman on 2004-02-04, 11:45:50 (66.135.10.66)
Lifespan of oil caps is pretty long, but I'd suggest you get a good cap meter if you plan to recycle old capacitors. The Sprague series is quite nice, and the EICO 950B is very inexpensive and works .......
322: Tubes Asylum, Re: Tube ID 7189's (0.00)
Posted by Gary Kaufman on 2004-01-31, 19:29:09 (69.163.33.243)
Probably TelefunKEN, look for the diamond molded in the glass between the pins. .......
323: Tubes Asylum, Re: Fisher X-202-B (0.00)
Posted by Gary Kaufman on 2004-01-31, 19:27:48 (69.163.33.243)
The 7247/12DW7 is essentially 1/2 of a 12AX7 and 1/2 of a 12AU7 in the same bottle. I recall that EICO claimed the tube was developed at their request. It is pretty common in Eico gear, and Dynaco use .......
324: Tube DIY Asylum, Surplus Electronics in New Orleans? (0.00)
Posted by Gary Kaufman on 2004-01-30, 19:10:16 (69.163.33.243)
Any good electronic spots to hit (or antique radio etc) in the New Orleans LA area? I'll be there next week and might have a bit of free time... .......
325: Tube DIY Asylum, Johnson 211 socket (0.00)
Posted by Gary Kaufman on 2004-01-28, 09:08:19 (130.189.42.129)
I also have a pair of incorrectly marked 211 sockets. Funny thing is that they are marked correctly on one side, and not on the other. I can't recall if the top or bottom was the incorrectly marked si .......
326: Dynaco-Doctor Forum, Re: ST70 Driver Boards... (0.00)
Posted by Gary Kaufman on 2004-01-21, 18:36:40 (69.163.33.243)
Ned - Thanks for confirming. Is the documentation anywhere online - I couldn't find it on your website. .......
327: Dynaco-Doctor Forum, Re: ST70 Driver Boards... (0.00)
Posted by Gary Kaufman on 2004-01-21, 18:36:40 (69.163.33.243)
Ned - Thanks for confirming. Is the documentation anywhere online - I couldn't find it on your website. .......
328: Dynaco-Doctor Forum, ST70 Driver Boards... (0.00)
Posted by Gary Kaufman on 2004-01-20, 19:13:17 (69.163.33.243)
Ok, I'm a sucker for Dynaco stuff. I picked up a batch of 4 ST70 driver boards tonight. There was: 1) Original ST70 board 2) AVA (Van Alstine) board for the "Super 70i" 3) Wavelength Audio (1992 - Mod .......
329: Tubes Asylum, Gosh... (0.00)
Posted by Gary Kaufman on 2004-01-15, 06:24:42 (130.189.41.169)
I suppose I've gone over the top, I couldn't imagine trying to inventory my attic. Fortunately I can "usually" remember where most of the rarer stuff is. It's the common stuff I occasionally break dow .......
330: Dynaco-Doctor Forum, Re: Dynaco PS-1 and PAM-1? (0.00)
Posted by Gary Kaufman on 2004-01-03, 09:34:43 (68.169.1.132)
Randy - The problem with the AA Moniker system is that I never recognize folks! Still have the FM2-A kit proudly displayed (and the scan of the manual is on the CDROM). Many thanks for that addition t .......
331: Dynaco-Doctor Forum, Re: Dynaco PS-1 and PAM-1? (0.00)
Posted by Gary Kaufman on 2004-01-02, 18:01:20 (68.169.1.132)
I'm the guy who sells the Dynaco CDROM. The PS-1 schematic is also on line at my website for free downloading. It's a very simple circuit, troubleshooting should be trivial. I haven't looked at the PS .......
332: Dynaco-Doctor Forum, Re: ST-70 15.6 resistor replacement (0.00)
Posted by Gary Kaufman on 2004-01-02, 17:56:12 (68.169.1.132)
Just grab a pair of 29.4 and 33.2 ohm 1/4 or 1/2 watt 1% resistors and place them in parallel. These are standard 1% values stocked by Mouser etc. It comes out to 15.6 ohms at either 1/2 or 1 watt, mo .......
333: Tubes Asylum, Re: RCA 6550 (0.00)
Posted by Gary Kaufman on 2003-12-30, 13:57:37 (24.50.149.67)
Ian - I don't believe RCA ever made a 6550. They did however market 6550's and I've seen TungSol, Sylvania and GE 6550/6550A's branded RCA. Also be careful of modern "counterfeits". Although I ha .......
334: Tubes Asylum, Re: Replace 7355 with 7591XYZ? (0.00)
Posted by Gary Kaufman on 2003-12-28, 18:00:26 (24.50.149.67)
Dyou have a schematic for your amp? If you could scan and email I could help answer better. .......
335: Tube DIY Asylum, Re: Multi section cap replacement (0.00)
Posted by Gary Kaufman on 2003-12-28, 16:51:23 (24.50.149.67)
CODA - Should be an easy cap to rebuild, as has been discussed recently. I'd bet you can stuff a pair of 47uf/350v radial caps and a 470uf/63v cap inside the can nicely. Alternately replace with a 50 .......
336: Vintage Asylum, Re: Fisher FM50-B Tuner (0.00)
Posted by Gary Kaufman on 2003-12-28, 11:49:06 (24.50.149.67)
Jeff - Unfortunately, other than the simple alignment used by Dynaco FM3's I have no experience with FM tuner alignment. I do have basic instruments (scope, 5mhz function generator, HP334a distortion .......
337: Vintage Asylum, Re: Fisher FM50-B Tuner (0.00)
Posted by Gary Kaufman on 2003-12-28, 06:09:57 (24.50.149.67)
Jeff - I also suspected a cold solder joint, and hearing your experience was reassuring. I reflowed the mpx section and the output section. I also replaced all of the electrolytics under the chassis a .......
338: Tubes Asylum, Re: Replace 7355 with 7591XYZ? (0.00)
Posted by Gary Kaufman on 2003-12-26, 14:26:57 (24.50.149.67)
I'd personally go with the 7355's, if only to keep the system original. Just watch the tubes for the first hour or so - in case you have a tube that varies widely in plate current from the others. The .......
339: Vintage Asylum, no, but... (0.00)
Posted by Gary Kaufman on 2003-12-26, 06:36:18 (130.189.41.169)
I'd looked in the past, but must have botched the search. It does show up as being available! I have the Sams for the FM-50, but don't have a copy of the FM50-B version. Apparently it is a schematic o .......
340: Vintage Asylum, Fisher FM50-B Tuner (0.00)
Posted by Gary Kaufman on 2003-12-25, 18:42:51 (24.50.149.67)
I have a Fisher FM50-B that is dropping out one channel once fully warmed. As I'm starting to go thru it a schematic would really help. Anyone have the schematic they could share? Many thanks, - Gary .......
341: Tube DIY Asylum, Re: Need to find surplus transformer (0.00)
Posted by Gary Kaufman on 2003-12-24, 13:24:06 (24.50.149.67)
The part # for what you are seeking is Chicago F-65 - Gary .......
342: Tubes Asylum, Re: Triodes - Yeah, buddy! (0.00)
Posted by Gary Kaufman on 2003-12-24, 08:15:00 (130.189.41.169)
Thanks for the kind words. I'm way behind on updating the site - hopefully early next year I can do some serious typing and scanning. The 6A5 is a very nice tube, but tough to locate. I've only turned .......
343: Tube DIY Asylum, Re: Ideas for thrift store projects needed... (0.00)
Posted by Gary Kaufman on 2003-12-24, 07:42:07 (130.189.41.169)
Sadly, many of the printer bricks are internally fused - once you overload them, you can toss'em. Probably not much use for audio (at least not tube audio). .......
344: Tubes Asylum, Re: Triodes (0.00)
Posted by Gary Kaufman on 2003-12-23, 15:41:32 (24.50.149.67)
JJ - You can eek out 2 watts or so from most of them, and 5-6 watts using the 6BX7 as PP/Parallel. They put you well into the range you'll get from a 45 or 2A3 amp and substantially lower cost. I've p .......
345: Tubes Asylum, Re: Replace 7355 with 7591XYZ? (0.00)
Posted by Gary Kaufman on 2003-12-23, 10:20:08 (130.189.41.169)
It should work as long as the residual metal doesn't make any contact with the socket. Personally I'd just use a small terminal strip and relocate any wiring from pin 4. I'd hate to see someone retube .......
346: Tubes Asylum, Re: Triodes (0.00)
Posted by Gary Kaufman on 2003-12-23, 10:17:03 (130.189.41.169)
TCr - Although not in current production, the family of "TV Triodes" are inexpensive and very good sonically. The 6BX7, 6BL7, 6DN7, 6EM7, 6S4 etc are all worth exploring. .......
347: Tube DIY Asylum, Re: Advice on Potentiometer Replacement (Scott 233) (0.00)
Posted by Gary Kaufman on 2003-12-23, 07:22:04 (130.189.41.169)
Is the old potentiometer totally dead, or just scratchy? Many times if the potentiometer is just scratchy a good squirt of contact cleaner will work. If that doesn't help look at the coupling cap lea .......
348: Tube DIY Asylum, Re: Diego Nardi's linestage in 'Sound Practices' #14 (0.00)
Posted by Gary Kaufman on 2003-12-23, 03:36:42 (24.50.149.67)
Andy - Found it in issue #15 - 350vdc B+ with the heater dividers as you mentioned. Thanks! .......
349: Tubes Asylum, Re: Replace 7355 with 7591XYZ? (0.00)
Posted by Gary Kaufman on 2003-12-22, 08:55:29 (24.50.149.67)
Sounds like they have worn gettering, but visual appearance doesn't really tell you the condition of the tube. While it sounds like new output tubes are in order, remember to check coupling caps, byp .......
350: Tubes Asylum, Re: Replace 7355 with 7591XYZ? (0.00)
Posted by Gary Kaufman on 2003-12-22, 07:28:34 (24.50.149.67)
Ches - Just make sure that pin 4 isn't used as a tie point in your amp. On the 7591xyz it is a second connection to the screen. On the 7355 it is unused. Occasionally old amps make use of these unused .......
351: Tube DIY Asylum, You can also rebuild them... (0.00)
Posted by Gary Kaufman on 2003-12-22, 07:18:29 (24.50.149.67)
You can also cut open and rebuild the original can cap. With a 2 section cap it is pretty easy. A pair of 47uf/450v caps should fit nicely inside. This is usually a far less expensive option. - Gary : .......
352: Vintage Asylum, Re: You have mail (0.00)
Posted by Gary Kaufman on 2003-12-18, 08:04:28 (130.189.41.169)
Many thanks! Amplifier section looks similar. .......
353: Tube DIY Asylum, Re: Diego Nardi's linestage in 'Sound Practices' #14 (0.00)
Posted by Gary Kaufman on 2003-12-18, 03:22:59 (24.50.149.67)
Andy - As I recall it was very nice looking, but I missed listening to it. I think I spent too much time chatting in the hallway... I peeked at the article last nite, but couldn't easily figure out wh .......
354: Tube DIY Asylum, Re: Diego Nardi's linestage in 'Sound Practices' #14 (0.00)
Posted by Gary Kaufman on 2003-12-17, 11:28:55 (130.189.41.169)
Happy to send you a copy, but you'll have to provide an email address or accept mail thru AA. John E. Brought a nice version of the "Igot Nomoney" linestage to a local meet recently, pictured on the l .......
355: Tube DIY Asylum, Power Supply? (0.00)
Posted by Gary Kaufman on 2003-12-17, 08:18:20 (130.189.41.169)
Looks like a power supply to me - From left to right, I'd guess you have a Power transformer, Filter cap and rectifier, two chokes and 4 voltage regulator tubes (like OC3's). .......
356: Vintage Asylum, Re: Kenwood KW-60 (0.00)
Posted by Gary Kaufman on 2003-12-16, 18:29:27 (24.50.149.67)
John - I wouldn't mind seeing the schematic, I'd bet they are similar. This receiver uses a pair of 6CA4's for B+. If it's easy to scan at a good resolution and Email let me know, or I can send you po .......
357: Tube DIY Asylum, Re: Subsitute for 6D22 (6CH3 or 6CJ3) (0.00)
Posted by Gary Kaufman on 2003-12-16, 18:21:06 (24.50.149.67)
Novar sockets have smaller pin diameters than Magnovol. Both are available thru many vendors. If you have trouble locating them let me know as I have a good supply. If you really want a tube like the .......
358: Vintage Asylum, Kenwood KW-60 (0.00)
Posted by Gary Kaufman on 2003-12-16, 16:20:13 (24.50.149.67)
I grabbed a Kenwood KW-60 receiver from a record shop tonight while waiting for Japanese take-out food (seem'd appropriate). Typical PP 6BQ5 amp section and nice looking output transformers. Anyone .......
359: Tubes Asylum, Re: Silly bias question (0.00)
Posted by Gary Kaufman on 2003-12-13, 12:00:51 (24.50.149.67)
Not so silly - What you really want to know is the "bias current" thru the tube. As a way of assessing this current you can measure the voltage this current produces across a known resistor. For examp .......
360: Vintage Asylum, Re: Smaller Advent (0.00)
Posted by Gary Kaufman on 2003-12-05, 13:47:34 (130.189.41.169)
I believe I still have a pair of tweeters pulled from small advents. I recall that they are also orange however. .......
361: Vintage Asylum, Re: Heathkit W2M (0.00)
Posted by Gary Kaufman on 2003-12-05, 13:44:18 (130.189.41.169)
The Heathkit W2M and W3M are identical except for the output transformer. I have only a single W2M, so haven't listened in stereo to that unit. I have many W3Ms (anyone in the reverse situation - I'd .......
362: Tube DIY Asylum, Re: New Readings (0.00)
Posted by Gary Kaufman on 2003-11-30, 20:18:05 (24.50.149.67)
Alfredo - I'd suggest you disconnect the chassis ground lead from the AC cord. It can lead to strange ground loops and other noise problems. If you really want to connect it run it thru a 10 ohm res .......
363: Tube DIY Asylum, Re: Help With Low Cathode Voltage (Tube Crossover) (0.00)
Posted by Gary Kaufman on 2003-11-30, 18:01:12 (24.50.149.67)
Alfredo - It's a bit tough to tell from the pic's, but I have some ideas... I see the Red/Yellow (B+ Centertap) going to the OD3 but I don't see it going on to the crossover board. Is the OD3 glowing? .......
364: Tubes Asylum, Re: Rectifier - 5Y3GT (0.00)
Posted by Gary Kaufman on 2003-11-30, 14:10:19 (24.50.149.67)
Short answer is yes. GT denotes a T9 bulb WGTB is ruggedized and with additional testing parameters. The only 5Y3's that are electrically different are the 6087 and 6106 varieties which are indirect .......
365: Tubes Asylum, Re: Where do my Pro/Comm tubes come from?? (0.00)
Posted by Gary Kaufman on 2003-11-13, 13:29:41 (130.189.41.169)
Procomm can be anything, but most of their 12AX7's I've seen are EI. I purchased a case of 100 EI 12AX7's about a year ago and ran them thru a curve tracer About 50% were pretty useless, and only arou .......
366: Tube DIY Asylum, Re: Just finished a 6EM7 amp! (0.00)
Posted by Gary Kaufman on 2003-11-13, 13:18:16 (130.189.41.169)
Mike - Glad you like the amp, and thanks for the kind words. I've been away from the Asylum for a bit, so may have missed earlier postings. This amp was a try at simplicity and low cost - and one that .......
367: Tube DIY Asylum, Re: class A all the way... (0.00)
Posted by Gary Kaufman on 2003-11-07, 10:57:03 (130.189.41.169)
My 46 amp started out as Gordon Rankin's Bugle 45 design. I've retained the driver stage (5751 srpp). I add a 1K resistor after the 330v B+ (a combined supply for both channels) to drop it to 285v. Th .......
368: Tubes Asylum, Re: A 7355 tube can replace a 7591 ? (0.00)
Posted by Gary Kaufman on 2003-11-07, 10:36:11 (130.189.41.169)
A 7355 has essentially the same pinout as a 7591, but is more akin to a 6L6 electrically. Although it has been used as a 7591 substitute in the past it requires changing the bias circuitry and really .......
369: Tubes Asylum, Re: How Good Sounding Is the Dynaco FM-3? Opinions? (0.00)
Posted by Gary Kaufman on 2003-08-08, 19:09:27 (67.22.194.28)
As Bill points out, the FM3 can be very nice sounding as long as you are in an area with reasonable signal strength and fairly well spaced stations. IMHO it doesn't compare to any of the nicer Fisher .......
370: Tube DIY Asylum, Re: Testing 6C33's on TV-7D/U (0.00)
Posted by Gary Kaufman on 2003-08-08, 18:57:25 (67.22.194.28)
Sorry, but no easy way to test... Besides the obvious lack of a septar socket without an adapter, the TV7 won't come close to providing enough filament current. I did try and match up a batch of 6C33' .......
371: Tube DIY Asylum, Re: 394A thyratron as a rectifier questions... (0.00)
Posted by Gary Kaufman on 2003-08-08, 15:53:39 (67.22.194.28)
Pete - The person to speak with about 394A's is Dave Slagle, but I can pass along a bit of his advice. I've been considering them as well for a future project. I'm the voltage drop is 15-20v iirc. App .......
372: High Efficiency Speaker Asylum, Re: Seeburg Woofers ?? Altec ?? (0.00)
Posted by Gary Kaufman on 2003-07-28, 14:07:12 (67.22.194.28)
Thanks to all for the help! .......
373: High Efficiency Speaker Asylum, Seeburg Woofers ?? Altec ?? (0.00)
Posted by Gary Kaufman on 2003-07-27, 08:48:03 (67.22.192.82)
A large Seeburg cabinet followed me home yesterday. Cabinet was huge and in poor shape, but it contained an Altec 811 horn, 806A driver, and a pair of woofers. The woofers are 15" baskets, and look li .......
374: Vintage Asylum, Philips AH7861 (0.00)
Posted by Gary Kaufman on 2003-07-24, 14:13:02 (68.169.16.110)
Well, my town added a new "swap shed" at the "transfer station" and after a few weeks of old lamps and printers I finally turned up something audio. A rather nice condition Philips AH7861 receiver. Se .......
375: Tube DIY Asylum, Re: 6EM7 amp designs (0.00)
Posted by Gary Kaufman on 2003-07-22, 17:19:41 (68.169.16.110)
See my website for a DC coupled design that works nicely. - Gary .......
376: Tubes Asylum, On the money! (0.00)
Posted by Gary Kaufman on 2003-07-21, 09:49:42 (68.169.16.110)
Steve - I strongly agree. I'd add that a life test on a signal tube is of little use imho. Has anyone ever seen any real documentation that it in anyway correlates with remaining useful life in a sig .......
377: Tube DIY Asylum, Re: Looking for a GOOD 211 / VT4-C Schematic (0.00)
Posted by Gary Kaufman on 2003-07-19, 05:29:08 (68.169.16.110)
Acutally my power supply is very different than the one on PAE's site. I use individual AC transformers for each 211 filament, the 866jr and the 6C45 filament. The large Acro TP-550 provides 825-290-0 .......
378: Tube DIY Asylum, Re: Looking for a GOOD 211 / VT4-C Schematic (0.00)
Posted by Gary Kaufman on 2003-07-18, 08:14:38 (68.169.16.110)
Don't believe everything you read about high B+ and transmitting triodes. Many folks have been using 845's at low B+ with good results. I played around with 211's and finally settled on a B+ of 825v, .......
379: Tube DIY Asylum, Re: Heath IP-32, just rebuilt (0.00)
Posted by Gary Kaufman on 2003-07-17, 06:05:23 (68.169.16.110)
Kevin - Why bother to convert to 6AR6's? The 6L6GC is easy to locate and inexpensive. Plus it's a good place to hide those flea market pulls that test good but look really ugly... Even the Russian stu .......
380: Vintage Asylum, Re: HF-81 AC socket (0.00)
Posted by Gary Kaufman on 2003-07-16, 18:43:36 (68.169.16.110)
Barrie - The HF81 should have a fuse, 2 wire ac cord thru a grommet, and a 2 wire ac plug on the back right of the amp. If not, someone has changed something. To work well the HF81 will need filter ca .......
381: Tube DIY Asylum, Re: Heath IP-32, just rebuilt (0.00)
Posted by Gary Kaufman on 2003-07-16, 17:36:56 (68.169.16.110)
Kevin - The IP-32 is a great bench supply, but I'm not sure you'll like it for long term use driving a preamp. It gets pretty warm with the dual 6L6GC's as pass tubes. They are nice once recapped. If .......
382: Tubes Asylum, Re: Hickok 600A Tube Tester (0.00)
Posted by Gary Kaufman on 2003-07-13, 18:29:55 (68.169.16.110)
I'd bet the 5V4G would throw off calibration. I can tell you that I've seen Hickok's with 80's sub'd for 83's and it doesn't work well. The 5V4G is certainly closer, but why bother. Remove the 5V4G, a .......
383: Tubes Asylum, Re: Svetlana 5U4's? (0.00)
Posted by Gary Kaufman on 2003-07-11, 21:48:47 (68.169.16.110)
Good old american 5U4GB's are common and relatively inexpensive. They work well (and last a long time) in the Mc30. IMHO there isn't squat difference between brands of NOS 5U4GB's. A pair shouldn't s .......
384: Tube DIY Asylum, Re: RKR-72 tube (0.00)
Posted by Gary Kaufman on 2003-07-10, 06:14:05 (68.169.16.110)
The RKR-72 is a radar vacuum rectifier, filament 2.5v/3A, piv is 22kv, 20ma max The 3B24 is similar (but has a dual 2.5/5v filament). .......
385: Tubes Asylum, Re: Anyone have specs on Stancor PT-8311 transformer. (0.00)
Posted by Gary Kaufman on 2003-07-02, 16:22:55 (68.169.16.110)
Gosh, hit return and noticed your posting as well. I guess we were typing at the same time. Very nice catalog, thanks for the link. BTW, if you want some "pure death" I just picked up a pair of Chica .......
386: Tubes Asylum, Yup... (0.00)
Posted by Gary Kaufman on 2003-07-02, 16:12:29 (68.169.16.110)
PT8311 1200-0-1200 AC secondary 1000 D.C. Volts "D.C. output rated at load terminals of single-section, reactor-input filter with full-wave mercury-vapor rectification. Primaries for 117 volts, 60 cyc .......
387: Tube DIY Asylum, Re: Top ten peve's of amplifier design. (0.00)
Posted by Gary Kaufman on 2003-07-02, 16:02:17 (68.169.16.110)
Gordon - A question about your opinion of carbon plates. Most 211/845 amps involve several of your other dislikes (multiple driver stages, banks of capacitors, IT coupling, dc coupled driver to outpu .......
388: Tube DIY Asylum, cap! (0.00)
Posted by Gary Kaufman on 2003-07-02, 05:53:19 (68.169.16.110)
Exactly right, I miss-typed, sorry for the confusion. Even if the power supply delivers the correct voltage choke loaded, a small (like .22uf) cap at the input will greatly reduce the buzzing without .......
389: Tube DIY Asylum, Re: No load... (0.00)
Posted by Gary Kaufman on 2003-07-01, 19:53:15 (68.169.16.110)
If you model with a 5V4GA you'll be pretty close on voltages as the voltage drop should be very similar. That said, Douglas is correct. Even with a modest load I bet you'll end up with around 475vdc f .......
390: Tubes Asylum, Re: 407a tubes (0.00)
Posted by Gary Kaufman on 2003-06-26, 19:58:52 (68.169.16.110)
Gosh, hopefully not too much. 407A's are pretty much an orphan tube, and not particularly rare. .......
391: Tubes Asylum, Re: 407a tubes (0.00)
Posted by Gary Kaufman on 2003-06-24, 16:15:20 (68.169.16.110)
Well, sorry to tell you... No explosion, but no music either. The 407A is a direct replacement, but has a 20/40v filament. It won't do squat in a 5670 socket. The WE tube you'll need is a 2C51 or 396A .......
392: Tubes Asylum, Re: TV damper diode recommendations (0.00)
Posted by Gary Kaufman on 2003-06-24, 16:11:58 (68.169.16.110)
There are plenty of Octal socket 6.3v damper diodes. 6AU4 is just one of many that would meet your needs. Then again, what sort of a preamp needs 200ma??? Most linestages are For suppliers, there are .......
393: Tube DIY Asylum, Re: Another question for Gary (0.00)
Posted by Gary Kaufman on 2003-06-24, 16:07:12 (68.169.16.110)
Francois - Good question, and one I can't really answer. I built the 6EM7 amp long after the DC-Darling and after a modest audition at home I dragged it to work. It's been there for over a year now. I .......
394: Tube DIY Asylum, Re: Source for 6EM7s (0.00)
Posted by Gary Kaufman on 2003-06-24, 15:43:03 (68.169.16.110)
Lots of other vendors... Both of these 2 have them @ $6 each. You could also look for 10EM7 or 13/15EM7's and run the filament off of DC. Dick Bergeron at http://members.aol.com/etetubes/ Jim Cross a .......
395: Vintage Asylum, Dyna FM-2A (0.00)
Posted by Gary Kaufman on 2003-06-24, 06:03:18 (68.169.16.110)
I have the same unbuilt kit (which even has the tubes...). They were pretty cool, but reportedly had huge heat problems and were unreliable. I've never seen one in the tuner (and don't have the heart .......
396: Tube DIY Asylum, Re: question (0.00)
Posted by Gary Kaufman on 2003-06-23, 21:02:02 (68.169.16.110)
Anand - Those were the "target" operating points per the curves. The second section is elevated to "line up" with the first section. The actual voltages are on the schematic. It took a bit of playin .......
397: Tube DIY Asylum, Gosh <blushing> Thanks! nt (0.00)
Posted by Gary Kaufman on 2003-06-23, 19:34:28 (68.169.16.110)
.......
398: Tube DIY Asylum, 6EM7! (0.00)
Posted by Gary Kaufman on 2003-06-23, 17:14:58 (68.169.16.110)
Take a peek at this 6EM7 design, which you should be able to build for I still haven't written up the power supply design, largely because I used whatever was lying around (hence the separate chokes o .......
399: Tubes Asylum, More sad pics... (0.00)
Posted by Gary Kaufman on 2003-06-19, 18:28:27 (68.169.16.110)
Wonder if the RCA's are Black plates? .......
400: Tubes Asylum, Re: How do I tell the difference between a PAS 3 and PAS 3X? (0.00)
Posted by Gary Kaufman on 2003-06-19, 18:18:30 (68.169.16.110)
The differences between the PAS 2/3 and 2X/3X are small, and an update kit was available at one time thru Dynaco. Basically the 2 was the old style front, the 3 the later aluminum style. The "X" adds: .......
401: Tube DIY Asylum, Re: tubes- 1626 (0.00)
Posted by Gary Kaufman on 2003-06-19, 14:02:22 (68.169.16.110)
Thanks for the kind words! I was also impressed at how well the DC-Darling and Lowther's could fill up a relative large room. Thiamlin - Bob Danielak's "DC-Darling" is one of the best soundling flea .......
402: Tubes Asylum, Re: Electrolytic capacitors life ex (0.00)
Posted by Gary Kaufman on 2003-06-17, 16:34:26 (68.168.50.84)
Alex - I'm hardly an engineer! Look at Bob Parker's site - there is a great explanation of ESR, and the kit is very inexpensive (and fun to build). .......
403: Vintage Asylum, Re: Heathkit W-4am ??? (0.00)
Posted by Gary Kaufman on 2003-06-17, 13:03:05 (68.168.50.84)
The W4 can be very nice sounding, but please don't just plug it in! I don't think I've ever seen a Heathkit W1 thru W5 that had good filter caps or was nicely constructed. Remember that these heathkit .......
404: Tubes Asylum, Re: Electrolytic capacitors life expect (0.00)
Posted by Gary Kaufman on 2003-06-17, 12:57:30 (68.168.50.84)
You'd more likely get a hum, not a hiss if the filter caps are going. I'd bet the caps are fine, but there are good ways to assess them them if you have the equipment. What you need to measure is ESR .......
405: Tubes Asylum, Re: Here are the 2 photos (0.00)
Posted by Gary Kaufman on 2003-06-02, 12:07:04 (68.168.50.84)
If it has mercury inside, I'd bet on an early 816 Otherwise, probably a 2X2 .......
406: Tube DIY Asylum, Re: Do I need to shield a power umbilical? (0.00)
Posted by Gary Kaufman on 2003-06-01, 13:14:15 (68.168.50.84)
Giles - I've built the same circuit - try shields on the 12AX7's. Fix'd the problem for me. Heathkit used umbilical cords for power on the early Williamson series (WA1 thru W3) as well as for the prea .......
407: Tube DIY Asylum, BTW... (0.00)
Posted by Gary Kaufman on 2003-04-02, 14:18:38 (68.169.16.121)
BTW, don't use the 83 for a donor tube for the base (mercury risk). Thanks to Carter for pointing this out! .......
408: Tube DIY Asylum, One more thought... (0.00)
Posted by Gary Kaufman on 2003-04-02, 10:42:33 (130.189.41.169)
I should add that the 83 should really be choke loaded only. If you really need the voltage boost of a cap loaded supply consider substituting an 83V (essentially a 4 pin equivalent of a 5V4) which sh .......
409: Tube DIY Asylum, Re: My 83 flashed over and now all hell is breaking lose (0.00)
Posted by Gary Kaufman on 2003-04-02, 10:32:06 (130.189.41.169)
Rodney - MV rectifiers are a royal pain , and flashovers can be fun - you should see what a pair of 866's at 1kv look like! I'm a bit confused by a higher B+, damaging a capacitor or transformer wo .......
410: Tubes Asylum, Re: in defense of the 7199's... (0.00)
Posted by Gary Kaufman on 2003-04-01, 19:18:45 (68.169.16.121)
Actually the ST70 stresses the heater cathode insulation in the 7199 and can prematurely cause failure. A simple voltage divider to raise the filament voltage to around +75vdc will increase the 7199 l .......
411: Tube DIY Asylum, Thanks <nt> (0.00)
Posted by Gary Kaufman on 2003-03-30, 17:04:23 (68.169.16.121)
Thanks! .......
412: Tube DIY Asylum, Re: Seem to be settling a little (0.00)
Posted by Gary Kaufman on 2003-03-30, 14:51:46 (68.169.16.121)
The flickering at low current draw is common. If the different glow pattern (one up, one down) bothers you reverse the filament leads on one of the rectifiers. I don't know why, but the polarity of th .......
413: Tubes Asylum, Re: Are there really that few 12AX7 out there ? (0.00)
Posted by Gary Kaufman on 2003-03-30, 11:15:35 (68.169.16.121)
Gosh, the 12AX7 probably has a better chance of staying in production than about any other tube. I wouldn't worry about any shortage in our lifetime! .......
414: Tube DIY Asylum, Re: dynaco caps (0.00)
Posted by Gary Kaufman on 2003-03-30, 05:42:30 (68.169.16.121)
Rajiv - You can put two caps in series to increase the voltage rating. Many amps did this, look at the Heathkit WM series for example. I'd suggest a pair of resistors across the caps to balance the le .......
415: Tubes Asylum, Re: Dynaco SCA 35 headphone jack (0.00)
Posted by Gary Kaufman on 2003-03-29, 09:20:25 (68.169.16.121)
The official info is on page 6 of the assembly manual. It involves a 100 or 47 ohm 1 watt resistor. Email me if you'd like a copy of the page. Either a 1.3mb pdf by email or send me a sase ::: TOPIC:: .......
416: Vintage Asylum, Re: Replacement Circuit Boards (0.00)
Posted by Gary Kaufman on 2003-03-26, 12:31:31 (130.189.41.169)
I've used www.expresspcb.com many times. They provide a cute cad program and make a good quality board. Olimex (http://www.olimex.com/pcb/) also has a good reputation for very inexpensive work, but .......
417: Tubes Asylum, Re: Help! Using tube tester for first time and have questions... (0.00)
Posted by Gary Kaufman on 2003-03-26, 08:55:30 (130.189.41.169)
I'm not specifically familiar with the EMC tester, but suspect it is a garden variety emissions tester. 6550 setting will work fine for 6550A, the "A" has increased rating for plate dissipation. ECC88 .......
418: Tubes Asylum, Well... (0.00)
Posted by Gary Kaufman on 2003-03-25, 14:27:06 (130.189.65.126)
Ok, so here's another opinion. Please take with the appropriate dose of NaCl. The ST70 bias' the EL34's by measuring voltage across a 15.6 ohm resistor, so that measuring 1.56 volts is the equivalent .......
419: Tube DIY Asylum, Re: The "One switch" dilema... (0.00)
Posted by Gary Kaufman on 2003-03-25, 13:09:19 (130.189.65.126)
Artn - 46's are easy to locate, and fairly inexpensive even as NOS. I've never tried 59's. Finding matched quads of 46's shouldn't be difficult. Globe 46's are rather uncommon. Sonically the ST's ar .......
420: SET Asylum, Re: 2A3 amp question (0.00)
Posted by Gary Kaufman on 2003-03-25, 09:58:09 (130.189.65.126)
The confusion is that there are both the original 1930's single plate type and the current Sovtek single plate type. The original single plate (1930's) tube was a very complex design with a "harp" of .......
421: Tube DIY Asylum, Re: The "One switch" dilema... (0.00)
Posted by Gary Kaufman on 2003-03-25, 09:39:43 (130.189.65.126)
AN - Thanks for the kind words. I'm way behind on the website, and have several good projects to post eventually. My 46 amp started out as Gordon Rankin's Bugle 45 design. I've retained the driver sta .......
422: Tube DIY Asylum, Re: Transformer Question (0.00)
Posted by Gary Kaufman on 2003-03-24, 09:41:07 (68.169.16.121)
A full wave, choke loaded input power supply will give you 1.54 x the secondary current rating, or the 300ma you need out of either transformer. It may also buzz like crazy with that sort of current d .......
423: Tube DIY Asylum, Re: The "One switch" dilema... (0.00)
Posted by Gary Kaufman on 2003-03-24, 09:31:59 (68.169.16.121)
Douglas - kitsrus kit # 152 (http://www.kitsrus.com/kits.html#k152) is a small digital delay board. Quite inexpensive and adjustable for a wide range of delay periods. Runs off of 12vdc, but I can tel .......
424: Tubes Asylum, Re: 310B (0.00)
Posted by Gary Kaufman on 2003-03-23, 07:23:09 (68.169.16.121)
The 310B should substitute for a 310A easily. It is a lower hum version, and has a slightly lower u (1200 vs 1350). Except for the filament voltage, other good substitutes include the 6C6 (6.3v) and 3 .......
425: Tubes Asylum, Re: Dynaco ST-70 Power Transformer (0.00)
Posted by Gary Kaufman on 2003-03-23, 07:19:40 (68.169.16.121)
Paul - The original PA060 transformer had a waxy/tar coating and often has a "drippy" appearance. While it is a cosmetic issue, functionally they are fine. IMHO they are often less prone to buzzing th .......
426: Tube DIY Asylum, Re: Gary Kaufman more 407A questions... (0.00)
Posted by Gary Kaufman on 2003-03-23, 07:15:31 (68.169.16.121)
I used a 100K potentiometer in front of the input cap. The inexpensive RS part works nicely, I have a link to the part# higher up on the same web page. 408A's are essentially a 6AK5 like the WE403B wi .......
427: Tube DIY Asylum, Re: WE407A Preamp... (0.00)
Posted by Gary Kaufman on 2003-03-21, 11:10:45 (68.169.16.121)
Well, it's still my favorite linestage of the several dozen I've built or breadboarded. I think the 407A remains a true bargain in the WE tube lineup. I'm currently using it to drive a 6C45/211 single .......
428: Tube DIY Asylum, Re: Help!!..Thordarson PT Info needed!! (0.00)
Posted by Gary Kaufman on 2003-03-21, 10:47:16 (68.169.16.121)
Runn3R - The 22R07 is rated at: Primary 117v 50/60 cps Secondaries: 350-0-350 @ 200ma 5v rectifier at 3A 6.3v filament at 6A My experience is the the thordarson power transformers are very nicely made .......
429: Tube DIY Asylum, Re: 47 (0.00)
Posted by Gary Kaufman on 2003-03-17, 10:11:22 (130.189.41.169)
I played with pseudotriode 47's for a while, but was disappointed. I hooked them up G2 to Plate, pins 2 & 4 tied. As far as I can recall, the best operating point I found was 5K load, 285vdc B+, 500 o .......
430: Tube DIY Asylum, Re: scruff >>whining is fine: just that history of RCA is no better. Longevity however is les (0.00)
Posted by Gary Kaufman on 2003-03-15, 11:58:29 (68.169.16.121)
Ironically RCA marketed the same tubes under their label as well. I have a good handful of RCA/Yugoslavian tubes that are identical in construction to the current EI. I picked up a case of current pro .......
431: Tubes Asylum, Re: How can this be? (0.00)
Posted by Gary Kaufman on 2003-03-13, 07:21:45 (130.189.41.169)
These are late IEC boxes. Towards the end of the "classic tube era" lots of junque got boxed by various manufacturers. They look like Toshiba 6L6GC's from the picture. .......
432: Tube DIY Asylum, Re: anyone know Cg-p for type 46? = 10 pF (0.00)
Posted by Gary Kaufman on 2003-03-13, 06:19:43 (130.189.41.169)
Might be interesting to remeasure with G1 and G2 connected together (Class B hookup) and G2 connected to plate (Class A hookup). I would guess that Shane is interested in driving the 46 in Class A mo .......
433: Tube DIY Asylum, 6GK6 side note... (0.00)
Posted by Gary Kaufman on 2003-03-12, 09:04:23 (130.189.41.169)
As a side note, the 6GK6 is a great "sleeper tube". Essentially a 6BQ5 with a slightly scrambled pinout. It is almost trivial to modify most amps to take them with a simple re-pinning of the socket. T .......
434: Tubes Asylum, Re: Can a TV-7 test 6GF7? (0.00)
Posted by Gary Kaufman on 2003-03-09, 09:17:18 (68.168.40.176)
It can if you build an adapter. The 6GF7 is essentially a Novar (9 pin compactron) version of the 6EM7. Just wire up a Novar --> octal adapter and test as a 6EM7. .......
435: Tube DIY Asylum, Re: Been there! (0.00)
Posted by Gary Kaufman on 2003-03-06, 17:27:04 (68.168.40.176)
I have three pairs of the Chinese 211's. One is "unbranded" which I purchased a few years ago. The last two pairs are branded Penta, quite inexpensive thru Ebay. All seem identical, although the Penta .......
436: Tube DIY Asylum, Re: Been there! (0.00)
Posted by Gary Kaufman on 2003-03-05, 06:56:25 (64.0.157.4)
Stefan - Been there as well. Better iron will make a big difference particularly in the bass. The Hammond 125ESE's are surprisingly good for the price, but the limitations are real. Look into the off .......
437: Vintage Asylum, Re: help identifying and old tube amp (0.00)
Posted by Gary Kaufman on 2003-03-04, 08:27:19 (64.0.157.4)
Based on the private labeled tubes, this is most likely an Executone system. They made primarily telephone, office PA systems iirc. Most likely of limited fidelity, but I'd give it a listen... ::: TOP .......
438: Tubes Asylum, Re: Any Western Electric 301-A's out there? (0.00)
Posted by Gary Kaufman on 2003-03-04, 08:12:54 (64.0.157.4)
You could always slum it and use an 83 like the rest of us... >grin Good luck Ed, tough tube to locate .......
439: Tube DIY Asylum, Re: B+ time delay (0.00)
Posted by Gary Kaufman on 2003-03-03, 06:09:58 (64.0.157.4)
Best to switch the transformer primary if possible. Use a separate filament transformer for the tubes you need to "preheat", then switch on the B+ transformer after an appropriate delay. If you're dea .......
440: Tube DIY Asylum, Re: Darling amp distortion (0.00)
Posted by Gary Kaufman on 2003-02-25, 19:28:09 (68.168.40.176)
Stefan - Which version did you build? It should be very nice sounding. Obviously it clips easily - but within the power limits is a very sweet sounding amp. A few thoughts... Did you remember that th .......
441: Tube DIY Asylum, Re: Mercurry rectifiers (0.00)
Posted by Gary Kaufman on 2003-02-25, 12:12:45 (130.189.65.126)
Glow seems very dependent on current draw. With 866's I find unless you draw 100ma+ the glow can be erratic. Also some bulbs seem to have more mercury inside than others. I have a few older tubes that .......
442: Tube DIY Asylum, Re: Filtering Cap Value Question??? (0.00)
Posted by Gary Kaufman on 2003-02-20, 10:18:55 (130.189.41.169)
BK - Download a copy of duncan amps power supply design tool (free). It's a wonderful program. http://www.duncanamps.com You can simulate the power supply design you have in mind and try various optio .......
443: Tubes Asylum, Re: 6AS7 Equivalent? (0.00)
Posted by Gary Kaufman on 2003-02-17, 15:44:42 (68.168.40.176)
Simon - Equivalent is a 6080, but I'd make sure the TT1 can supply the 2.5A (at 6.3v) filament draw. The rest is just my brainstorming, as I haven't owned a TT1... Pinout is the same as a 6SN7, so you .......
444: SET Asylum, Re: Magne quest TFA204 S.E OPT (0.00)
Posted by Gary Kaufman on 2003-02-16, 17:34:21 (68.168.40.176)
The TFA204 is a very sweet transformer, and beautifully made. They have a truly lush midrange and crisp clean high end. My only thought is that the DS-025 is only a few $$ more and has a bit more sol .......
445: Tube DIY Asylum, Re: How about the 6A5G? (0.00)
Posted by Gary Kaufman on 2003-02-16, 11:16:17 (68.168.40.176)
Very nice tube, very little hum because of the cathode arrangement. Bad news is that they are rather scarce, and you may have real trouble finding more. OTOH, lots of 2A3 types to choose from and seve .......
446: Tube DIY Asylum, Re: P.S. re: 3C24 op points (0.00)
Posted by Gary Kaufman on 2003-02-13, 07:15:22 (130.189.41.169)
Jim - Thanks for the suggested op point, I'll have to give it a try. Did you find a source for the Eimac HR-1/HR-2 heatsinks for the pins? I've only turned up two thus far, and need two more! Also, .......
447: Tubes Asylum, Re: 6CK4 versus 2A3 in Push Pull application (0.00)
Posted by Gary Kaufman on 2003-02-13, 07:09:49 (130.189.41.169)
What's the problem with a DHT? A simple hum pot with ac heating will get you quiet enough - even on really efficient speakers. I'm running 211's with 10v filaments on ac, and the hum is very minimal. .......
448: Tubes Asylum, Current Shuguang Tubes? (0.00)
Posted by Gary Kaufman on 2003-02-12, 15:16:13 (130.189.41.169)
I ran into the Shuguang website at http://www.shuguangtubes.com and http://www.shuguangtubes.com/dzg.htm and was pleased to see them list several tubes that I wasn't aware were still in production. Do .......
449: Tubes Asylum, Re: 6em7 SPUD (0.00)
Posted by Gary Kaufman on 2003-02-12, 14:53:40 (130.189.41.169)
Ejam - I have a small PC board I've made up with the 6EM7 driver circuit that is fairly flexible. You can see the board in the bottom view of the 826 amp on my website. I wired it up the other nite us .......
450: Tube DIY Asylum, Re: playing with driver tubes in my 75TL amp (0.00)
Posted by Gary Kaufman on 2003-02-11, 20:12:31 (68.168.40.176)
Josh - Can you give me an idea of what you used as operating points for the 3C24? I keep playing with this tube (it's beautiful looking!) but I haven't figured out any reasonable operating points as e .......
451: Tubes Asylum, Re: Sockets (0.00)
Posted by Gary Kaufman on 2003-02-11, 19:34:34 (68.168.40.176)
Which tube are you asking about? The 6EW7 is a standard 9 pin minature socket, although the tube is often in a larger bottle. I believe the correct term is a "9-T9". The Sylvania 6EW7's I've seen are .......
452: Tubes Asylum, Re: 6em7 SPUD (0.00)
Posted by Gary Kaufman on 2003-02-11, 19:29:14 (68.168.40.176)
Ejam - The 6EM7 power supply uses a 560vct transformer into a 5V4G into a 40uf cap. I then used separate 12H/360 ohm chokes into separate 50uf caps for each channel. Honestly, most values are based on .......
453: Tubes Asylum, Re: That is the schematic I wanted to put a 6EW7 in... (0.00)
Posted by Gary Kaufman on 2003-02-11, 13:02:41 (130.189.65.126)
There are a handful of dual triodes that are super, 6BX7, 6BL7, 6DN7, 6DR7 just to name a few others. All are inexpensive and fun. Just stick to low voltage, higher current operating points. I bet the .......
454: Tubes Asylum, 6em7 SPUD (0.00)
Posted by Gary Kaufman on 2003-02-11, 09:05:25 (130.189.66.61)
Bas - I built a dc coupled 6EM7 amp and have been VERY impressed at how good it sounds. Schematic and details below. .......
455: Tubes Asylum, Re: Dynaco A410? (0.00)
Posted by Gary Kaufman on 2003-02-11, 02:10:56 (68.168.40.176)
8KCT output transformer, generally EL84 or 6V6 Full specs in the Dynaco transformer catalog downloadable via my website below... .......
456: Tube DIY Asylum, Re: Gary! what type of caps you use for snubbing across the chokes <nt> (0.00)
Posted by Gary Kaufman on 2003-02-10, 14:33:10 (68.168.40.176)
I didn't have any .22uf caps with sufficient voltage rating, so used a pair of .47uf/630v metal film caps in series. It essentially gives a .22uf/1200v part. I didn't add any balancing resistors (I pr .......
457: Tube DIY Asylum, Re: Two and a half Inductor Questions (0.00)
Posted by Gary Kaufman on 2003-02-09, 15:59:06 (68.168.40.62)
Actually a minor point to add - Transformers will vary the output voltage between no load and full load. Although better transformers are pretty well regulated, others are pretty poor. For example, th .......
458: Tube DIY Asylum, Re: Choke Filters, and the Buzz... (0.00)
Posted by Gary Kaufman on 2003-02-09, 12:02:40 (68.168.40.62)
Lewis - I didn't change the power supply - always 800vdc. I started out running the 211's quite lightly - around 40ma. The GE spec sheet for 211's shows a class A operating point of 750v/34ma. I'm now .......
459: Tube DIY Asylum, Re: Choke Filters, and the Buzz... (0.00)
Posted by Gary Kaufman on 2003-02-09, 11:52:40 (68.168.40.62)
Brian - I didn't - the effort of disconnecting the power supply and dragging the beast over to my workbench discouraged me! Intellectually I can't understand what the second half would do - especially .......
460: Tube DIY Asylum, Re: Choke Filters, and the Buzz... (0.00)
Posted by Gary Kaufman on 2003-02-08, 19:36:42 (68.168.40.62)
Thanks to all for the ideas! As always this group is a wealth of information. I tried two things tonight, with pretty good results. First I placed a small felt gasket under the choke to decouple it fr .......
461: Tube DIY Asylum, Re: Choke Filters, and the Buzz... (0.00)
Posted by Gary Kaufman on 2003-02-08, 19:31:41 (68.168.40.62)
Josh - Thanks for the kind words, but my design doesn't compare to some of your beautiful work!! .......
462: Tube DIY Asylum, Re: Choke Filters, and the Buzz... (0.00)
Posted by Gary Kaufman on 2003-02-08, 19:11:37 (68.168.40.62)
Vinnie - Outputs are Mikey's FS-100's. Pretty awesome! (Thanks to Grover who sold me the pair) I'm very happy with the dual PS/output chassis setup. It took me a while to find connectors I felt safe w .......
463: Tube DIY Asylum, Choke Filters, and the Buzz... (0.00)
Posted by Gary Kaufman on 2003-02-08, 13:44:19 (68.168.40.62)
My latest amp project is a 6C45 choke loaded driving a 211, B+ is 800vdc, driving the 211's at 60ma. Nite View Thus far I'm very pleased, but am getting a small amount of buzzing from the first choke .......
464: Tubes Asylum, Re: Parts substitution on MKIII input boards (0.00)
Posted by Gary Kaufman on 2003-02-06, 14:36:40 (130.189.41.169)
Chris - What do the original pot's look like? I just purchased a large lot of surplus including 1K's of potentiometers. If I have something that will work I can send you a pair. .......
465: Tubes Asylum, Re: Bendix 5947 Tube. Is it a 6SN7? (0.00)
Posted by Gary Kaufman on 2003-02-04, 18:15:17 (68.168.40.62)
The 5947 is a rectifier according to my records, 4.4V @ 1.75A filament. I couldn't find any other specific info, but the pinout should be easy to tell by visual inspection. Won't work well as a 6SN7.. .......
466: Vintage Asylum, Re: Is the 350A anything like an 807? (6L6 family) (0.00)
Posted by Gary Kaufman on 2003-02-04, 18:09:12 (68.168.40.62)
Doug - The 350A is essentially a 807 on steroids. Should be a wonderful tube, and probably better than a 350B. 6.3V@1.6A, Gm 7.1-8.5mS, 30W Apparently it was made by WE, STC and NEC according to Sible .......
467: Tubes Asylum, Re: CEI 6BQ5 / EL84 / 7189's Germany . How do these compare with Amperex? (0.00)
Posted by Gary Kaufman on 2003-02-02, 17:13:52 (68.168.40.62)
Glad to hear that - I've seen too many mislabeled EL84's, and the vast majority are Russian types labeled "Made in Germany". .......
468: Tubes Asylum, Re: CEI 6BQ5 / EL84 / 7189's Germany . How do these compare with Amperex? (0.00)
Posted by Gary Kaufman on 2003-01-31, 15:18:35 (130.189.41.169)
Probably Russian... Most Real German tubes have made in w. germany. Does it look like the above? Typical Russian EL84's - pins are sharp, the bulb a bit larger than average and the getter a small con .......
469: Tube DIY Asylum, Re: 810 (0.00)
Posted by Gary Kaufman on 2003-01-30, 12:59:54 (130.189.41.169)
Berlin - It is really superb with some music. It has good punch and authority, but gets harsh when driven hard. Overall I'm very glad I built it, but I still pull out the 46's or 2A3's for most music. .......
470: Tube DIY Asylum, Re: 810 (0.00)
Posted by Gary Kaufman on 2003-01-30, 12:34:19 (130.189.41.169)
Lazarus is alive and well! I dropped out of audio for a few months after moving and then dealing with a dry well etc. I'm finally getting back to soldering. Ironically, I was thinking of you this past .......
471: Tube DIY Asylum, Re: diy 45 tube tester ? (0.00)
Posted by Gary Kaufman on 2003-01-30, 12:28:42 (130.189.41.169)
Steve Bench's site has a DIY tube tester, easily adapted to 45's etc. There's a link to Steve's site on my webpage. Alan Douglas's Book on Tube Testers and test equipment (available thru Sonoran publi .......
472: Tube DIY Asylum, Re: Dyna ST-70 bias (0.00)
Posted by Gary Kaufman on 2003-01-26, 13:22:50 (68.64.101.209)
Yup, should have. You might have really leaky coupling caps. Thinking out loud... The 0.8v that you're measuring isn't bias, but the resulting voltage drop across a 15.6 ohm resistor. With 1.56v acros .......
473: Tube DIY Asylum, Re: Dyna ST-70 bias (0.00)
Posted by Gary Kaufman on 2003-01-26, 07:24:44 (68.64.101.209)
Nope - should be in range in about 45 seconds and settle to a rock stable value in 15-20 minutes. Sounds like you may need to adjust the bias divider to give you a "less negative" adjustment range. If .......
474: Tube DIY Asylum, Re: Mercury Rectifiers and the Frozen Northeast! (0.00)
Posted by Gary Kaufman on 2003-01-26, 07:14:58 (68.64.101.209)
Gosh, and cover up the beautiful blue glow? Then again, you may be onto something. I'm sure you can convince someone that they improve the pace, midrange, tessitura, soundstaging, and dynamics of the .......
475: Tube DIY Asylum, Re: Mercury Rectifiers and the Frozen Northeast! (0.00)
Posted by Gary Kaufman on 2003-01-24, 14:08:33 (130.189.41.169)
I'm in the other Amherst - Amherst, NH (just west of Nashua) Local Amherst NH weather from my weather station Once it defrosts a bit I'll organize a get together - I finally have a large enough listen .......
476: Tube DIY Asylum, Mercury Rectifiers and the Frozen Northeast! (0.00)
Posted by Gary Kaufman on 2003-01-24, 11:16:01 (130.189.41.169)
It got down to -3 last pm, and hasn't been above freezing in 2 weeks. Adds yet another twist in using mercury rectifiers. My music room is a large space which gets pretty cold. I've been using a progr .......
477: Tubes Asylum, Re: Really really dumb question about testing the 83 in my tube tester (0.00)
Posted by Gary Kaufman on 2002-11-05, 07:52:11 (130.189.66.41)
Chris - I've replaced 83's in many TV7's and 539b/c's and all have worked nicely in my experience. It's the 5Y3 that really can't be solid-state. Just curious which tester's gave you problems? As a .......
478: Vintage Asylum, Re: I just found a Fisher FM-200B Tuner at the thrift store! (0.00)
Posted by Gary Kaufman on 2002-09-12, 16:45:00 (24.48.168.9)
It is highly likley that all tubes are fine. Except for the pair of 6CW4 nuvistors all tubes in a FM200B are inexpensive and easy to locate. The quality of the original Fisher tubes is better than any .......
479: Tubes Asylum, Re: Tired of the same old tubes.... (0.00)
Posted by Gary Kaufman on 2002-09-04, 09:47:54 (130.189.48.212)
Well, my "current" setup is a linestage using 407A's, and an amp using 826's. My other "favorite" output tube is a 46. I also have amps that use 6C45, 1626, 6S4, 6384, 6EM7 and 12BH7 as output tubes. .......
480: Tubes Asylum, Re: Don't Pull all tubes! (0.00)
Posted by Gary Kaufman on 2002-09-04, 09:37:49 (130.189.48.138)
Well, power transformer is probably toast :( To be sure you can disconnect all secondary leads and retest, or bring it up on a variac while measuring secondary voltages. Magnequest makes a direct subs .......
481: Tubes Asylum, Don't Pull all tubes! (0.00)
Posted by Gary Kaufman on 2002-09-03, 05:22:16 (130.189.66.22)
Steve - Respectfully, I disagree with the second step of your recommendations. Running an ST70 with only the rectifier can cause the B+ to rise above the ratings of the filter cap and destroy it in ma .......
482: Tube DIY Asylum, Re: 5AR4 Issues (0.00)
Posted by Gary Kaufman on 2002-08-09, 09:45:25 (130.189.48.130)
First, consider running your power supply design thru Duncan Amps' simulator (www.duncanamps.com). It will quickly tell you if you are outside of a 5AR4's parameters and is a fantastic program (free t .......
483: Tube DIY Asylum, Re: Sound Characteristics of the Less Common Transmitting Tubes (0.00)
Posted by Gary Kaufman on 2002-08-07, 17:15:31 (68.64.101.149)
About 5 watts. - Gary .......
484: Tube DIY Asylum, Re: Sound Characteristics of the Less Common Transmitting Tubes (0.00)
Posted by Gary Kaufman on 2002-08-06, 08:30:29 (130.189.65.126)
I constructed a version of Shishido's 826 inverted interstage amp a few months ago. It has tremendous authority and presence but lacks the fine detail of a 2A3, 45 or 46 amp. The 826 is also a visuall .......
485: Tube DIY Asylum, Re: skinny power cord for dynaco mk IV (0.00)
Posted by Gary Kaufman on 2002-07-30, 07:18:36 (130.189.66.22)
Don't laugh, but the least expensive option is often to pick up some nice quality polarized extension cords and cut off the ends. Although 3 wire systems make sense from a safety point of view, they .......
486: Tube DIY Asylum, Re: 01a tubes (0.00)
Posted by Gary Kaufman on 2002-05-31, 07:08:17 (130.189.48.130)
01A's generally refer to the "ST" shaped bulbs 201A/301A/401A are generally globe, the first letter is irrelevant, for example RCA is 201, Cunningham 301, Deforest 401 etc. UV refer to the short pin t .......
487: Tubes Asylum, Re: 83 Mercury Vapor Rectifiers (0.00)
Posted by Gary Kaufman on 2002-05-16, 17:46:36 (65.96.243.57)
Vincent - Don't bother with an 83 in a Hickok tester. A simple adapter using 1N4007's works fine, and reduces the load on the power transformer. Alan Douglas's Book on Tube testers has a diagram for t .......
488: Tubes Asylum, Re: 50L 6-GT guitar amp (0.00)
Posted by Gary Kaufman on 2002-05-11, 13:23:47 (65.96.243.57)
Just a note of caution - this is most likely a series string design, eg no power transformer. If so, it isn't the safest. At the very least adding a polarized power cord (or better an isolation transf .......
489: Tubes Asylum, Re: Anyone else having problems with NOS 805's? (0.00)
Posted by Gary Kaufman on 2002-05-05, 05:51:48 (65.96.206.132)
Mark - I have limited experience with 805's, but have more experience with 211's and 826's. Most thoriated tungsten tubes have very brittle filaments, and many have been knocked around enough to brea .......
490: Tube DIY Asylum, Re: You're Right! (0.00)
Posted by Gary Kaufman on 2002-04-20, 18:19:22 (65.96.206.132)
Eli - Another cute trick for today's higher line voltages is to substitute a 50A5 for the 35A5 - same pinout and very close electrically except for the extra 15v drop in the filament. .......
491: Tube DIY Asylum, I'm back... (0.00)
Posted by Gary Kaufman on 2002-04-12, 09:16:22 (130.189.48.131)
Sorry I didn't respond sooner - I'm in the midst of moving and life has been hectic! I'm seriously behind on posting projects to my website, and probably won't catch up till the summer. I originally .......
492: Tubes Asylum, Re: What are the odds....... (0.00)
Posted by Gary Kaufman on 2002-04-10, 08:29:08 (130.189.48.131)
Radio Shack will honor the warranty. You'll unfortunately get a russian or chinese 5AR4 in return, but better than nothing. Your local RS will have to call Texas and return the dud. You'll get a tube .......
493: Vintage Asylum, Hifi Haven? (0.00)
Posted by Gary Kaufman on 2002-04-09, 07:24:26 (130.189.66.16)
That New Brunswick NJ store wouldn't happen to be Hifi Haven? I remember that place fondly from High School in the 1970's. .......
494: Tubes Asylum, Re: TV-2 more accurate than TV-7 ? (0.00)
Posted by Gary Kaufman on 2002-04-09, 02:00:45 (65.96.206.132)
Doc - Alan's notes on adapting 575's is in his book on test gear and tube testers, available thru http://www.sonoranpublishing.com/ .......
495: Tube DIY Asylum, Re: ACCO TD-303 tranie (0.00)
Posted by Gary Kaufman on 2002-04-09, 01:47:19 (65.96.206.132)
Bruce - Are you sure it's a ACCO TD-303 and not an ACRO TO-305 or TO-300? Acrosound's 5881 PP output transformer was the TO-300, the TO-305 was the same transformer with the optional 125/500 ohm .......
496: Tube DIY Asylum, Re: 807/1625PP schematic request (0.00)
Posted by Gary Kaufman on 2002-04-01, 17:22:43 (65.96.206.132)
Mikey - I can extract the circuit from the pdf file and email it - let me know where to send it. .......
497: Tubes Asylum, Re: Any sources for 8005 tubes? (0.00)
Posted by Gary Kaufman on 2002-03-28, 20:17:32 (65.96.206.132)
The 8005 was essentially a re-pinned 203 with 4 pin base and top cap. One of the Svetlana 811/572-30 should be adaptable, although not a straight forward change. Both www.tubeworld.com and www.tubesan .......
498: Tube DIY Asylum, Re: Unbalanced load on Mercury Vapor Rectifiers? (0.00)
Posted by Gary Kaufman on 2002-03-16, 11:04:57 (65.96.206.132)
Doesn't sound right - if you swap the 866's does the glowing tube follow the "tube" or the "socket"? .......
499: Tube DIY Asylum, Re: Substitute for 1/2 a 12AX7? (0.00)
Posted by Gary Kaufman on 2002-03-08, 20:41:31 (65.96.206.132)
6AV6 has the characteristics of a 12AX7 in a single 7 pin minature. There are also 2 diodes which can be strapped to the plate (ignored). - Gary .......
500: Vintage Asylum, Re: advent 300 repairs (0.00)
Posted by Gary Kaufman on 2002-02-28, 18:15:59 (65.96.206.132)
One of the biggest problems with the Advent 300 are the electrolytic caps. Most were of mediocre quality and often there were 16v rated parts on 15v unregulated voltage rails. I remember spending hour .......
Found total of 500 records, Query: , Author: Gary Kaufman in All Forums, Time: 1 sec.