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1: Tube DIY Asylum, RE: DIY Lettering For Chassis. (0.00)
Posted by DanK tubes on 2024-03-31, 17:32:06 (104.28.124.183)
I've had the same question in the past and I'm curious what others do. I've thought about water transfer decals, but haven't tried them. Perhaps those would work for you. Dan .......
2: Vintage Asylum, RE: Ampex A423 Console The Longest Restoration (0.00)
Posted by DanK tubes on 2024-01-07, 15:31:47 (162.236.246.57)
Cool project. I rebuilt an Ampex console ~20 years ago. Mine was from 1959. Wish I hadn't got rid of it. Here's a copy of the pre-amp schematic that I used. cheers .......
3: Tube DIY Asylum, RE: Recent Project Completed (0.00)
Posted by DanK tubes on 2021-11-21, 13:05:07 (162.236.246.57)
Great work TK. Looks beautiful. Enjoy! .......
4: Tube DIY Asylum, RE: Is the B plus delayed (0.00)
Posted by DanK tubes on 2021-08-21, 12:33:37 (162.236.246.57)
HI Johno, The K&K power supply is really nice. There is a relay timer circuit to delay the B+. It's adjustable with a resistor change. The default is 45 sec delay. It's spec'd at 600V max output volta .......
5: Tube DIY Asylum, RE: EF86 - 300B XLS "Hybrid" project (0.00)
Posted by DanK tubes on 2021-08-18, 16:45:03 (162.236.246.57)
Yes, you're correct, Ale's boards do allow connection with fixed bias. I just chickened out. I was worried about fixed bias thermal runaway on an expensive output tube. Maybe I'll build up the courage .......
6: Tube DIY Asylum, RE: Taming the SIC diodes (0.00)
Posted by DanK tubes on 2021-08-18, 11:04:33 (162.236.246.57)
Hi Andy, Thanks for the suggestion. Definitely something I can tinker with. Gordon Rankin had a nice write up on fully/partially bypassed cathode circuits, in is Single 807 Amplifier article (Sound P .......
7: Tube DIY Asylum, RE: EF86 - 300B XLS "Hybrid" project (0.00)
Posted by DanK tubes on 2021-08-18, 10:54:09 (162.236.246.57)
Hi Douglas, The Gyrator is Directly Coupled to the SiC source follower board. The SiC source follower is Cap Coupled to the 300B grid. Cheers, Dan .......
8: Tube DIY Asylum, EF86 - 300B XLS "Hybrid" project (0.00)
Posted by DanK tubes on 2021-08-17, 20:20:29 (162.236.246.57)
I thought I'd share my latest project here. I crammed in tons of solid state for this one. Not sure if it's really a Hybrid amp, but it's close. Big shout out to Ale M. I used his Gyrators to load th .......
9: High Efficiency Speaker Asylum, RE: Altec 414A (0.00)
Posted by DanK tubes on 2019-04-19, 21:48:19 (104.50.224.37)
Oh no Abe! Sorry to hear that. Are those the 414's I sold you a while back? Great Plains can help to rebuild old Altecs. Cheers, Dan .......
10: High Efficiency Speaker Asylum, I took classes from Dr. Leach in college (0.00)
Posted by DanK tubes on 2018-09-11, 21:56:40 (104.50.224.37)
he was such a helpful and patient teacher. Thanks for the link. Dan .......
11: Tube DIY Asylum, RE: Modified Duttman/RCA phono stage (0.00)
Posted by DanK tubes on 2018-04-25, 22:05:48 (104.50.224.37)
Thank you TK. The sub chassis is G10 circuit board. .......
12: Tube DIY Asylum, Modified Duttman/RCA phono stage (0.00)
Posted by DanK tubes on 2018-04-24, 18:49:32 (104.50.224.37)
I've been tinkering with my Duttman RCA phono stage. I upgraded the output stage to use one of Ale Moglia's SIC Source Followers. I also added a Cinemag output transformer for galvanic iso .......
13: Tube DIY Asylum, RE: RCA phono stage question - (my build) (0.00)
Posted by DanK tubes on 2018-04-24, 18:41:27 (104.50.224.37)
Hi Pete, actually, your right. I've been tinkering with mine and just measured again. I get 155V on the plate of the first stage and 150V on the plate of the second stage. Cheers, Dan .......
14: Tube DIY Asylum, RE: RCA phono stage question - picture (my build) (0.00)
Posted by DanK tubes on 2018-04-10, 08:53:31 (104.50.224.37)
Nice project Pete. I'm using a 12ax7 tube, my B+ is 250V, and I get ~170 volts at the plate of each section. Best regards, Dan .......
15: Tube DIY Asylum, Thank you all... and a follow up question (0.00)
Posted by DanK tubes on 2018-04-06, 19:32:21 (104.50.224.37)
Thank you all for the explanation. I learn so much from this forum. I took apart the amp today and measured ~1V bias and ~0.7mA current on the 2nd stage. My DMM isn't very accurate but it's close .......
16: Tube DIY Asylum, RCA phono stage question (0.00)
Posted by DanK tubes on 2018-04-05, 21:39:23 (104.50.224.37)
Hi all, Based on Eli's excellent suggestion, I built a version of this RCA phono stage with MOSFET follower output. I works great, but I'm still puzzled by the design. The second 6n2p stage has no .......
17: Tube DIY Asylum, RE: 47 sound (0.00)
Posted by DanK tubes on 2018-01-18, 08:10:25 (104.50.224.37)
Hi sser2, thanks for the comments. Do you know the operating points for your 47's? cheers, dan .......
18: Vintage Asylum, RE: Ampex 6973 mono block amp output transformer wanted (0.00)
Posted by DanK tubes on 2017-09-30, 12:51:20 (104.50.224.37)
Hi Hans, This thread is a bit old, but if your still looking, I have a pair of Ampex 6973 output transformers that I'm willing to part with. Dan .......
19: Tube DIY Asylum, RE: CCS Mu output question (0.00)
Posted by DanK tubes on 2017-03-08, 18:48:42 (104.50.224.37)
OK, got it. I see there is no free lunch. Thanks Tre, Dan .......
20: Tube DIY Asylum, CCS Mu output question (0.00)
Posted by DanK tubes on 2017-03-05, 15:17:09 (104.50.224.37)
Hi all, I have a question about the Mu follower output of a cascade CCS. The Mu output should be able to drive a low impedance. What if you were to take a low current driver tube, say a 12ax7, and loa .......
21: High Efficiency Speaker Asylum, RE: My New 414 In 614 With Azura 425 (Long) (0.00)
Posted by DanK tubes on 2016-05-17, 21:57:19 (104.50.224.37)
Nice set up Abe! I think I recognize those 414's. Enjoy, Dan .......
22: MagneQuest/Peerless Forum, Thank you! nt (0.00)
Posted by DanK tubes on 2015-08-18, 20:02:49 (104.50.224.37)
Nt .......
23: MagneQuest/Peerless Forum, plate choke physical dimensions (0.00)
Posted by DanK tubes on 2015-08-17, 14:20:22 (199.255.44.5)
Hi all, Does anyone know the physical dimensions, and mounting hole spacing, for the EXO-003 and BCP-15 plate chokes? Thanks, Dan .......
24: Tube DIY Asylum, Thanks guys! (nt) (0.00)
Posted by DanK tubes on 2014-11-20, 15:03:49 (199.255.44.5)
nt .......
25: Tube DIY Asylum, SE Pentode output stage question (0.00)
Posted by DanK tubes on 2014-11-19, 22:35:58 (63.249.111.235)
Hi all, I have a nice pair of single ended output transformers that are designed for parallel feed, and I was thinking of using them on a SEP output stage. However, I suspect a pentode won't work so w .......
26: Tube DIY Asylum, RE: How low do we have to go??? (0.00)
Posted by DanK tubes on 2014-11-19, 18:34:06 (199.255.44.5)
Here is an interesting article from EE times. Check out page 3. "If an amplifier has high and low frequency roll-offs which begin too close to the audible frequency extremes, it will exhibit phase shi .......
27: MagneQuest/Peerless Forum, RE: Altec Transformer 16167-Q Specs ??? (0.00)
Posted by DanK tubes on 2014-05-23, 21:01:08 (63.249.111.235)
You can check in the Peerless catalogs here. I believe the Q was to designate the case type. Good luck, Dan .......
28: High Efficiency Speaker Asylum, RE: My Z19 Xover parts for my Horn speakers are on the way! (0.00)
Posted by DanK tubes on 2014-05-19, 12:47:48 (199.255.44.5)
I built a pair of Z19 crossovers for use in and Econowave type project with GPA 416 and JBL constant directivity horns. I added an additional 19kHz notch filter to tame a BMS 4555 driver. This is .......
29: Tube DIY Asylum, Thanks Ralph! (nt) (0.00)
Posted by DanK tubes on 2014-03-12, 13:38:10 (199.255.44.5)
Thanks Ralph! Dan .......
30: Tube DIY Asylum, RE: Even with a CCS (0.00)
Posted by DanK tubes on 2014-03-12, 12:42:38 (199.255.44.5)
Hi Ralph, Yes, matching the mu is a problem. Seems all phase splitting solutions have some drawback. I'll probably tinker with it some day, but for now it sounds pretty good. Also, the CCS is a cascod .......
31: Tube DIY Asylum, RE: CCS (0.00)
Posted by DanK tubes on 2014-03-11, 18:28:20 (63.249.111.235)
Hi there, For these amps, the current through R8 is ~1.2mA. I purchased the Compact Cascode CCS kits from Kevin, and soldered them up. The instructions show how to add an additional resistor to lower .......
32: Tube DIY Asylum, RE: Excellent job ! (0.00)
Posted by DanK tubes on 2014-03-11, 15:13:55 (199.255.44.5)
Thanks Mike! Yes, I agree on film caps. I just need to figure out how to squeeze them into that tiny chassis... Dan .......
33: Tube DIY Asylum, RE: Ampex monoblock rebuild (0.00)
Posted by DanK tubes on 2014-03-11, 13:31:27 (199.255.44.5)
Thanks Tre. I've had two Ampex consoles with these 6973 monoblocks. They were high end consoles. One of them cost $2k in 1959. However, in one console, the speakers were 16ohm 3-ways and the other us .......
34: Tube DIY Asylum, Ampex monoblock rebuild (0.00)
Posted by DanK tubes on 2014-03-11, 11:38:44 (199.255.44.5)
A while back I posted about rebuilding my Ampex 6973 monoblocks and y'all gave me some good ideas. This is what I wound up with. Here is the original Ampex schematic: I changed a few things. Fi .......
35: Tube DIY Asylum, RE: Apples and oranges (0.00)
Posted by DanK tubes on 2014-03-07, 14:44:06 (199.255.44.5)
"Jack Elliano says that silver (in the secondary of an output transformer) has a higher sensitivity to flux change than copper." --Tre Hi Tre, Here is the quote copied from Jack's web page: "Due to .......
36: Tube DIY Asylum, "current etiquette" (0.00)
Posted by DanK tubes on 2014-02-24, 22:53:28 (63.249.111.235)
he he he. good one. i didn't see a foul in your post. dan .......
37: SET Asylum, And another paper (0.00)
Posted by DanK tubes on 2013-10-15, 14:35:22 (199.255.44.5)
Thanks for the link. Here is another good one .......
38: SET Asylum, RE: Ground Loops and Isolation Transformers....................... (0.00)
Posted by DanK tubes on 2013-10-14, 15:25:38 (199.255.44.5)
Hi CT, In the end, I wound up soldering them up like Mike suggested, above and here: http://www.6moons.com/industryfeatures/mq/mq.html I added an alps attenuator as seen on the link and made a kind of .......
39: SET Asylum, RE: Ground Loops and Isolation Transformers....................... (0.00)
Posted by DanK tubes on 2013-10-14, 13:42:34 (199.255.44.5)
Hi CT, at one point I was fighting a ground loop problem and wound up buying some Ampex 20k:20k bridging input transformers for the task. These are octal mount jobs, probably made by Altec. They work .......
40: Tube DIY Asylum, Thanks Mike! (0.00)
Posted by DanK tubes on 2013-07-19, 22:41:51 (63.249.111.139)
that made my day! .......
41: High Efficiency Speaker Asylum, +1 (nt) (0.00)
Posted by DanK tubes on 2013-07-02, 22:53:45 (63.249.111.139)
me too .......
42: Tube DIY Asylum, Thanks Eli! (nt) (0.00)
Posted by DanK tubes on 2013-06-20, 20:06:30 (63.249.111.139)
nt .......
43: Tube DIY Asylum, Thanks Eli! nt (0.00)
Posted by DanK tubes on 2013-06-19, 09:49:53 (199.255.44.5)
nt .......
44: Tube DIY Asylum, RE: Ampex 6973 mod question... Eli? (0.00)
Posted by DanK tubes on 2013-06-18, 14:48:31 (199.255.44.5)
Thanks Tom. I guess a CCS is out. I don't think I can equalize the loads with that DC coupled driver circuit. What do you think C3 is for? Dan .......
45: Tube DIY Asylum, Ampex 6973 mod question... Eli? (0.00)
Posted by DanK tubes on 2013-06-18, 11:05:04 (199.255.44.5)
I have a pair of Ampex 6973 monoblock amps that I've been tinkering with. I've added more filtering capacitance and bumped up the coupling cap size with some 0.22 K40 pios I had on hand. I also swappe .......
46: MagneQuest/Peerless Forum, Thanks Paul. (nt) (0.00)
Posted by DanK tubes on 2013-05-30, 08:16:26 (199.255.44.5)
nt .......
47: MagneQuest/Peerless Forum, RE: BAC-80 questions (0.00)
Posted by DanK tubes on 2013-05-22, 22:44:32 (63.249.110.86)
Thanks Matt. Wow, 105H is quite a choke. I wish I had enough room for it in my current chassis. Good to know for future builds. Dan .......
48: MagneQuest/Peerless Forum, BAC-80 questions (0.00)
Posted by DanK tubes on 2013-05-20, 17:58:23 (199.255.44.5)
I'm interested in picking up a pair of plate chokes to be used with a 300B, at 60mA. The BAC-80 looks like a nice choice for this. Can anyone provide the physical dimensions and mounting hole cc spaci .......
49: Tube DIY Asylum, thanks Tre (nt) (0.00)
Posted by DanK tubes on 2012-12-23, 13:11:31 (63.249.110.86)
nt .......
50: Tube DIY Asylum, 6v6 triode curves (0.00)
Posted by DanK tubes on 2012-12-23, 09:36:03 (63.249.110.86)
Hi Tre, 6v6 triode looks pretty linear to me. Dan .......
51: High Efficiency Speaker Asylum, RE: Any plans to try larger horn with (800Hz Xover? (0.00)
Posted by DanK tubes on 2012-12-10, 22:11:19 (63.249.110.86)
Yes, I've heard great things about Dr. Geddes speakers. And that paper is a great read. It's possible that I'll try a larger horn/lower crossover. I think there are good arguments for going either way .......
52: High Efficiency Speaker Asylum, RE: My latest HE speaker build (0.00)
Posted by DanK tubes on 2012-12-10, 19:55:36 (63.249.110.86)
Thanks for the tip. I was thinking about this, but needed to figure out how to attach it inside the horn. Dan .......
53: High Efficiency Speaker Asylum, RE: My latest HE speaker build (0.00)
Posted by DanK tubes on 2012-12-10, 19:06:15 (63.249.110.86)
Hi Frank, They are both nice and it's hard to say without a side by side. The 604 has scary imaging on some recordings. Both of them make music that's 3D and decoupled from the cabinet. But, I really .......
54: High Efficiency Speaker Asylum, RE: Get rid of the L-Pads (0.00)
Posted by DanK tubes on 2012-12-10, 18:54:20 (63.249.110.86)
Yeah, I'll replace them with fixed resistors once I get them dialed in. Thanks, Dan .......
55: High Efficiency Speaker Asylum, RE: What did you think of the 612 cabinets? (0.00)
Posted by DanK tubes on 2012-12-10, 18:53:16 (63.249.110.86)
The 612 sounds surprisingly good even though it only plays down to ~40Hz or so. The thing is, the 604 is so beamy, you really need to get them up to ear level. With the 612, that means a large stand o .......
56: High Efficiency Speaker Asylum, My latest HE speaker build (0.00)
Posted by DanK tubes on 2012-12-09, 22:08:32 (63.249.110.86)
I've just finished up a new HE speaker project and thought I would share my experience. A while back I built up some MLTL corner cabinets for my Altec 604-8k speakers. The MLTL is essentially the Ste .......
57: Tube DIY Asylum, another satisfied user (0.00)
Posted by DanK tubes on 2012-12-08, 20:15:40 (63.249.110.86)
I've also built this phono stage and am happy with the results. Dan .......
58: Tube DIY Asylum, RE: Old Radio Shack Catalogs! cool site (0.00)
Posted by DanK tubes on 2012-11-28, 17:38:00 (199.255.44.5)
Thanks for the link. Wow, back in 1940 you could get a type 50 tube for 92 cents! Dan .......
59: Water Cooler, RE: I just got home from a local Democratic fundraiser. (0.00)
Posted by DanK tubes on 2012-10-31, 13:19:58 (199.255.44.5)
It's not just Democrats that have this kind of turnout. I think in general it's an older crowd that actually gets out to do the actual work. Weather it's old church folks, old union folks, or old hipp .......
60: MagneQuest/Peerless Forum, RE: Full catalog (0.00)
Posted by DanK tubes on 2012-10-26, 21:36:22 (63.249.110.86)
Hey twysted, Just curious, how you are using the b7-15k. thanks, dan .......
61: Tube DIY Asylum, RE: Commenting on Tube Sonics ...... (0.00)
Posted by DanK tubes on 2012-10-25, 11:12:35 (199.255.44.5)
I keep thinking about your comments that "reduced dissipation" = "relaxed sounding". I'm just wondering why you think this is always true. I can see how changing operating points can change the linear .......
62: Tube DIY Asylum, hahaha, good one! (nt) (0.00)
Posted by DanK tubes on 2012-10-04, 22:47:10 (63.249.110.86)
nt .......
63: High Efficiency Speaker Asylum, RE: Voigt corner horn..interest? (0.00)
Posted by DanK tubes on 2012-09-25, 13:35:44 (199.255.44.5)
I have detailed plans for the 1936 Voigt Home Constructors Horn. Let me know if you would like a copy. Dan .......
64: Tubes Asylum, RE: An off-the-wall possibility... (0.00)
Posted by DanK tubes on 2012-09-11, 20:15:48 (63.249.110.86)
A file seems like an excellent way to propagate a crack through to vacuum. I agree that rounding the sharp corner is good, but a file is not a good way to do this. Maybe a chemical etch with HF acid.. .......
65: Tubes Asylum, RE: Genalex KT66 with cracked glass (0.00)
Posted by DanK tubes on 2012-09-08, 11:18:11 (63.249.110.86)
Epoxy will not hold vacuum if the glass part does fail, so the only advantage of epoxy is to keep the glass fixed in place to keep the crack from propagating any further. However, you should think abo .......
66: Tube DIY Asylum, RE: I just can't shut up (0.00)
Posted by DanK tubes on 2012-09-04, 22:13:14 (63.249.110.86)
I'm sure they are great transformers but WTF is this all about: "Silver and partial silver windings offer a 200% increase in sensitivity over copper as a secondary, resulting in an increased in music .......
67: SET Asylum, RE: 4P1L in pentode (0.00)
Posted by DanK tubes on 2012-08-23, 19:39:19 (63.249.110.86)
Thanks Andy. If you don't mind, please report back with the pentode results. Dan .......
68: SET Asylum, RE: EML 20A/B and AV20B-SL drivers for 300B SET amp (0.00)
Posted by DanK tubes on 2012-08-23, 11:46:48 (199.255.44.5)
Hi Andy, I've been watching you chronical your experiences with PP and SET amps (here and DIY audio). Sounds like you have been making some nice progress. I like your latest idea of using the 4P1L as .......
69: Tube DIY Asylum, Ha! (0.00)
Posted by DanK tubes on 2012-08-10, 22:37:26 (63.249.111.174)
good one Jeff! dan .......
70: Vintage Asylum, RE: anyone recognize the console in background? (0.00)
Posted by DanK tubes on 2012-07-27, 13:20:10 (199.255.44.5)
Are those bottles sticking out of cylinders 3, 4, 5, and 6? Looks like an aluminum block. Pretty cool! Dan .......
71: SET Asylum, Thanks Tre! (0.00)
Posted by DanK tubes on 2012-06-26, 19:49:20 (63.249.110.86)
Saved me some trouble. Dan .......
72: SET Asylum, Hey Tre! (0.00)
Posted by DanK tubes on 2012-06-26, 13:31:56 (199.255.44.5)
I hear you. It boggles the mind how these threads just keep coming up. No one ever mentions how the DC coupled 2A3 amps in question sound, the arguments are always about the unproven claims of "perfor .......
73: Tube DIY Asylum, RE: audio output transformer design (0.00)
Posted by DanK tubes on 2012-06-20, 10:28:17 (199.255.44.5)
There was an old reprinted article, published in Sound Practices magazine, that told you how to rewind a power transformer into a push-pull output transformer. It was a very rudimentry article. I know .......
74: Tube DIY Asylum, RE: Electromechanical analogs (0.00)
Posted by DanK tubes on 2012-06-15, 13:19:43 (199.255.44.5)
Hi Mike, You might be right. I remember reading that statement somewhere, but honestly I never really thought about it. Hope you and your family are getting along OK. Dan .......
75: Tube DIY Asylum, RE: 1/4 the horsepower (0.00)
Posted by DanK tubes on 2012-06-14, 21:53:47 (63.249.110.86)
"How does it sound?" Goldstar's, and big singles in general, definitely have a distinctive sound. I love it when you rev it up, let off the throttle and let it wind down. It's kind of an aggressive, .......
76: Tube DIY Asylum, RE: Electromechanical analogs (0.00)
Posted by DanK tubes on 2012-06-14, 21:35:00 (63.249.110.86)
way to keep it on topic Henry! BTW, the duck's 90 degree v-twin is canted froward, opposed to a straight up V like a Harley or Moto Guzzi, giving it a lower center of gravity. Dan .......
77: Tube DIY Asylum, 1/4 the horsepower (0.00)
Posted by DanK tubes on 2012-06-14, 18:09:22 (63.249.110.86)
but just as much fun 1954 BSA CB34, 500cc single. i love my exhaust notes in mono Enjoy! Dan .......
78: Tubes Asylum, 80000 feet! (0.00)
Posted by DanK tubes on 2012-06-06, 21:25:55 (63.249.110.86)
Wow, that is in the stratosphere. Guess these things were to be used on rockets or ICBMs. Cool stuff! Dan .......
79: Tube DIY Asylum, RE: Yes, Condenser=Capacitor, just as Choke=Inductor (0.00)
Posted by DanK tubes on 2012-06-04, 12:19:00 (199.255.44.5)
just like the crusty old uuF. Dan .......
80: Vinyl Asylum, Sleigh Bells! (0.00)
Posted by DanK tubes on 2012-06-01, 22:47:43 (63.249.110.86)
Yes! I've got a sweet spot for that band. I can only take so much at a time, but when I'm in the mood there is nothing else better. I've only got them on MP3 but I might just have to pick up some of t .......
81: High Efficiency Speaker Asylum, RE: Altec Model 19 Empty Cabinets - What Would You Do? (0.00)
Posted by DanK tubes on 2012-05-30, 11:03:48 (199.255.44.5)
Hi Paully, Guess there are always trade offs. The 902 is a brand new off the shelf unit. I often find that vintage units need to be rebuilt, and that's an extra cost. The 902 has better high frequency .......
82: High Efficiency Speaker Asylum, RE: Altec Model 19 Empty Cabinets - What Would You Do? (0.00)
Posted by DanK tubes on 2012-05-30, 10:04:05 (199.255.44.5)
I would go with new GPA drivers (902-8a and GPA 416-8c) and vintage 811b horns with the late great Zilch's Z19 crossover (1200Hz). Dan .......
83: High Efficiency Speaker Asylum, RE: Altec 511b/416 crossover? (0.00)
Posted by DanK tubes on 2012-05-17, 11:13:36 (199.255.44.5)
Thanks Kyle. I'm using flea powered SET amps so figured that was OK for the 902. Dan .......
84: High Efficiency Speaker Asylum, Altec 511b/416 crossover? (0.00)
Posted by DanK tubes on 2012-05-17, 08:19:10 (199.255.44.5)
I'm thinking of putting together a new HE speaker setup using Altec 511b horns with GPA 902-8a drivers, and GPA 416-8c drivers mounted in 10 cuft MLTL corner cabinets. I'm thinking of crossing them at .......
85: Tube DIY Asylum, RE: A few conservative design hints (0.00)
Posted by DanK tubes on 2012-04-12, 14:16:07 (199.255.44.5)
Don't see why it's such a silly question. Personally I think it's wrong for you to promote the virtues of low DCR inductors (day after day), given the fact that you are a manufacturer of low DCR induc .......
86: Tube DIY Asylum, RE: A few conservative design hints (0.00)
Posted by DanK tubes on 2012-04-12, 12:51:41 (199.255.44.5)
I bet if you looked inside one you would find some of the inductors that Jeff is building and selling. I suspect his filling the forum with propaganda is just a way for him to advertise and sell more .......
87: Tube DIY Asylum, thanks Lew! (nt) (0.00)
Posted by DanK tubes on 2012-04-06, 15:00:28 (199.255.44.5)
nt .......
88: Tube DIY Asylum, RE: Wow, strangely how we're converging to these things now. Deja vu all over again! (0.00)
Posted by DanK tubes on 2012-04-04, 16:55:13 (199.255.44.5)
I also don't mind sand in my amps, but am curious about your comments. Why did you (and dt667 too) suggest a tube input and solid state output? What about solid state driver and tube output stage? Spe .......
89: Tube DIY Asylum, half a mind? (0.00)
Posted by DanK tubes on 2012-04-03, 23:05:15 (63.249.110.86)
"If you think about it with half a mind, he is discussing just a LOW current supply !! Like screens on his 813 amp, or a preamp. NOT finals of a power amp." Can't you read Jeff? Maybe you just didn't .......
90: Tube DIY Asylum, here here! (0.00)
Posted by DanK tubes on 2012-04-03, 15:43:02 (199.255.44.5)
Thanks for sharing Henry! I'm actually collecting parts for Gary Pimm's Solid State Tabor amp. It's a ways off, but I hope to share it here when I'm done. Dan .......
91: Tube DIY Asylum, RE: No inconsistancies at all... (0.00)
Posted by DanK tubes on 2012-04-03, 12:56:00 (199.255.44.5)
Jeff, You didn't answer my last question. Let's see if you can answer this one. How do you quantify Superior? Can you give me any specs on your power supply (two 5V3s, L1 of 35 mHY, C1 of 15 or 20 uF, .......
92: Tube DIY Asylum, RE: No inconsistancies at all... (0.00)
Posted by DanK tubes on 2012-04-02, 19:39:09 (63.249.110.86)
I do not think that your specific recipe (two 5V3s, L1 of 35 mHY, C1 of 15 or 20 uF, L2 of 2 to 2.2 Hy at 7 Ohms, and C2 of 47 to 56 uF) is a new set of ideas. And I know it does not provide superior .......
93: Tube DIY Asylum, RE: No inconsistancies at all... (0.00)
Posted by DanK tubes on 2012-04-02, 13:21:50 (199.255.44.5)
Uggg, there is no hope. I guess that's whey the call it the asylum. "I would be happy to send you, or anyone else, my JLH and Swenson Forum posting compliations" No thanks. I'm not interested. I pre .......
94: Tube DIY Asylum, RE: new project: Eli Duttman MOSFET RCA Phono (0.00)
Posted by DanK tubes on 2012-04-01, 16:22:01 (63.249.110.86)
The MOSFET is a three terminal device. The data sheet will have the three terminals labeled D (Drain), G (Gate), and S (Source). In this schematic, the 125k ohm resistor is connected to the Source, th .......
95: Tube DIY Asylum, ooops (0.00)
Posted by DanK tubes on 2012-03-31, 17:45:25 (63.249.110.86)
I stand corrected. CV4035 is what I'm using. Dan .......
96: Vintage Asylum, RE: Schematic for Ampex 6873 monoblocks (0.00)
Posted by DanK tubes on 2012-03-29, 08:55:51 (63.249.110.86)
Sure thing Henry. Email sent with schematics and details. Dan .......
97: Vintage Asylum, RE: Schematic for Ampex 6873 monoblocks (0.00)
Posted by DanK tubes on 2012-03-28, 13:20:52 (199.255.44.5)
I can email you a copy if you still need it. I've got a pair I restored. They are amazing amps. Dan .......
98: Tube DIY Asylum, RE: An Infinity Sampling Rate is....ANALOGUE !! (0.00)
Posted by DanK tubes on 2012-03-27, 10:46:53 (199.255.44.5)
Jeff, I see some inconsistencies in your arguments here. On the one side, you are stating that the signal from a 106 piece orchestra is very complex and extremely difficult to reproduce. But at the sa .......
99: Tube DIY Asylum, RE: new project: Eli Duttman MOSFET RCA Phono (0.00)
Posted by DanK tubes on 2012-03-26, 13:21:16 (199.255.44.5)
Thanks rdf. Yes that is a un-etched copper circuit board and it is grounded. The only caps that are directly mounted to the board are the MBGO PIO caps. Guess I can test them with my capacitance meter .......
100: Tube DIY Asylum, RE: new project: Eli Duttman MOSFET RCA Phono (0.00)
Posted by DanK tubes on 2012-03-26, 13:17:19 (199.255.44.5)
"I also assume the CV4034 was a typo as the Brimar 12AX7 = CV4004." The Brimar CV4034 is a flying lead version of the CV4004. It's suppose to be the same tube. Tubemonger has the tooling to install ph .......
101: Tube DIY Asylum, RE: new project: Eli Duttman MOSFET RCA Phono (0.00)
Posted by DanK tubes on 2012-03-25, 23:28:06 (63.249.110.86)
Thanks Jeff. It is a pretty big chassis (12"x17"x3.5"). I do research for a hard drive company and scrounge a lot of cool stuff by dumpster diving at the lab. That box was built for the recording phys .......
102: Tube DIY Asylum, RE: Nice......... (0.00)
Posted by DanK tubes on 2012-03-25, 23:09:44 (63.249.110.86)
Thanks Neff. Please let us know how you think the JE Labs project compares. As for the Brimar CV4004's, it's such a new amp it's hard to make a final call on the sound, but I like what I hear so far. .......
103: Tube DIY Asylum, new project: Eli Duttman MOSFET RCA Phono (0.00)
Posted by DanK tubes on 2012-03-25, 10:20:12 (63.249.110.86)
A while back a built up Eli's RCA style 12ax7 phono stage. My first version was mostly a junk box project. I really liked what I heard so I decided to build another version of it with better layout an .......
104: Tube DIY Asylum, RE: Yes I covered Fourier in my 'mid-life crisis degree' (0.00)
Posted by DanK tubes on 2012-03-21, 12:42:12 (199.255.44.5)
Wow, he scoffed at a historically famous mathmatician/physicist who's work from 200 years ago is so important that it is still used on a daily basis by scientists and engineers. This Bob Fulton must b .......
105: Tube DIY Asylum, RE: 12by7 drive 45 schematic (0.00)
Posted by DanK tubes on 2012-03-14, 22:37:01 (63.249.110.86)
Thanks for brining that up. I've heard some people say the same thing, but I;m not sure why. I think that with a high enough inductance it should be fine, and the BCP-16 Ni should be a few thousand H. .......
106: Tube DIY Asylum, RE: 12by7 drive 45 schematic (0.00)
Posted by DanK tubes on 2012-03-14, 22:33:03 (63.249.110.86)
Hi Jim, Thanks for pointing out the voltages. I knew they were 220 and 170, but I thought they were the other way around. Like I said, I'm new to pentodes, but reading up on them made me think it was .......
107: Tube DIY Asylum, OK, will add regulation (0.00)
Posted by DanK tubes on 2012-03-14, 22:22:45 (63.249.110.86)
Thanks for the tips Eli and 3db. Looks like adding a screen regulator won't be too much work. I'm really starting to like the Supratex corporation. Eli, yes I realize that 12by7s are getting scarce. .......
108: Tube DIY Asylum, thanks Dave (nt) (0.00)
Posted by DanK tubes on 2012-03-14, 22:16:54 (63.249.110.86)
nt .......
109: Tube DIY Asylum, 12by7 drive 45 schematic (0.00)
Posted by DanK tubes on 2012-03-14, 17:29:47 (199.255.44.5)
About a year ago I built up some 417a/45 amps based on design specs Gordon Rankin posted up here. After listening to the amps for a while I think I want to tinker with them. The sound is really detail .......
110: Tube DIY Asylum, Thanks everyone (0.00)
Posted by DanK tubes on 2012-03-07, 13:06:12 (199.255.44.5)
I've used capacitive impedance (along with a small fuseable resistor) to drop 120VAC down to an acceptable level for an LED driver. That little LED driver is still working after a year, but I realize .......
111: Tube DIY Asylum, dropping AC voltage with a capacitor (0.00)
Posted by DanK tubes on 2012-03-06, 13:51:18 (199.255.44.5)
Hi All. I have power transformer with a 20Vrms tap that I would like to use as the input for a regulated 6.3Vdc heater supply. I'm supplying DC to two 12ax7 tubes, 1.2A total current. I don't want th .......
112: Tube DIY Asylum, Good old Dr. Leach (0.00)
Posted by DanK tubes on 2012-03-02, 09:20:35 (199.255.44.5)
Had him for some circuits classes, and Eugene Patronis for electro acoustics in the physics dept. Great guys! Dan .......
113: Tube DIY Asylum, Thanks everyone! (0.00)
Posted by DanK tubes on 2012-02-13, 14:27:11 (199.255.44.5)
Figured I came to the right place. Dan .......
114: Tube DIY Asylum, RE: CCS for a source follower? (0.00)
Posted by DanK tubes on 2012-02-13, 13:32:46 (199.255.44.5)
Hi Eli. I figured the 125k resistor was to keep the disipation within limits. I started thinking about this MOSFET source follower stage after reading over Tre's post regarding driver impedence and .......
115: Tube DIY Asylum, CCS for a source follower? (0.00)
Posted by DanK tubes on 2012-02-13, 12:20:20 (199.255.44.5)
A while back I build Eli's modified RCA (12ax7) phono stage with MOSFET source follower ouput. It was a low budget project that I threw together, but it really impressed me. Now I'm building a nicer v .......
116: Vinyl Asylum, RE: ping Neff (0.00)
Posted by DanK tubes on 2012-02-10, 22:47:01 (63.249.110.86)
Thanks Neff. The first version of this circuit I built up using spare parts and a Bud box. I liked it so much I'm building another version with premium parts. I've got a pair of K&K cascade CCS boards .......
117: Vinyl Asylum, ping Neff (0.00)
Posted by DanK tubes on 2012-02-10, 16:04:56 (199.255.44.5)
Hi Neff, I'm also using Eli's RCA phono with MOSFET output. I'm interested in your CCS loading scheme. Can you contact me through inmate mail? Thanks, Dan .......
118: MagneQuest/Peerless Forum, RE: Ampex bridging input trafo (0.00)
Posted by DanK tubes on 2012-01-19, 07:31:34 (199.255.44.5)
The Ampex 4580200-01 is a balanced-bridging transformer with unit gain and a designed input impedance of 20K ohms. I have a pair of these that I wired up as a poor man's Magnequest Peerless Ingot pass .......
119: Tube DIY Asylum, Thanks Eli! (nt) (0.00)
Posted by DanK tubes on 2012-01-18, 19:49:58 (63.249.110.86)
nt .......
120: Tube DIY Asylum, RE: Why hybrid power supply?? (0.00)
Posted by DanK tubes on 2012-01-12, 07:42:26 (199.255.44.5)
Hi Eli, I was wondering if you could explain this for me. You stated: "Vacuum diodes switch faster than PN junction diodes. So, SS switching noise is blocked from entering the B+ rail" If the vacuum .......
121: Vinyl Asylum, Thanks Abe (0.00)
Posted by DanK tubes on 2011-12-23, 09:48:51 (173.8.157.165)
And thanks for the advice on plinths etc. Happy Holidays! Dan .......
122: Vinyl Asylum, RE: Beautiful! (0.00)
Posted by DanK tubes on 2011-12-22, 10:52:53 (63.249.110.86)
Hi Salectric, Jim is a regular seller over at audiogon, Jec965 is his name. If you do a search for "plinth" in the for sale listings you will pull up all his offerings. He also sells on ebay too. Dan .......
123: Vinyl Asylum, RE: 380 (0.00)
Posted by DanK tubes on 2011-12-22, 09:53:00 (63.249.110.86)
Hi j. I like the Stanton 380. Interstage Tranny turned me on to that one. It has a real lucius sound to it. The DL 103 has more detail and better soundstage, but the 380 is a sweet sounding cart. Give .......
124: Vinyl Asylum, RE: Its a beauty! (0.00)
Posted by DanK tubes on 2011-12-21, 16:17:33 (63.249.110.86)
Thanks. I was using a Fairchild 412. The Fairchild is also nice, and back in 1958 (the year my TD124 was built) they were both top of the line transcription decks. The Fairchild had an old, Empire arm .......
125: Vinyl Asylum, My rebuilt Thorens TD124 (0.00)
Posted by DanK tubes on 2011-12-21, 13:38:30 (63.249.110.86)
I recently had Jim Campbell rebuild my Thorens TD124. I was just spinning Monk and Coltrane, Live at Carnigie Hall, and was enjoying it so much, I just had to write up about it. I had him totally rebu .......
126: Tube DIY Asylum, RE: mystery audio transformers (0.00)
Posted by DanK tubes on 2011-12-20, 08:00:52 (199.255.44.5)
Hi Al, Didn't think of that. I was using an HP3324A, which has an output impedance of 50ohms. Outside of driving it with a tube, what's a good way to test the frequency response? Thanks, Dan ::: TOP .......
127: Tube DIY Asylum, mystery audio transformers (0.00)
Posted by DanK tubes on 2011-12-19, 14:10:32 (199.255.44.5)
While shopping at Nebraska Surplus Sales and wound up buying a pair of Autodyne Mfg (TA) A-130199-77 audio transformers. There are no specs there. But, $10 for a military spec audio transformer seemed .......
128: MagneQuest/Peerless Forum, RE: Large flat baffles (0.00)
Posted by DanK tubes on 2011-12-07, 19:54:30 (63.249.110.86)
Hi Mike, Joseph E. seems to have used that article to build his open baffles. This should be a good start for you. Dan .......
129: Tube DIY Asylum, Thanks Chris! nt (0.00)
Posted by DanK tubes on 2011-12-07, 12:44:36 (199.255.44.5)
nt .......
130: Tube DIY Asylum, G Pimm CCS MOSFET source? (0.00)
Posted by DanK tubes on 2011-12-06, 11:07:20 (199.255.44.5)
I was trying to buy parts to build up some of Gary Pimm's self bias CCS boards, but found that the Fairchild IRFS820B 500V 33W enhancement mode MOSFET is now obsolete and out of stock at Mouser. I loo .......
131: MagneQuest/Peerless Forum, Thanks Paul . NT (0.00)
Posted by DanK tubes on 2011-11-14, 10:53:42 (199.255.44.5)
nt .......
132: MagneQuest/Peerless Forum, RE: here is another one (0.00)
Posted by DanK tubes on 2011-11-11, 12:12:06 (199.255.44.5)
Hi Paul, I've been meaning to try this in a circuit myself. If you return the parafeed cap to the cathode, then the parafeed cap is in series with the cathode bypass cap. Does this effectively decreas .......
133: MagneQuest/Peerless Forum, RE: the plot thickens (0.00)
Posted by DanK tubes on 2011-10-26, 22:36:13 (63.249.110.86)
Hi keto, nice work. Just curious. How did you attach that big (oil maybe) cap to the top plate? Dan .......
134: Tube DIY Asylum, RE: one stage versus 2 stage driver (0.00)
Posted by DanK tubes on 2011-10-24, 22:22:34 (199.255.44.9)
Here is an interesting article Mike Lafevre posted up a while back that gives the argument for multiple low gain stages. It sounds like good advice to me. It's a great article for DIY folks in general .......
135: Tube DIY Asylum, RE: Baby Ongaku? (0.00)
Posted by DanK tubes on 2011-10-18, 15:19:53 (199.255.44.5)
Thanks Tre. :) I know people like silver coils, but sometimes the explainations for why they do seem a little kooky. Dan .......
136: Tube DIY Asylum, RE: Baby Ongaku? (0.00)
Posted by DanK tubes on 2011-10-18, 11:56:32 (199.255.44.5)
Hi Tre, I looked over the page. Any chance you can explain this quote for me: "Due to silver’s higher sensitivity to flux change (200%) it is able to reproduce lower level information produced by the .......
137: SET Asylum, RE: 40,000 tubes- Which Triodes for my 2A3 project? (0.00)
Posted by DanK tubes on 2011-09-21, 13:25:21 (199.255.44.5)
Some other not so obvious power tubes to look for include: 304TL/100TL/75TL Emiac tubes, VT52, and the VT-4/211. For small signal, try to find some WE437 tubes to use as a driver. Dan .......
138: Vintage Asylum, Lansing Iconic (0.00)
Posted by DanK tubes on 2011-09-18, 22:39:31 (63.249.110.86)
Even though there weren't many sold, I still always think of the Salon Iconic, from the late 30's, as the first true high fidelity home system. Rated at 40Hz to 10kHz, I suspect they still sound good .......
139: Tube DIY Asylum, RE: What filmcaps dit Allan Wright use (0.00)
Posted by DanK tubes on 2011-09-18, 21:53:28 (63.249.110.86)
I don't know from experience, but I read a lot of posts from him raving about Mundorf ZN caps. Suppose to be very neutral, and reasonably priced too. Dan .......
140: Tube DIY Asylum, RE: These are some of friend's radios,that he restored. (0.00)
Posted by DanK tubes on 2011-08-31, 16:08:40 (199.255.44.5)
Nice! Thanks for sharing. I always liked the old Zenith Robot Dials. It's a shame what happened to that company. Dan .......
141: Tube DIY Asylum, RE: Lets build us an amplitrex (0.00)
Posted by DanK tubes on 2011-08-17, 13:18:39 (199.255.44.5)
"I can't find the gas cap on my amp" Maybe it looks something like this: .......
142: Tube DIY Asylum, RE: Anyone have a simple shunt regulator for a small SE amp. (0.00)
Posted by DanK tubes on 2011-06-06, 19:14:18 (74.220.74.56)
Thanks TB. You should also read over Steve Bench's write up on regulators. A lot of good information there. Dan .......
143: Tube DIY Asylum, Burning Amp (0.00)
Posted by DanK tubes on 2011-06-06, 19:10:19 (74.220.74.56)
Not quite the trade show you are describing, but still a good DIY festival. Mostly attended by DIY Audio folks. Every October in San Francisco. Dan .......
144: Tube DIY Asylum, RE: Anyone have a simple shunt regulator for a small SE amp. (0.00)
Posted by DanK tubes on 2011-06-04, 10:01:43 (74.220.74.56)
Thorsten has a nice shunt regulator design for his universal amp. Here is a link (sorry there is a pop up with his web site). http://www.fortunecity.com/rivendell/xentar/1179/projects/legacy/Legacy.h .......
145: MagneQuest/Peerless Forum, RE: latest amp build (0.00)
Posted by DanK tubes on 2011-05-20, 22:41:29 (74.220.74.56)
Thanks Anand! With a 1v rms input, the output is about 2.5W. As quiet as they are I'll probably try them on headphones some time. Dan .......
146: MagneQuest/Peerless Forum, RE: more eyecandies ... my last DAC (0.00)
Posted by DanK tubes on 2011-05-09, 22:42:59 (74.220.74.56)
Hey Gianluca, is that the latest non-resonant, non-magnetic, non-conductive super chassis I've been hearing about? :) As long as it sounds good, that's all that matters in the end. Keep up the good .......
147: Tube DIY Asylum, RE: parallel feed (0.00)
Posted by DanK tubes on 2011-05-03, 13:38:49 (199.255.44.5)
Hi TDA, Lots of people have built parallel feed amps. There are even very sucessful comercial products with this circuit type. Take a look at the Bottlehead amps for example. I'm sure a quick search i .......
148: MagneQuest/Peerless Forum, RE: Bugle 45 - What is the Voltage for Power Transformer secondary (0.00)
Posted by DanK tubes on 2011-05-02, 11:58:20 (199.255.44.5)
Hi Andy, Make sure you read, and then reread, the Bugle article that Gordon has so graciously provided. All the info is there. Also, you can find the specs for the suggested MQ 5504 power transformer .......
149: MagneQuest/Peerless Forum, Amazing! (0.00)
Posted by DanK tubes on 2011-05-01, 20:19:38 (74.220.74.56)
I'm always amazed at what people can do with this hobby when they put there hearts into it. Really nice work TK! The sharp corners and no exposed screws makes them look so clean. Did you do the engrav .......
150: Tube DIY Asylum, Very Nice! (0.00)
Posted by DanK tubes on 2011-04-28, 13:58:16 (199.255.44.5)
It takes a lot of work to layout, bolt down, solder in and lace up all those parts into a small chassis. You did a beautiful job. Thanks for sharing. Dan .......
151: Vintage Asylum, RE: Or, you can find that 45 GeeTeeOh Tiger and give it a listen without driving... (0.00)
Posted by DanK tubes on 2011-04-22, 20:27:36 (74.220.74.56)
Too bad Lotus just ended production of the Elise. Super light performance cars are such fun to drive. .......
152: Vintage Asylum, oops your right (0.00)
Posted by DanK tubes on 2011-04-21, 19:05:29 (74.220.74.56)
punched in the wrong conversion 1W/.0013... .......
153: Vintage Asylum, RE: Can anyone find the error? nt (0.00)
Posted by DanK tubes on 2011-04-21, 15:22:28 (199.255.44.5)
Citation = 60W/$1500 --> $25/W --> $25/W *(1W/0.0806hp) = $310/hp Dan .......
154: MagneQuest/Peerless Forum, RE: latest amp build (0.00)
Posted by DanK tubes on 2011-04-18, 22:17:20 (74.220.74.56)
That's pretty slick. I guess that is the ultrapath connection, but with parallel feed. Correct me if I'm wrong, but with the way I have it, the 1500 ohm cathode R is in series with the DCR of the outp .......
155: MagneQuest/Peerless Forum, RE: latest amp build (0.00)
Posted by DanK tubes on 2011-04-18, 19:30:26 (74.220.74.56)
Thanks Tre', I'm always a fan of removing caps from a circuit, but maybe you can help understand this one. Wouldn't removing the 30uF cap increase cathode degeneration, decrease the gain, and increas .......
156: MagneQuest/Peerless Forum, RE: beaddifful! (0.00)
Posted by DanK tubes on 2011-04-17, 14:04:27 (74.220.74.56)
Thanks gianluca! Check out the Ultraperm shielding they have for sale at Electronic Goldmine. It's easy to cut and stick in place. I'll probably give LED bias a try for comparison. First I need to br .......
157: MagneQuest/Peerless Forum, RE: latest amp build (0.00)
Posted by DanK tubes on 2011-04-17, 10:35:23 (74.220.74.56)
Thanks for the kind words. I've always been impressed with the amps that you and Paul built. Maybe not the best venue for this, but here goes. I'm listening to these amps through some 10 cuft Mass Lo .......
158: MagneQuest/Peerless Forum, latest amp build (0.00)
Posted by DanK tubes on 2011-04-16, 21:28:53 (74.220.74.56)
Here is the latest project I have been working on. It's a pair of 417a/45 (or 483) monoblock amps. I thought people here might like to see them since they use a total of 10 MQ transformers (5 for each .......
159: Tube DIY Asylum, Thanks everyone! nt (0.00)
Posted by DanK tubes on 2011-04-15, 11:47:28 (199.255.44.5)
nt .......
160: Tube DIY Asylum, RE: LED driver suggestions (0.00)
Posted by DanK tubes on 2011-04-14, 09:49:59 (199.255.44.5)
OK. Yeah, in retrospect I should have used a lamp, but the amps are already assembled. The chassis is cut for an LED and I'd hate to take things apart to cut more metal for a lamp. Dan .......
161: Tube DIY Asylum, RE: LED driver suggestions (0.00)
Posted by DanK tubes on 2011-04-14, 09:21:38 (199.255.44.5)
Thanks for the input. Yes it is a tube amp. I do have a 6.3VAC tap for my input tube heater, 417a/5842. I was afraid to run an LED off of that for fear of injecting HF switching noise from the diodes .......
162: Tube DIY Asylum, LED driver suggestions (0.00)
Posted by DanK tubes on 2011-04-13, 22:56:36 (74.220.74.56)
Does anyone have a favorite way to drive an LED on/off indicator off of 120VAC? I had been using the driver in the link below but just smoked one. Always a shock to see smoke pouring out of an amp. Lu .......
163: MagneQuest/Peerless Forum, 1:1 B7 load impedence (0.00)
Posted by DanK tubes on 2011-04-11, 11:02:23 (199.255.44.5)
I have a nice pair of Ni B7 10k:10k transformers that I've been using on the input of some power amps for galvanic isolation. As it is now, I have the secondary loaded with a 10k pot. Problem is I hav .......
164: Tube DIY Asylum, RE: Lowering of line stage gain (0.00)
Posted by DanK tubes on 2011-03-29, 11:09:17 (199.255.44.5)
Hum could be from a ground loop between stages. You could add in a 1:1 transformer for galvanic isolation to see if that stops it. Dan .......
165: Tube DIY Asylum, RE: Thanks for all the respoinses to my regulator posting!!!! (0.00)
Posted by DanK tubes on 2011-03-25, 16:08:16 (199.255.44.5)
Most people tend to shy away from both solid state and series regulators, however I think they can be great. At least my experience with the Swenson/Pimm series regulator has been great. John Swenson .......
166: Tube DIY Asylum, RE: I don't know Lew...... (0.00)
Posted by DanK tubes on 2011-03-08, 16:57:29 (199.255.44.5)
"I have no such formal training" So you are not actually a Dr? Just currious, if you oppose formal eudcation, why did you pick a moniker with Dr in it? .......
167: Tube DIY Asylum, RE: Allen Wright passes (0.00)
Posted by DanK tubes on 2011-03-01, 11:50:17 (199.255.44.5)
What sad news. He was so knowledgeable and helpful. I freqently find myself searching through old posts of his. The asylum was so lucky to have him. He will be missed greatly. Dan .......
168: Tube DIY Asylum, RE: Grid choke and pentode drivers (0.00)
Posted by DanK tubes on 2011-02-23, 10:26:24 (199.255.44.5)
DanL is right, best for grid chokes. However, one thing you should probably check is the max operating voltage. I know that Magnequest has several versions of grid chokes, and their high Ni grid choke .......
169: MagneQuest/Peerless Forum, RE: how about a gyrator as an active load? (0.00)
Posted by DanK tubes on 2011-02-14, 22:38:46 (74.220.74.160)
Hi Tim, Interesting idea, but I'm still trying to wrap my head around it. That's quite a long thread over on DIY Audio. In Gianluca's example, a 45 parafeed SET with a CCS active load would require a .......
170: MagneQuest/Peerless Forum, Thanks everyone! (0.00)
Posted by DanK tubes on 2011-02-13, 14:37:32 (74.220.74.160)
Great comments. Sounds like it's worth experimenting with, if I can get my B+ up high enough. Dan .......
171: MagneQuest/Peerless Forum, active loading with parallel feed? (0.00)
Posted by DanK tubes on 2011-02-12, 21:59:00 (74.220.74.160)
I've been looking over Gary Pimm's article on active loads for tubes, and saw his example of CCS loading on an output stage (see link). He uses a CCS above the plate on the output tube to handle the D .......
172: Vintage Asylum, vintage collection on craigslist (0.00)
Posted by DanK tubes on 2011-02-11, 06:47:17 (74.220.74.160)
Check out the collection that this guy has for sale in Lincoln CA. Pretty amazing stuff. I was looking at the Stevens Tru Sonic and was surprised at how close it looks to an Altec 612 cabinet. I'm no .......
173: Tube DIY Asylum, RE: Anyone familiar with this amp from RCA (0.00)
Posted by DanK tubes on 2011-02-09, 21:10:54 (74.220.74.160)
A Berkshire set! Wow, that's high end stuff. Made to compete with E. H. Scott. I guess the article says it all. I always keep my eye out for those, and would love to have one of the modern cabinets. I .......
174: MagneQuest/Peerless Forum, Not so unobtainium (0.00)
Posted by DanK tubes on 2011-02-05, 17:26:19 (74.220.74.160)
Hey Bas, There's been a pair of TL404 autoformers for sale on the Audio Asylum classifieds for a month or so. They are calling my name, but I just have too many other projects in the works. If I was m .......
175: MagneQuest/Peerless Forum, RE: Please recommend a Parafeed 45 project (0.00)
Posted by DanK tubes on 2011-02-03, 22:54:39 (74.220.74.160)
As Mike pointed out, the Bugle 45 is a great place to start. I built a pair of these that I still listen to on a daily basis. A really great design. Thanks Gordon! It should be easy to convert to para .......
176: MagneQuest/Peerless Forum, Robin Hood PF (0.00)
Posted by DanK tubes on 2011-02-03, 22:41:09 (74.220.74.160)
Just curious, aside from the bell ends and primary impedance, how close is the RH-PF design to the TFA-2004 Jr? Thanks, Dan .......
177: Tube DIY Asylum, RE: Upgrade steps (0.00)
Posted by DanK tubes on 2011-01-27, 20:50:56 (74.220.74.160)
Ahhh, late 60's Roadrunners are some of my favorite Mopars. How could you move on to a Chevelle? Still miss my 72 Cuda. Dan .......
178: Tube DIY Asylum, RE: Umbilical cord and grounding (0.00)
Posted by DanK tubes on 2011-01-26, 21:33:25 (74.220.74.160)
Wow! What a great write up and contribution to the DIY community. Thanks Dave. Dan .......
179: Tube DIY Asylum, RE: Umbilical cord and grounding (0.00)
Posted by DanK tubes on 2011-01-25, 15:48:00 (199.255.44.5)
Hi Thomas, what do you think about ground loop breakers (see link). I was thinking of adding these at each chassis ground point. Thanks, Dan .......
180: Tube DIY Asylum, Good point. Thanks (nt) (0.00)
Posted by DanK tubes on 2011-01-25, 14:13:42 (199.255.44.5)
nt .......
181: Tube DIY Asylum, RE: Copper sheets (0.00)
Posted by DanK tubes on 2011-01-25, 14:11:35 (199.255.44.5)
I've seen Pete Millett use that approach with copper clad FR4. Take a look at the link. He solders ground points where ever needed. His claim is that it works great and he likes to build all his amps .......
182: Tube DIY Asylum, Umbilical cord and grounding (0.00)
Posted by DanK tubes on 2011-01-25, 11:29:07 (199.255.44.5)
I'm working on a preamp with an outboard power supply connected with an umbilical cord. Normally I like star grounding with a single connection to the chassis. I'm planning out these connections now w .......
183: Tube DIY Asylum, RE: Stacked SiC diodes (0.00)
Posted by DanK tubes on 2011-01-13, 21:00:24 (74.220.74.38)
Cool idea! At 12 bucks a pop for 1200V PIV SiC, this is cost effective and looks pretty bullet proof. Thanks Eli, Dan .......
184: Tube DIY Asylum, Stacked SiC diodes (0.00)
Posted by DanK tubes on 2011-01-13, 17:00:36 (199.255.44.5)
I've read that Cree does not recommend stacking their 600V, 3A, SiC diodes (I'm not sure why). I have some Infineon Technologies IDT02S60C600V, 3A, SiC diodes and their datasheet does not mention a pr .......
185: MagneQuest/Peerless Forum, email sent (0.00)
Posted by DanK tubes on 2011-01-03, 20:23:32 (74.220.74.38)
Thanks Kevin! Dan .......
186: Tube DIY Asylum, ZVN0545a cascode? (0.00)
Posted by DanK tubes on 2010-12-25, 15:01:27 (74.220.74.250)
Happy holidays everybody! I've been running a phono stage that I built using Eli D.'s modified RCA (12ax7) design. The output for this is a ZVN0545a FET. It's a great phono stage, but I always like to .......
187: Tube DIY Asylum, RE: Where can I buy these heatsinks.......see picture. (0.00)
Posted by DanK tubes on 2010-12-24, 08:19:49 (74.220.74.38)
You can buy them from typical parts houses (Mouser, Digikey, etc.), you just need to know the transistor package size. In a pinch, I've made my own. Just use some tin snips to cut up an aluminum can. .......
188: Tube DIY Asylum, RE: PM sent (0.00)
Posted by DanK tubes on 2010-12-17, 16:27:45 (199.255.44.5)
OK, just send me an inmate mail and I'll email it to you. Ampex used Triad iron, and I suspect that has a lot to do with their nice sound. Dan .......
189: Tube DIY Asylum, PM sent (0.00)
Posted by DanK tubes on 2010-12-16, 21:55:20 (74.220.74.38)
Hi Eeehaah, I have a copy of the Ampex 6973 schematic that I can email you. I have the amps too, and can assure you that it is an excellent design. Dan .......
190: SET Asylum, RE: 2a3 replace with 45 (0.00)
Posted by DanK tubes on 2010-12-14, 21:37:34 (74.220.74.38)
Hi Paul, Thats an interesting plot. The 2nd and 3rd order harmonics scale together with the load. I can't find the original post, but here is a link to one from Mike regarding the 2A3. In this case, i .......
191: SET Asylum, RE: 2a3 replace with 45 (0.00)
Posted by DanK tubes on 2010-12-13, 22:47:29 (74.220.74.38)
Hi Paul, Thanks for the suggested operating point. Its interesting that a lower plate voltage works better into a lower impedence load. I remember Larry and Gordon talking about 10 operating points, a .......
192: Tube DIY Asylum, RE: do we really need to care about the square wave ? or sine wave is fine and good enough? (0.00)
Posted by DanK tubes on 2010-12-13, 13:30:24 (199.255.44.5)
No problem. Yeah, that is a nice series. A lot of folks here aren't interested in math or measurements. I like to look at measurements and listen to the sound. It's kind of like reading the New York T .......
193: Tube DIY Asylum, RE: do we really need to care about the square wave ? or sine wave is fine and good enough? (0.00)
Posted by DanK tubes on 2010-12-12, 22:32:40 (74.220.74.38)
There was a nice article in EE Times regarding speakers, amps and cables. It has a good argument in there for improving the response to a heavyside function (part 3). That said, I'm sure a nice square .......
194: Tube DIY Asylum, RE: This may be far fetched but strange things happen.. (0.00)
Posted by DanK tubes on 2010-12-02, 05:59:42 (74.220.74.38)
Hi Mike, For transformer data, both Bunkerofdoom xfm and Pete Millet's site are usually pretty good. But in this case they don't have anything from Freed. I know that Mike at Magnetquest has an archiv .......
195: Tube DIY Asylum, RE: OT: Happy Loy Krathong from Chiang Mai, Thailand! (0.00)
Posted by DanK tubes on 2010-11-23, 21:03:21 (74.220.74.38)
Wow, I hope Loy Krathong was safe for you. That was a sad story out of Cambodia. Dan .......
196: Tube DIY Asylum, 100uF 63VDC (0.00)
Posted by DanK tubes on 2010-11-23, 20:59:19 (74.220.74.38)
Digikey also has these Epcos 100uF, 63VDC, MKT caps. I haven't tried them but I suspect even polyester will sound better than electrolytics. Dan .......
197: Tubes Asylum, Tube ornaments (0.00)
Posted by DanK tubes on 2010-11-22, 19:35:48 (74.220.74.38)
I hope this guy is using duds. Dan no affiliation, just thought it was funny. .......
198: Tube DIY Asylum, Thanks Dan! nt (0.00)
Posted by DanK tubes on 2010-11-12, 11:42:28 (199.255.44.5)
nt .......
199: Tube DIY Asylum, RE: What type of signal cable/wire do you use in your builds? (0.00)
Posted by DanK tubes on 2010-11-11, 17:30:12 (74.220.74.38)
Hi Kurt, Do you have a part number for the solid core teflon type? The last two (cat5 and cat6) cables I've cut open turned out to be standed PVC. It's hard to tell from the Radio Shack descriptions o .......
200: Tube DIY Asylum, RE: 417a Grid stopper primer needed! (0.00)
Posted by DanK tubes on 2010-11-10, 22:35:34 (74.220.74.38)
Hi Dan, Nice looking tube. Now I see why Arthur Loesch uses them in his phono stage. What's your favorite operating point? Is there any difference between the 6GK5 and the 6FQ5? Thanks, Dan ::: TOPIC .......
201: Tube DIY Asylum, RE: Explanation (0.00)
Posted by DanK tubes on 2010-09-30, 13:24:21 (199.255.44.5)
Hi Henry, Thank you for the explaination. Very interesting! I need some time to fully wrap my brain around it. Dan .......
202: Tube DIY Asylum, RE: Explanation (0.00)
Posted by DanK tubes on 2010-09-30, 07:56:49 (199.255.44.5)
Hi Henry, Your circuit in simulation shows a sub-critical inductance choke input with a pi filter after it. So it's approximately just a pi filter. A pi filter with a 395V RMS transformer should push .......
203: Tube DIY Asylum, RE: Explanation (0.00)
Posted by DanK tubes on 2010-09-30, 06:20:10 (74.220.74.38)
Hi Henry, In your post you stated: "The effect of the inductor, in the electromechanical analog, is to impart additional "momentum" to the charging current pulses, hence the term "flywheel." With the .......
204: Tube DIY Asylum, noise reduction (0.00)
Posted by DanK tubes on 2010-09-24, 08:38:44 (199.255.44.5)
Hi Neff, You mentioned these can help with noise reduction. With solid state rectification for B+ people often put a cap or cap/resistor across the secondary to reduce switching noise. Could this also .......
205: Tube DIY Asylum, RE: What's the function of 2 ceramic disk .01uf caps aross the legs of the main power line before the transformer? (0.00)
Posted by DanK tubes on 2010-09-24, 06:58:22 (74.220.74.38)
What kind of equipment are the caps on? This is pretty standard on old radios. It provides a virtual ground for RF. Dan .......
206: MagneQuest/Peerless Forum, RE: help me. i misplaced a schematic. exo173 (0.00)
Posted by DanK tubes on 2010-09-22, 22:06:25 (74.220.74.38)
Yeah, I wish I had access to their other manuals. I tried searching that web site on the internet archive I didn't get much either. It seems you need to pay for access. But for some reason I can still .......
207: Tube DIY Asylum, RE: do you mean 2 tubes per channel? (0.00)
Posted by DanK tubes on 2010-09-22, 13:08:38 (199.255.44.5)
Just to play the devil's advocate... How about an output tube with two sections? The 6BX7 comes to mind. As badman pointed out you can build two stage spud amps with one tube per channel using tubes .......
208: MagneQuest/Peerless Forum, RE: help me. i misplaced a schematic. exo173 (0.00)
Posted by DanK tubes on 2010-09-22, 06:56:55 (74.220.74.38)
Hi Gianluca, There are a bunch of old Altec schematics here, including a PP845 but I'm not sure if it's what you wanted. Good reading none the less. Dan .......
209: Tube DIY Asylum, Thanks Hakan (0.00)
Posted by DanK tubes on 2010-09-18, 21:16:50 (74.220.74.38)
Nice review. I'll have to pick some of those up to try out. Dan .......
210: Tube DIY Asylum, RE: There are two caps I really fell in love with that are stunners. (0.00)
Posted by DanK tubes on 2010-09-17, 23:20:35 (74.220.74.38)
Hey Mike, Have you ever tried these silver mica caps? They are a little bit larger value (0.1264uF), but have a lower voltage rating and larger tolerance. Dan .......
211: Tube DIY Asylum, RE: UTC tranny q's? (0.00)
Posted by DanK tubes on 2010-09-10, 20:48:20 (74.220.74.38)
You could check here. Dan .......
212: Tube DIY Asylum, RE: rough numbers (0.00)
Posted by DanK tubes on 2010-09-03, 21:09:06 (74.220.74.38)
Thanks Tre'! This has really been a great thread. Dan .......
213: Tube DIY Asylum, RE: rough numbers (0.00)
Posted by DanK tubes on 2010-09-03, 14:59:40 (199.255.44.5)
It's Grodon't design, I just tweeked it. I have a 6BY5 dual damper diode rectifier and use a 220uF Panasonic TSHA cap. Here is the link. Dan .......
214: Tube DIY Asylum, RE: rough numbers (0.00)
Posted by DanK tubes on 2010-09-03, 13:52:19 (199.255.44.5)
"Yes, the power supply supplies DC and the load draws only DC from the power supply and the last cap bypasses short term current draw changes in the circuit (the music, if you will). Just lik .......
215: Tube DIY Asylum, rough numbers (0.00)
Posted by DanK tubes on 2010-09-03, 09:23:04 (199.255.44.5)
Thanks Tre, In the Bugle circuit, the output impedence is 5k. The power supply actually feeds both the driver and the output tubes in parallel. I'm not sure what the impedence of the SRPP 12ay7 is, b .......
216: Tube DIY Asylum, RE: RC PS filter (0.00)
Posted by DanK tubes on 2010-09-02, 12:40:35 (199.255.44.5)
Hi Jeff, For PSUDII modeling, I've been following the procedure that DHTRob/Bas wrote up in their article (see link). I haven't done any current step testing. I would like to see your procedure for th .......
217: Tubes Asylum, wafer thin brushes (nt) (0.00)
Posted by DanK tubes on 2010-09-02, 11:48:55 (199.255.44.5)
nt .......
218: Tube DIY Asylum, RE: RC PS filter (0.00)
Posted by DanK tubes on 2010-09-01, 16:33:05 (199.255.44.5)
Hi Al, The power supply is based on Gordon Rankin's Bugle design with older Stancor iron: 700VCT transformer, 6BY5 dual damper diodes, 0.82uF/30H/220uF filter, to generate ~335VDC at ~40mA for a 45 am .......
219: Tube DIY Asylum, RC PS filter (0.00)
Posted by DanK tubes on 2010-09-01, 13:31:24 (199.255.44.5)
I have a choke input cRC filter and the C is a 220uF Panasonic TSHA electrolytic. Everyone seems to think the ASC oil caps sound great, so I would like to add one of these, 15uF, at the end of my powe .......
220: High Efficiency Speaker Asylum, RE: Channel unbalance... (0.00)
Posted by DanK tubes on 2010-08-31, 13:08:32 (199.255.44.5)
The first thing I would do is swap the cable inputs from L to R at each point: source, pre amp, or power amp, speakers. That should help you find where the problem is coming from. Good luck, Dan ::: .......
221: Tube DIY Asylum, RE: MKT nt (0.00)
Posted by DanK tubes on 2010-08-26, 21:08:42 (74.220.74.38)
Yeah, that looks better. thanks. Dan .......
222: Tube DIY Asylum, Epcos MPK for cathode bypass? (0.00)
Posted by DanK tubes on 2010-08-25, 12:14:15 (199.255.44.5)
Has anyone tried these Epcos 100uF 63VDC MPK caps (see link) for cathode bypass? They look pretty large but I have some space. I've been looking for a good alternative to electrolytics for cathode byp .......
223: Vintage Asylum, RE: FM-3 part deux (0.00)
Posted by DanK tubes on 2010-08-10, 22:38:14 (74.220.74.38)
Hey Vinnie, Don't give in, you can do it! I recently did an alignment on a E. H. Scott 800b. In the past I had followed alignment procedures for radios but never got them perfect. The Scott was way to .......
224: High Efficiency Speaker Asylum, RE: 604 alnico vs 604 ferrite (0.00)
Posted by DanK tubes on 2010-08-10, 21:59:03 (74.220.74.38)
There shouldn't be any difference. I've had 604Cs and 604-8Ks and I'm with Tom, the sound on newer versions is a lot different because of the tangerine phase plugs and mantaray horns. Better to my ear .......
225: Tube DIY Asylum, RE: Phono stage.... (0.00)
Posted by DanK tubes on 2010-07-26, 21:10:47 (74.220.74.38)
1.5k! Sweet. Thanks Dan. I've been really happy with Eli's modified RCA, but Thorsten's design keeps tempting me. Dan .......
226: Tube DIY Asylum, RE: Phono stage.... (0.00)
Posted by DanK tubes on 2010-07-26, 16:26:51 (199.255.44.5)
Thorsten's LCR RIAA gets a lot of good praise. Do you know what it's output impedence is? Dan .......
227: Vinyl Asylum, RE: Thorens Plinth Long (0.00)
Posted by DanK tubes on 2010-07-25, 22:22:22 (74.220.74.38)
Nice plinth! This gives me some inspiration to build one for mine. Is the problem with the power cable? Dan .......
228: Tube DIY Asylum, RE: Dan (0.00)
Posted by DanK tubes on 2010-07-23, 07:03:40 (74.220.74.38)
OK, so now it's totally clear that you have given your own definition to the term transfer function and you have made up the term transfer efficiency. In this case, both of these are just a way for yo .......
229: Tube DIY Asylum, RE: Dan (0.00)
Posted by DanK tubes on 2010-07-22, 13:44:16 (199.255.44.5)
Hi Jeff, I think we may be saying the same thing. Here is a little more on the standard definition of transfer function. A transfer function can be measured for electrical components. It is a plot of .......
230: Vinyl Asylum, RE: SUT loading calculator. (0.00)
Posted by DanK tubes on 2010-07-22, 07:02:35 (74.220.74.38)
Thanks for putting this together Dave. Reading over old posts I was under the impression you favored secondary loading. What changed your mind? Dan .......
231: Tube DIY Asylum, Great quote! (0.00)
Posted by DanK tubes on 2010-07-21, 21:44:13 (74.220.74.38)
he he I need to remember that one. sometimes I feel that way about my projects. Dan .......
232: Tube DIY Asylum, RE: drlowmu: Self lead-outs of transformers and transfer efficiency. (0.00)
Posted by DanK tubes on 2010-07-21, 11:59:54 (199.255.44.5)
Jeff, Be carful when you use the term transfer funtion. A transfer function is a linear mapping of a Laplace transform or Fourier transform. I was under the impression you didn't believe in using Four .......
233: Tube DIY Asylum, RE: drlowmu: Self lead-outs of transformers and transfer efficiency. (0.00)
Posted by DanK tubes on 2010-07-21, 11:28:56 (199.255.44.5)
I wonder what the units are for tansfer efficiency... BS/mm maybe? Dan .......
234: Tube DIY Asylum, RE: More on D3A ... (0.00)
Posted by DanK tubes on 2010-07-21, 06:59:53 (74.220.74.38)
On Pete Millett's web site there a ton of great info regarding high Gm tubes (see the link). Comparing the FFT of D3A (CCS triode, triode, and pentode modes) to the 6C45P, the D3A does has lower disto .......
235: MagneQuest/Peerless Forum, RE: Old transformer specs (0.00)
Posted by DanK tubes on 2010-07-18, 22:23:10 (74.220.74.38)
Hey Topper, Thanks for the input. The 289a does seem pretty strange. Here is a picture of showing part of the 19C oscillator schematic. The 289a input transformer is T2. The input side of the transfor .......
236: MagneQuest/Peerless Forum, looking up old transformer specs? (0.00)
Posted by DanK tubes on 2010-07-17, 22:25:55 (74.220.74.38)
Today I picked up some parts and projects at a ham fest including a potted ADC A8639 transformer and a Western Electric 19C oscillator that has some nice looking iron in there (WE 289a input transform .......
237: Tube DIY Asylum, ping wpod (0.00)
Posted by DanK tubes on 2010-07-17, 21:53:23 (74.220.74.38)
Hey wpod, can you send me an email, I have a question for you. Thanks, Dan .......
238: MagneQuest/Peerless Forum, Thanks guys (nt) (0.00)
Posted by DanK tubes on 2010-07-08, 15:44:18 (199.255.44.5)
nt. .......
239: Vintage Asylum, RE: another Craigslist post (Sacramento) (0.00)
Posted by DanK tubes on 2010-07-08, 14:20:15 (199.255.44.5)
"Did I see that these items were stored near the main reactor at Three Mile Island?" Oh yes, that is correct! If someone will send them my way I'll happily dispose of them. Dan .......
240: Vintage Asylum, another Craigslist post (Sacramento) (0.00)
Posted by DanK tubes on 2010-07-06, 20:59:18 (74.220.74.38)
I saw this one up on CL. Looks like some great stuff for all yous vintage guys in Sacramento. Wish I lived closer... I wonder ho much that Bose will go for? :P Dan (not affiliated, just passing on th .......
241: Tube DIY Asylum, RE: That's Good Info re: LCR-RIAA Circuit w/7788s (0.00)
Posted by DanK tubes on 2010-07-06, 16:26:08 (199.255.44.5)
Hey IT, any chance you can share your feedback eq circuit? Thanks, Dan .......
242: MagneQuest/Peerless Forum, RE: 10 output transformer? (0.00)
Posted by DanK tubes on 2010-07-05, 21:26:19 (74.220.74.38)
Hi Ed, Thanks for the input. I think Larry was advocating high plate voltage and high current to bring down the Rp. Sounds worthwhile, if I can just find some 7.5V filament transformers. Just curious .......
243: MagneQuest/Peerless Forum, 10 output transformer? (0.00)
Posted by DanK tubes on 2010-07-01, 22:24:07 (74.220.74.38)
Has anyone here tried loading a 10 with a 5k output transformer? I know that the 10 has an Rp of 5k, so a 5k load is far from ideal. I'm just looking for some thoughts before I give it a shot. Thanks .......
244: Tube DIY Asylum, good to know. (nt) (0.00)
Posted by DanK tubes on 2010-06-25, 18:48:10 (74.220.74.38)
nt .......
245: Tube DIY Asylum, RE: JJ versus CE Manufacturing multi section cap cans (0.00)
Posted by DanK tubes on 2010-06-25, 07:03:53 (74.220.74.38)
I did have a bad experience with the CE. I rebuilt a pair of Ampex 6973 monoblocks, swapped out all the caps, and used some CE 4 section, 500VDC caps for the power supply filter. The B+ is around 425V .......
246: Tube DIY Asylum, RE: Rectifier noise suppression (0.00)
Posted by DanK tubes on 2010-06-23, 13:17:39 (199.255.44.5)
Hi John, Thanks for the input. I've been wanting to use Jim's technique to determine the correct R and C for my power transformer, but I don't have a capacitance bridge for measurments. Your values wi .......
247: High Efficiency Speaker Asylum, RE: Does thickness of plywood affects the sound in any way? (0.00)
Posted by DanK tubes on 2010-06-12, 22:58:13 (74.220.74.38)
Not always the case. mechanical resonances, for the boards in a cabinet, are proportional to sqrt(k/m). Increasing the thickness increases the stiffness, but also the mass. That said, most people clai .......
248: High Efficiency Speaker Asylum, RCA field coil ID (0.00)
Posted by DanK tubes on 2010-06-06, 21:58:31 (74.220.74.38)
I've been thinking of picking up this old radio because of the speaker in there. I haven't seen it up close to get a part number off it, but can anyone ID the driver? It's a 15" RCA field coil unit. I .......
249: Tube DIY Asylum, Thanks Tom! (nt) (0.00)
Posted by DanK tubes on 2010-05-20, 06:47:50 (74.220.74.38)
nt .......
250: SET Asylum, RE: which Output transformer do deep bass (300b SET) (0.00)
Posted by DanK tubes on 2010-05-19, 22:31:06 (74.220.74.38)
Hi Paba, OK, it looks like you are testing the right things. If you can, hook up a function generator and oscilloscope to your amp and see how it looks driving a fixed load. Not exactly the same as ho .......
251: Tube DIY Asylum, RE: choke ratings question (0.00)
Posted by DanK tubes on 2010-05-19, 12:37:51 (12.133.178.5)
Hi Michael, "If they're rated for 2 volts AC at 1000 Hz, they will saturate at a much lower AC voltage at 50 or 60 Hz. It's not just the current that causes saturation; it's the integral of voltage, .......
252: SET Asylum, RE: which Output transformer do deep bass (300b SET) (0.00)
Posted by DanK tubes on 2010-05-19, 12:22:52 (12.133.178.5)
There are so many things that can contribute to the bass response. In a tube amp alone you have cathode bypass cap size (on input and driver stages), coupling cap size, etc. Then there is the speaker .......
253: Tube DIY Asylum, RE: choke ratings question (0.00)
Posted by DanK tubes on 2010-05-19, 09:50:30 (12.133.178.5)
Hi Tom, I do have a function generator, scope and extra chokes. What's the best way for me to go about testing? Thanks, Dan .......
254: Tube DIY Asylum, RE: choke ratings question (0.00)
Posted by DanK tubes on 2010-05-19, 09:37:05 (12.133.178.5)
Thanks for the input. They are ~1.5" x 1.5" x 2.5". Do you think they could be useful at blocking EMI/RFI? Dan .......
255: Tube DIY Asylum, choke ratings question (0.00)
Posted by DanK tubes on 2010-05-18, 22:26:55 (74.220.74.38)
I have some chokes that came out of a military surplus 60V power supply. The chokes are labeled: 0.050 H min 1000 CPS 1amp DC 2volt AC 100WV Do you guys think it would be a problem to run more than 2v .......
256: Tube DIY Asylum, RE: 1959 Ampex 6973 Monoblocks (0.00)
Posted by DanK tubes on 2010-04-29, 09:12:54 (12.133.178.5)
Nice score! Be careful using the 6CZ5. The schematic has 345V on the plate (B+ = 375), but when I measure mine the plate voltage is actually ~360V. That's OK for the 6973 since it is rated for a 440V .......
257: MagneQuest/Peerless Forum, RE: nice and simple... a universal template.... (0.00)
Posted by DanK tubes on 2010-04-02, 07:10:45 (74.220.74.38)
Ken Gilbert has the power supply for this amp shown on his web site. Looks like a nice an simple project. Dan .......
258: MagneQuest/Peerless Forum, Thanks Mike (nt) (0.00)
Posted by DanK tubes on 2010-04-02, 07:07:13 (74.220.74.38)
nt. .......
259: MagneQuest/Peerless Forum, RE: For Sale: RIT-5 airgapped IT (0.00)
Posted by DanK tubes on 2010-04-01, 20:45:07 (74.220.74.38)
Hi Mike, Could you make a version with a center tapped secondary for phase splitting? Or phase splitting better left to the EXO173? Dan .......
260: Tube DIY Asylum, RE: a Plate choke cheaper than CCS? (0.00)
Posted by DanK tubes on 2010-03-27, 22:59:33 (74.220.74.38)
Could you drop the voltage with a transistor and diode like they did in the link below? It might add some noise, but if you have a choke after it... Dan .......
261: Tube DIY Asylum, RE: Ipod and Tubes (0.00)
Posted by DanK tubes on 2010-03-25, 21:19:46 (74.220.74.38)
For a 50 year old piece, I would expect most all of the electrolytic and PIO caps would need to be swapped out. Here is a link to some basic info on the process of identification. Who knows you may ge .......
262: Tube DIY Asylum, RE: Ipod and Tubes (0.00)
Posted by DanK tubes on 2010-03-24, 12:56:11 (64.254.110.201)
You probably don't need to add a tube amp in there. My guess is it already has one. With out seening the unit you have I can oly take a guess at hooking it up. Probably the simplest way is to get a co .......
263: Tube DIY Asylum, Why? (0.00)
Posted by DanK tubes on 2010-03-17, 10:20:55 (64.254.110.201)
Just curious, why do you think the magnetic field doesn't extend so far? From the physics, both electric and magnetic fields from a wire drop off as 1/r. Ampere's law gives us B = u*I/2*pi*r Gauss's .......
264: Vintage Asylum, RE: For all of you responders do you use the built in (0.00)
Posted by DanK tubes on 2010-03-12, 12:44:07 (64.254.110.201)
Hi Eli, I hope I'm not hi-jacking the thread but, I built up this phono stage with a 180nF coupling cap and have been happy with it. How would switching to a 220nF cap effect the bass response? I migh .......
265: Tube DIY Asylum, RE: They only need to be parallel and adjacent (0.00)
Posted by DanK tubes on 2010-03-12, 06:55:44 (74.220.74.38)
Typical shielding would only block electric fields. Current induced magnetic fields, especially from filaments/heaters, would require a much different type of shielding. AFAIK, twisting is the easiest .......
266: MagneQuest/Peerless Forum, RE: russian caps codes (0.00)
Posted by DanK tubes on 2010-03-10, 22:41:12 (74.220.74.38)
I built a version of Gordon's Bugle 45 with RH-40 transformers that I like quite a lot. In those amps I did a direct comparison of Jensen PIO and the K409y for coupling duty. The K40 did have a funny .......
267: Vintage Asylum, 2nd the Markwart design (0.00)
Posted by DanK tubes on 2010-02-15, 22:23:01 (74.220.74.38)
604's are famous for problems around the crossover point that come from the spacial separation of the HF and LF drivers. URIE helped drive Altec out of business because they were the first to recogniz .......
268: Tube DIY Asylum, RE: Opinions on use of an OPT (40k:2k4) (0.00)
Posted by DanK tubes on 2010-01-29, 14:11:20 (64.254.110.201)
Probably a typo, but is the 2.2uF cap suppose to be tied to the grid? Dan .......
269: Tube DIY Asylum, RE: Eli's Phono Stage (0.00)
Posted by DanK tubes on 2010-01-28, 21:27:03 (74.220.74.38)
I've been testing out a lot of MM carts and the gain is high enough that I don't even need a preamp. I dropped my power amps input down to 10k ohms which is quieter, and the ZVN0545 has no trouble dri .......
270: Tube DIY Asylum, RE: Newbie phono stage (0.00)
Posted by DanK tubes on 2010-01-28, 21:15:01 (74.220.74.38)
Hi Eli, I wound up using a vintage Altec TP608A power transformer, mainly because I thought the metal case would keep some of the mag field away from my circuit. For the B+ I used UF4007's in a bridge .......
271: Tube DIY Asylum, RE: Newbie phono stage (0.00)
Posted by DanK tubes on 2010-01-28, 10:18:38 (64.254.110.201)
As the others have said, a phono stage is a difficult first project. They are so sensitive to grounding and parts layout/selection. I've been building projects for ~6 years now and still think I'm a n .......
272: Tube DIY Asylum, RE: ground loop isolators... (0.00)
Posted by DanK tubes on 2010-01-27, 22:33:09 (74.220.74.38)
I was having a similar problem between one of my 45 SET monoblocks and a phono stage. Disconnected, but turned on, and there was is no hum. But with an interconnect between the two, the amp starts hum .......
273: High Efficiency Speaker Asylum, Magnavox FC Power Dissipation (0.00)
Posted by DanK tubes on 2010-01-26, 12:44:38 (64.254.110.201)
I have a 15" Magnavox field coil speaker from the 40's and I'm trying to find out the max power dissipation. This one has a 675 ohm series field connection and a 9000 ohm shunt field connection. I've .......
274: Tube DIY Asylum, RE: B+ CT Standby Switch? (0.00)
Posted by DanK tubes on 2010-01-19, 20:01:07 (74.220.74.38)
Great ideas! Thanks a lot. Dan .......
275: Tube DIY Asylum, Kurt Strain used this (0.00)
Posted by DanK tubes on 2010-01-19, 11:09:06 (64.254.110.201)
on his Cobalt 45 amp (link below), that's what gave me the idea. But, I can see it being a shock for electronics. Thanks for the comments so far. I like Chris's partial B+ idea and think I'll give it .......
276: Tube DIY Asylum, B+ CT Standby Switch? (0.00)
Posted by DanK tubes on 2010-01-18, 14:19:25 (64.254.110.201)
I would like to use a standby switch on a power supply transformer, secondary side center tap. The switch would be between the CT and ground for a full wave rectifier. I've seen this done fairly often .......
277: Tube DIY Asylum, Thanks for the ideas (nt) (0.00)
Posted by DanK tubes on 2010-01-14, 08:41:35 (64.254.110.201)
nt. .......
278: Tube DIY Asylum, Mounting KBG caps? (0.00)
Posted by DanK tubes on 2010-01-13, 17:45:29 (64.254.110.201)
Does anyone know of mounting hardware for the large KBG PIO caps? To save space I'd like to mount these standing up on top of my next project. Below is the kind of package I'm talking about: Thanks, .......
279: Tube DIY Asylum, Caps for Mike Samra? (0.00)
Posted by DanK tubes on 2009-12-23, 13:49:04 (74.220.74.38)
240uF PIO looks like something Mike would dig. no affiliation, just thought they looked cool. Dan .......
280: Tube DIY Asylum, RE: Anyone built the Alan Kimmel OTL? (0.00)
Posted by DanK tubes on 2009-12-06, 22:54:03 (74.220.74.38)
No, I haven't built it, but is there any chance you can share the schematic? Thanks, Dan .......
281: High Efficiency Speaker Asylum, picture from the other side (0.00)
Posted by DanK tubes on 2009-11-08, 21:09:05 (74.220.74.38)
here it is .......
282: High Efficiency Speaker Asylum, Magnavox field coil coaxial? (0.00)
Posted by DanK tubes on 2009-11-08, 14:53:41 (74.220.74.38)
The other day I picked up a 1947 Scott Laboratories 800b console off of Craigslist for free. I still can't believe that one, but anyway... I was expecting the speaker to be a Jensen, but the EIA speak .......
283: High Efficiency Speaker Asylum, RE: So a stock N-1600 A is made for approxmately what size (0.00)
Posted by DanK tubes on 2009-10-20, 20:38:21 (74.220.74.38)
The 604/N-1600 used in thousands of Altec 612 studio monitors. These are around 4.5 ft^3 on the inside and are flat down to ~40 Hz (see link below). I have a pair of these and love them. The other com .......
284: Tube DIY Asylum, RE: Any San Francisco Bay Area DIYers attending "Burning Amp" tomorrow? (0.00)
Posted by DanK tubes on 2009-10-17, 20:06:32 (74.220.74.38)
No! I wish I had heard about it earlier, I could have planned for it. Do you know if there is a mailing list for future events? Dan .......
285: High Efficiency Speaker Asylum, what the heck... (0.00)
Posted by DanK tubes on 2009-10-15, 09:26:56 (64.254.110.201)
is that blue toy at the bottom of the pic? it kinda looks like one of those giant #1 hands you see at baseball games. great diy project. i bet my kids would like to build some of those. Dan ::: TOP .......
286: High Efficiency Speaker Asylum, RE: Altec 604C crossover upgrade (0.00)
Posted by DanK tubes on 2009-10-15, 08:57:08 (64.254.110.201)
No, when I bought my Altecs they didn't come with crossovers. So I can't directly compare the two. I do have a friend who also uses 604c's with the stock crossovers and I have listened to his system a .......
287: High Efficiency Speaker Asylum, RE: Altec 604C crossover upgrade (0.00)
Posted by DanK tubes on 2009-10-14, 22:57:38 (74.220.74.38)
If you feel like DIY, I highly recommend Jeff Markwart's phase corrected crossover. I built a pair of these for my 604c's. I used his plans for the 604b and it worked out great. The spacing between th .......
288: Vinyl Asylum, RE: Is this a crazy recommendation? (0.00)
Posted by DanK tubes on 2009-10-14, 16:17:48 (64.254.110.201)
Just curious, which Stanton/Pickering cart are you referring to? Dan .......
289: Vinyl Asylum, 2nd Ken Willis (0.00)
Posted by DanK tubes on 2009-10-12, 14:42:37 (64.254.110.201)
Great protactor and a great guy. This forum is lucky to have him around. Dan .......
290: Vintage Asylum, RE: Crap Shoot (0.00)
Posted by DanK tubes on 2009-09-22, 09:14:05 (64.254.110.201)
Thanks for the response. Your system looks great! I really like that old Pioneer gear. Dan .......
291: Vintage Asylum, Pioneer Spec System (0.00)
Posted by DanK tubes on 2009-09-21, 21:05:49 (74.220.74.24)
How much do you guys think this is worth? No "melfunctions" and "original Carhridge" included. No affiliation, just curious. Dan .......
292: MagneQuest/Peerless Forum, RE: B7 10k:10k volume control (0.00)
Posted by DanK tubes on 2009-09-18, 12:15:25 (64.254.110.201)
Hi Steve, Thanks for the comments. My first thought was a resistor in parallel with a log pot would not really have log response. I guess I should have thought it through more before posting. I'll jus .......
293: MagneQuest/Peerless Forum, link corrected above (nt) (0.00)
Posted by DanK tubes on 2009-09-18, 08:57:38 (64.254.110.201)
nt .......
294: MagneQuest/Peerless Forum, B7 10k:10k volume control (0.00)
Posted by DanK tubes on 2009-09-17, 23:00:34 (64.254.110.201)
I've seen the B7 10k:10k transformer used to provide a constant 10k load for a volume control. Mike has posted this up before (see link below). This looks like a nice passive volume control. However, .......
295: Vintage Asylum, RE: Ampex Crescendo Console (0.00)
Posted by DanK tubes on 2009-09-17, 18:13:23 (74.220.74.24)
I have the schematics and some other info. If you still need them send me a note. After restoration, I've been really happy with mine. Dan .......
296: Tube DIY Asylum, RE: Latest Schematic (0.00)
Posted by DanK tubes on 2009-09-16, 15:21:30 (64.254.110.201)
Hi Dave, Thanks for pointing that out. I'm still learning here. I hope you don't mind a question. I understand that without the feedback from a bypass capacitor you should get less gain. However, you .......
297: Tube DIY Asylum, Latest Schematic (0.00)
Posted by DanK tubes on 2009-09-14, 11:33:48 (64.254.110.201)
OK, so here is an updated schematic with corrections. Thanks for all the help so far. And I'll gladly take any more comments... or wise cracks too. Dan .......
298: Tube DIY Asylum, RE: questions on a new design (0.00)
Posted by DanK tubes on 2009-09-12, 07:46:41 (74.220.74.24)
yeah, solder and listen needs to be done for this case. thanks, dan man, i've gotta get that schematic corrected soon... .......
299: Tube DIY Asylum, RE: Another thing ... (0.00)
Posted by DanK tubes on 2009-09-11, 22:17:44 (74.220.74.24)
Hi Mike, Thanks for the confirmation. The OPTs to be used are from your custom build of Robin Hoods that you did last year with bell ends. I can't wait to hear them. Dan .......
300: Tube DIY Asylum, RE: questions on a new design (0.00)
Posted by DanK tubes on 2009-09-11, 21:33:19 (74.220.74.24)
Thanks for the note. I'm sure I'll wind up testing the supressor tied to the cathode, but I have seen a lot of people that get better results with it tied to the anode on high Gm tubes. Damir found it .......
301: Tube DIY Asylum, Oops! thanks guys (nt) (0.00)
Posted by DanK tubes on 2009-09-11, 09:02:23 (64.254.110.201)
nt .......
302: Tube DIY Asylum, RE: Another thing ... (0.00)
Posted by DanK tubes on 2009-09-11, 09:00:34 (64.254.110.201)
The BCP-16 Ni grid choke has over 3000H inductnace. I don't remember the DCR exactly, but it's something like 3k ohms. The goal is a flat freq response, but I wouldn't be opposed to a slight bass lift .......
303: Tube DIY Asylum, RE: questions on a new design (0.00)
Posted by DanK tubes on 2009-09-11, 06:57:52 (74.220.74.24)
Thanks for the comments. I was using the 7788 mainly because I had some nice Amprex versions on hand that I wanted to build with. Good catch on the bias point typo. I was planning to use the recommend .......
304: Tube DIY Asylum, RE: questions on a new design (0.00)
Posted by DanK tubes on 2009-09-10, 22:04:13 (74.220.74.24)
Thanks for the response. I was using the 275V, -56V RCA operating points. RCA also has a recommended 250V, -50 point but I never see anyone using that one. Maybe I should give it a try. Dan ::: TOPI .......
305: Tube DIY Asylum, questions on a new design (0.00)
Posted by DanK tubes on 2009-09-10, 21:12:21 (74.220.74.24)
Here is a schematic for a 7788 drive 45 SET that I drew up. I've collected all the iron, caps, tubes and two chassis but I have some questions before I warm up the soldering iron. First, I'm new to t .......
306: Tube DIY Asylum, RE: Work in progress... (0.00)
Posted by DanK tubes on 2009-09-09, 11:25:39 (64.254.110.201)
Just curious, what are you using to draw your schematics? It looks great. Dan .......
307: Tube DIY Asylum, RE: free to a good home, collection of Audio Amateur and Glass Audio magazines (0.00)
Posted by DanK tubes on 2009-09-08, 20:36:16 (74.220.74.24)
I would love to take those off your hands. I've read my old sound practices so many times it would be nice to have another set of publications. Thanks for the offer. Dan .......
308: Vintage Asylum, RE: 15" speakers - RCA and Altec (0.00)
Posted by DanK tubes on 2009-09-07, 20:01:45 (74.220.74.24)
Sorry, nothing to trade, but you might want to post this over at the Altec Hostboard. There are a lot of die hard fans there. Dan .......
309: Tube DIY Asylum, RE: Anyone try common mode choke on AC heated DHT? (0.00)
Posted by DanK tubes on 2009-09-03, 10:56:31 (64.254.110.201)
Hi Al, can you elaborate on what is properly implemented DC for filaments on a 45? A lot of people seem to poo poo DC on 45 heaters, but I was thinking of giving it a shot. Thanks, Dan .......
310: Bottlehead Forum, RE: FC-1 with 45's? (0.00)
Posted by DanK tubes on 2009-08-22, 22:51:24 (74.220.74.24)
Hi Paul, Thanks again for that Ampex tweeter info you sent me. I thought that common-mode noise was just between the neutral and ground lines. In any case, now I can see that shielding on both sides o .......
311: Bottlehead Forum, RE: FC-1 with 45's? (0.00)
Posted by DanK tubes on 2009-08-22, 13:40:30 (74.220.74.24)
So you think it's more of a wiring problem than an AC heating problem. Twisted wires seems crucial with 1.5 amp filaments. I expect there to be quite a strong magnetic field from that much current. Bu .......
312: Bottlehead Forum, FC-1 with 45's? (0.00)
Posted by DanK tubes on 2009-08-21, 22:58:56 (74.220.74.24)
I've heard a lot of people claim that 45's sound their best with AC heating. But to cut down on hum, I was thinking of trying to heat 45's with a full wave rectifier followed by FC-1's. Has anyone he .......
313: MagneQuest/Peerless Forum, seperate filament transformers? (0.00)
Posted by DanK tubes on 2009-08-17, 13:04:18 (64.254.110.201)
I've seen this topic come up before on other boards (see below) and thought I would check in here for an opinion. Some people think that amps sound better with separate filament transformers for DHTs. .......
314: Tube DIY Asylum, RE: Westcap Teflon caps (0.00)
Posted by DanK tubes on 2009-08-05, 22:13:54 (74.220.74.24)
Yeah, that's why I was looking for some confirmation. They seem a little small compared to the FT-3's. And at that price I don't think I'd want to cut one up to see what's inside. Dan .......
315: Tube DIY Asylum, Westcap Teflon caps (0.00)
Posted by DanK tubes on 2009-08-05, 11:25:20 (64.254.110.201)
Has anyone tried the hermetically sealed Westcap Teflon caps (0.22uF @400V) that they have for sale over at Surplus Sales of Nebraska? I read that Arizona Capacitors, the company that makes V-Caps, wa .......
316: MagneQuest/Peerless Forum, RE: I LOVE IT (0.00)
Posted by DanK tubes on 2009-08-04, 13:26:23 (64.254.110.201)
Thanks, it's an original 72 bike. We did a lot of work restoring it. Even machined new parts to rebuild the rear shocks and keep it original. My dad also has a 74 square case 750ss and a 76 900ss. All .......
317: MagneQuest/Peerless Forum, Runs on electrons (0.00)
Posted by DanK tubes on 2009-08-04, 09:05:58 (64.254.110.201)
This one (one of my dad's ducks) runs on electrons. It's a much better design I must say. Dan .......
318: MagneQuest/Peerless Forum, Runs on smoke (0.00)
Posted by DanK tubes on 2009-08-04, 09:03:06 (64.254.110.201)
Ahh, Lucas the prince of darkness. Here's an example for you. My bike runs on smoke and light rain or puddles will help it escape. Dan .......
319: Vinyl Asylum, RE: SUT measurement specs (0.00)
Posted by DanK tubes on 2009-07-31, 22:53:31 (74.220.74.24)
Thanks for the post. Cool stuff! The Cinemag has the same problems that my Beyer's have at higher frequencies. I should be able to get some pictures posted next week comparing the two. I always thoug .......
320: Vinyl Asylum, SUT measurement specs (0.00)
Posted by DanK tubes on 2009-07-30, 16:50:35 (64.254.110.201)
I have a Denon DL103 that I used in the past with a set of Beyer Dynamic 15:1 SUTs. A lot of people like the Beyer's and I thought they sounded pretty good too. Recently I picked up some non-descript .......
321: Tube DIY Asylum, RE: SWING OR GAIN? (0.00)
Posted by DanK tubes on 2009-07-24, 21:19:55 (74.220.74.24)
Calculating the gain needed is no problem. For a typical 1V input signal, first figure out the power you are trying to get from the 300b. Remember, watts = V^2/R. Here V is the output voltage to the s .......
322: MagneQuest/Peerless Forum, RE: TB-103 ID (0.00)
Posted by DanK tubes on 2009-07-23, 22:36:55 (74.220.74.24)
Hi Topper, Thanks for the info. There is one input to the thing that looks like a mic connection. I think I'll fire it up with a variac to try and figure out what it does. I didn't realize it was tha .......
323: MagneQuest/Peerless Forum, Altec power supply ID? (0.00)
Posted by DanK tubes on 2009-07-22, 22:49:01 (74.220.74.24)
I bought this mystery piece at the CHRS swap meet last weekend for $5. I have no idea what it is, but it has a couple of pieces of Altec iron in there. The power transformer is a TP-608-A. The smaller .......
324: SET Asylum, RE: Volume control (0.00)
Posted by DanK tubes on 2009-07-02, 19:57:47 (74.220.74.24)
Just to be safe you should look at the schematic for the preamp to make sure the are compatible. Here is a situation I ran into. I built an RCA phono stage that had enough gain to drive directly into .......
325: Tube DIY Asylum, Thank you Mike! (0.00)
Posted by DanK tubes on 2009-06-29, 19:35:59 (74.220.74.24)
For taking the time to write out all that detail. A really great reply. Dan .......
326: Vintage Asylum, I think this is the site (0.00)
Posted by DanK tubes on 2009-06-26, 10:15:14 (64.254.110.201)
Couldn't link with the previous post. Is this it? No affiliation either. Dan .......
327: Tube DIY Asylum, Astron cap question (0.00)
Posted by DanK tubes on 2009-06-16, 22:18:31 (74.220.74.24)
I have a couple of 0.27uF Astron PIO caps. One is the AAQFP type rated at 200V, and the other is TQFP type rated 300V. Other than the label they look identical (and just like Vitamin Q's). Does anyone .......
328: High Efficiency Speaker Asylum, RE: Speaker driver ID (0.00)
Posted by DanK tubes on 2009-05-28, 16:44:37 (69.26.32.67)
Hi Paul, Cool, I'll send you an email about this. Dan .......
329: High Efficiency Speaker Asylum, RE: Speaker driver ID (0.00)
Posted by DanK tubes on 2009-05-27, 10:34:25 (69.26.32.67)
Hi Paul, Thanks for the link. The speaker is marked with G188935. So it looks like they are GE speakers (code 188) that were made in the 35th week of 1959. Searching the asylum and on google still doe .......
330: High Efficiency Speaker Asylum, Speaker driver ID (0.00)
Posted by DanK tubes on 2009-05-26, 14:48:55 (69.26.32.67)
Hello All, I have some tweeters that came from a 60's Ampex stereo console and I'm looking for some more information on them. They are AlNiCo bullet tweeters, with nice big magnets, and I heard they w .......
331: SET Asylum, RE: INFORMAL POLL: Who be curious to see a THD plot of Jeff Medwin's (AKA drlowmu's) very best SET amp Y/N? (0.00)
Posted by DanK tubes on 2009-05-19, 13:00:17 (69.26.32.67)
Everyone knows that SET amps have higher distortion numbers. The fact that there are so many SET fans (myself included) tells me that there is a pleasing quality of harmonic distortion in music. I've .......
332: Tube DIY Asylum, formula question (0.00)
Posted by DanK tubes on 2009-04-14, 10:18:39 (69.26.32.67)
I was trying out the formula, but it looks like a there was parenthesis left out. Is is suppose to be: [(2*pi*120*L)+R]*C > 0.1 Thanks, Dan .......
333: Tube DIY Asylum, thanks Michael nt (0.00)
Posted by DanK tubes on 2009-03-27, 06:43:49 (74.220.74.24)
nt .......
334: Tube DIY Asylum, western electric cap ID (0.00)
Posted by DanK tubes on 2009-03-26, 21:47:17 (74.220.74.24)
I've got a bunch of these Western Electric caps but I don't know anything about them. Has anyone seen these before? I'm wondering what kind of material and what voltage rating they are. Is there a ros .......
335: High Efficiency Speaker Asylum, tall corner cabinet (0.00)
Posted by DanK tubes on 2009-03-25, 06:54:37 (74.220.74.24)
If you are interested in tall corner cabinets then check out Billfort's design (see link). There is a lot of posts about these at audiokarma. Suppose to sound great. I've never heard them, but if I ha .......
336: Tube DIY Asylum, RE: Nope. (0.00)
Posted by DanK tubes on 2009-03-19, 12:23:22 (69.26.32.67)
Hi Allen, Just curious, do you have any recommendations for a DIY "hifi" quality phono stage? Thanks, Dan .......
337: Tube DIY Asylum, thanks everyone! (0.00)
Posted by DanK tubes on 2009-03-19, 12:19:18 (69.26.32.67)
When I started with this hobby I was just building other peoples circuits. After studing enough, now I'm figuring out what the electrons are actually doing. I was using this phono stage to drive a an .......
338: Tube DIY Asylum, RCA Phono question (0.00)
Posted by DanK tubes on 2009-03-18, 22:01:33 (74.220.74.24)
Hi all, I built a phono stage that is a modified version of the RCA phono preamp. The schematic is linked below. The output has a 0.22uF cap to block the DC, and a 500kohm pot for volume control. To m .......
339: MagneQuest/Peerless Forum, RE: Baby Ongaku (0.00)
Posted by DanK tubes on 2009-03-16, 12:48:40 (69.26.32.67)
Beautiful! What material did you use for the round corner pieces? Dan .......
340: MagneQuest/Peerless Forum, RE: Project Pics (0.00)
Posted by DanK tubes on 2009-03-16, 12:44:26 (69.26.32.67)
Thanks. It's funny, I built the boxes a while back, but they look a lot like the latest Wavelength Cardinal boxes. Just a coincidence. Dan .......
341: MagneQuest/Peerless Forum, RE: Gorgeous! (0.00)
Posted by DanK tubes on 2009-03-15, 15:43:27 (74.220.74.24)
Thanks cafeinator and Anand. I really only changed the power supply. The first attempt was using solid state UF1007 rectifiers with a delay relay to warm up the filaments. The first pics can be seen i .......
342: MagneQuest/Peerless Forum, Project Pics (0.00)
Posted by DanK tubes on 2009-03-14, 13:36:05 (74.220.74.24)
The forum seems a little slow these days, so here are some pics to keep it going. This is a pair of monoblocks I built with Magnequest RH40 outputs. The circuit is Gordon's Bugle 45 with a few modific .......
343: Tube DIY Asylum, RE: TH-SA and TS-HB cap voltage (0.00)
Posted by DanK tubes on 2009-03-14, 13:27:47 (74.220.74.24)
The THSA should be OK for 330VDC. If you are worried about it, and want a higher safety margine, the TSHB should sound good too. Check out Poinz's web site, that's were I picked up on using these. He .......
344: Tube DIY Asylum, Second that! (0.00)
Posted by DanK tubes on 2009-03-13, 22:45:34 (74.220.74.24)
I built the Bugle 45 circuit into a pair of monoblocks and used 120uF panasonic TSHA caps. Although I never tried the cerifines, the amp sounds great with these. I first used UF1007 diodes for the rec .......
345: Vintage Asylum, RE: I Use Brass Rivets for mounting spacers... (0.00)
Posted by DanK tubes on 2009-03-09, 21:41:33 (74.220.74.24)
Thanks for the tip. Yeah, that VTA problem had me thinking I needed to find the right type of spacer. I'll have to give the screw driver method a try. :) I'm excited about this one. After worrying abo .......
346: Vintage Asylum, 481 mounting spacers? (0.00)
Posted by DanK tubes on 2009-03-09, 08:34:19 (69.26.32.67)
Hello Chef, I would like to mount up a Stanton 380 and am trying to figure out what to use for spacers. Is there a standard spacer type that Stanton made for these, or is this a DIY type job? Any reco .......
347: Tube DIY Asylum, Common cathode RC for DHT? (0.00)
Posted by DanK tubes on 2009-02-24, 13:13:40 (69.26.32.67)
I have a power transformer with 5V 3A taps (no center tap) and I would like to use it to light up two 45's in a stereo SET amp. I've seen this suggested at Gabe V's web site (see link below), but thou .......
348: High Efficiency Speaker Asylum, thanks guys (nt) (0.00)
Posted by DanK tubes on 2009-02-03, 21:52:02 (74.220.74.24)
nt .......
349: High Efficiency Speaker Asylum, Karlson Questions (0.00)
Posted by DanK tubes on 2009-02-03, 10:41:39 (69.26.32.67)
So I picked up these beautiful Karlson cabs the yesterday. The price for just the boxes was so nice I had to give them a try. From all I've heard, they seem like a love it or hate it type speaker. I n .......
350: Tube DIY Asylum, RE: any Organic Chemists out there? (0.00)
Posted by DanK tubes on 2009-01-20, 06:21:36 (74.220.74.24)
You could try the MSDS sheet for the product you have. If there is any other solvent in the mix they should list it there. My guess is the other 9% is water. Dan .......
351: High Efficiency Speaker Asylum, RE: My son has one. (0.00)
Posted by DanK tubes on 2009-01-15, 09:55:09 (69.26.32.67)
Which driver is he using and how does it sound? Thanks, Dan .......
352: High Efficiency Speaker Asylum, RE: Voigt Home Constructors Horn plans (0.00)
Posted by DanK tubes on 2009-01-14, 21:48:55 (74.220.74.24)
Yep, that's me. That's quite a collection of plans you have. I hadn't heard about the home constructors horn until now. It looks pretty reasonable to build. Thanks again, Dan .......
353: High Efficiency Speaker Asylum, Voigt Home Constructors Horn (0.00)
Posted by DanK tubes on 2009-01-14, 13:34:18 (69.26.32.67)
Do any of yous guys know about this horn? It doesn't look too difficult to build, compared to the Voigt Domestic Corner Horn. Thanks, Dan .......
354: Vintage Asylum, RE: I was looking on ebay for a parts laptop and saw this picture; look in the backround... (0.00)
Posted by DanK tubes on 2008-12-20, 06:26:08 (74.220.74.24)
Is that the limited edition McIntosh singing fish! I heard that thing sounds great with choke loaded, single ended, all DHT, silver wired outputs. Just perfect for the holidays. :) Dan .......
355: MagneQuest/Peerless Forum, thanks (nt) (0.00)
Posted by DanK tubes on 2008-11-14, 21:27:19 (74.220.74.24)
nt .......
356: MagneQuest/Peerless Forum, dynamic load line with a grid choke? (0.00)
Posted by DanK tubes on 2008-11-14, 16:52:00 (74.220.74.24)
Hi All, I'm laying out a 7788 driver stage (triode connected) for a 45 parafeed amp and have a question. For design, the Crowhurst papers suggest using the plate resistor to set up the static load lin .......
357: MagneQuest/Peerless Forum, thanks Paul (nt) (0.00)
Posted by DanK tubes on 2008-11-05, 12:07:44 (69.26.32.67)
nt .......
358: MagneQuest/Peerless Forum, RE: Best thing to do ... (0.00)
Posted by DanK tubes on 2008-11-03, 20:57:49 (74.220.74.24)
Hi Paul, Thanks for the post. I've built a Bugle SET and have been really happy with the sound, but I always notice the background hum when playing through Altec 604s. Gordon always suggests running A .......
359: High Efficiency Speaker Asylum, anyone looking for horns? (0.00)
Posted by DanK tubes on 2008-10-29, 21:45:13 (74.220.74.24)
this guy sure has a bunch. no affiliation, just passing it on. it's been up there for ~5 hours, so they might be all gone by now. dan .......
360: SET Asylum, Thanks! and a side question (0.00)
Posted by DanK tubes on 2008-10-24, 06:13:52 (74.220.74.24)
Thanks for the nice summary. A friend of mine has a General Radio SET audio amplifier that looks like it was from the 20s or 30s. It uses a transformer input to a single WE 205 tube to a transformer .......
361: Tube DIY Asylum, Good one! (nt) (0.00)
Posted by DanK tubes on 2008-09-26, 06:30:53 (74.220.74.24)
nt .......
362: SET Asylum, Darling SET (0.00)
Posted by DanK tubes on 2008-09-16, 21:46:45 (74.220.74.24)
Yeah, I'm running a 1626 darling in my office. My office neighbors are always amazed at what 700mW can do. Dan .......
363: Tube DIY Asylum, That's it! (0.00)
Posted by DanK tubes on 2008-09-04, 15:40:04 (69.26.32.67)
The unit on the right side is almost identical. The two bottom power supplies with 6x 6080 regulators are 200VDC 1amp supplies, and the two above that are 300VDC. Yeah, my wife was shaking her head wh .......
364: Tube DIY Asylum, RE: I found a little (0.00)
Posted by DanK tubes on 2008-09-04, 12:54:39 (69.26.32.67)
Hi Russ, sounds like you are getting warmer. However, this is a pretty big cabinet, roughly 7' tall with the 10 different (rack mounted) regulated power supplies, a control pannel, a pannel with outpu .......
365: Tube DIY Asylum, RE: Do you have a brand and model#? (0.00)
Posted by DanK tubes on 2008-09-03, 07:56:56 (69.26.32.67)
Hi Russ, Yes, The power supply comes from a: Transmitting Set, Coordinate Data AN/FST-1. The power supply is labled: Control, Power Supply Set C-1828/FST-1. It was made by Lewyt Manufacturing Company. .......
366: Tube DIY Asylum, RE: regulated power supply rebuild? (0.00)
Posted by DanK tubes on 2008-09-02, 16:00:09 (69.26.32.67)
Thanks for the input. I got it from a guy who lives in my neighborhood. It use to be a supply for a military transmitter. Three guys and a truck got it home. It's more of a ship anchor than a boat anc .......
367: MagneQuest/Peerless Forum, Sold! (nt) (0.00)
Posted by DanK tubes on 2008-09-02, 08:01:11 (69.26.32.67)
nt .......
368: Tube DIY Asylum, regulated power supply rebuild? (0.00)
Posted by DanK tubes on 2008-09-01, 14:32:58 (74.220.78.209)
The other day I picked up the mother of all boat anchor tube regulated power supply cabinets. This military surplus beast has 10 different supplies. 5x 0-50V, 2x 900V, 2x 0-300V, and 1x 0-200V. The p .......
369: MagneQuest/Peerless Forum, RE: folks.... please clear with me before posting "for sale" (nt) (0.00)
Posted by DanK tubes on 2008-08-29, 12:47:27 (69.26.32.67)
Hi Mike, you cleared the For Sale post of these back in March. I hope it isn't a problem. Dan .......
370: MagneQuest/Peerless Forum, Yes RH-PF (0.00)
Posted by DanK tubes on 2008-08-29, 04:59:16 (74.220.78.209)
sorry for the confusion. Dan .......
371: MagneQuest/Peerless Forum, RH-40 PF for sale (0.00)
Posted by DanK tubes on 2008-08-28, 22:38:55 (74.220.78.209)
Mike OK'd this a little while back, so here goes. I've got a pair of RH-40 PF transformers that I bought, but never used. So I'm selling them for $150.00. That includes shipping anywhere in the conti .......
372: MagneQuest/Peerless Forum, Santa Cruz Organics! (0.00)
Posted by DanK tubes on 2008-07-15, 12:27:23 (69.26.32.67)
if you don't mind stirring, this is the best tasting stuff I've found. Dan .......
373: Vintage Asylum, a good deal possibly? (0.00)
Posted by DanK tubes on 2008-05-17, 21:50:36 (74.220.78.209)
No affiliation, but I saw this post on craigslist. I'm not a vintage expert, but it looks like a pretty good deal. What do you think, is it worth $850? Dan .......
374: High Efficiency Speaker Asylum, nice altec deal (0.00)
Posted by DanK tubes on 2008-02-19, 08:33:51 (69.26.32.67)
I just saw these on Craigslist and thought that it looked like a good deal for somebody. No affiliation, just passing on the link. Dan .......
375: Tubes Asylum, I agree. Thanks! nt (0.00)
Posted by DanK tubes on 2008-01-25, 12:03:25 (69.26.32.67)
nt .......
376: Vintage Asylum, Thanks. nt (0.00)
Posted by DanK tubes on 2008-01-23, 08:12:48 (69.26.32.67)
nt .......
377: Vintage Asylum, RE: anyone identify these speakers? (0.00)
Posted by DanK tubes on 2008-01-22, 14:49:08 (69.26.32.67)
Here are more details: 12" woofer 8" Mid 2" tweeter 2ft tall w/ out stand 2' 5" w/ stand Thanks, Dan .......
378: Vintage Asylum, anyone identify these speakers? (0.00)
Posted by DanK tubes on 2008-01-22, 14:46:01 (69.26.32.67)
I thought these looked pretty cool and tried to get themt, but they were already sold. I thought I would check to see if anyone recoginzes them. Hopefully they weren't anything special... Thanks, Dan .......
379: SET Asylum, RE: Darling/1626-based amp..signature sound? (0.00)
Posted by DanK tubes on 2007-10-29, 15:11:52 (69.26.32.67)
I built one of these for my office. I followed most of the schematic from Sound Practices. I switched out the 1626 cathode cap to a Solen (only 47uF I think) and the power supply is a choke input load .......
380: Vinyl Asylum, funny description (0.00)
Posted by DanK tubes on 2007-10-25, 07:15:14 (74.220.78.209)
I was watching this Bogen B62 turntable on ebay (# 180172746527 ) and saw this funny description. When asked about the condition the seller wrote back this: "it does turn on okay and appears to operat .......
381: High Efficiency Speaker Asylum, jbl cinema on craigslist (0.00)
Posted by DanK tubes on 2007-07-09, 12:45:24 (69.26.32.67)
Hi Guys, I saw these speakers on craiglist and thought somebody might be interested in them. They look like JBL 4648 boxes with 2360A horns and 2045J drivers. The horns seem to be a good deal. My hous .......
382: MagneQuest/Peerless Forum, transformer finishing (0.00)
Posted by DanK tubes on 2007-05-29, 20:58:12 (65.89.84.2)
I've got a pair of RH-40 outputs and I'd like to paint the brass channels to match the rest of my project. These came with some kind of finish on the brass. Does anyone know if it's OK to paint over t .......
383: High Efficiency Speaker Asylum, interesting Altec speakers (0.00)
Posted by DanK tubes on 2007-05-15, 07:48:25 (74.220.78.209)
I thought you guys might be interested in these. Anybody recognize them? No affiliation. Best regards, Dan .......
384: Tube DIY Asylum, Re: 5751 operating points (0.00)
Posted by DanK tubes on 2007-03-16, 16:07:20 (69.26.32.67)
I know that the 5751 has a lower gain, but I didn't realize the plate resistance was lower. That makes sense with what I saw (lower plate voltage and higher bias voltage). People always talk about dro .......
385: Tube DIY Asylum, Re: 5751 operating points (0.00)
Posted by DanK tubes on 2007-03-16, 07:48:31 (74.220.78.209)
Hi Jim, Thanks for the info. I didn't expect that much variation from tube to tube. I put a tube shield on as an afterthought, but I guess I should role through the others again with the sheild on. D .......
386: Tube DIY Asylum, 5751 operating points (0.00)
Posted by DanK tubes on 2007-03-15, 21:26:05 (74.220.78.209)
I finally got that hum problem worked out on my phono preamp. Thanks to everyone who helped out with my previous questions on that. After much filtering, shielding, and DC on the filaments, the last p .......
387: Tube DIY Asylum, Re: MM phono stage hum (0.00)
Posted by DanK tubes on 2007-02-28, 13:52:53 (69.26.32.67)
Thanks for all the responses guys. It sounds like the probe acting as an antenna is pretty normal. I'll keep looking for hum. For more details, I'm building from scratch a modified Audio Invations P2 .......
388: Tube DIY Asylum, MM phono stage hum (0.00)
Posted by DanK tubes on 2007-02-28, 09:20:00 (63.249.118.5)
I've been working on a MM phono stage and have been struggling with a bad hum problem. Last night when I was poking around with a oscilloscope I realized that the probe itself is picking up ~2mVpp sig .......
389: Tube DIY Asylum, cathode follower suggestions please (0.00)
Posted by DanK tubes on 2006-11-20, 21:56:00 (63.249.121.2)
Hi All, I just finished putting together the RCA RIAA phono stage. All of the voltages and currents are right on, and using a function generator and scope I can see the thing is working. Right now I'v .......
390: Tube DIY Asylum, Thanks for the advice! (nt) (0.00)
Posted by DanK tubes on 2006-10-17, 10:44:11 (69.26.32.67)
nt .......
391: Tube DIY Asylum, RIAA capacitor selection (0.00)
Posted by DanK tubes on 2006-10-16, 15:39:35 (69.26.32.67)
Hello All, I'm putting together a RIAA phono stage from the RCA 12ax7 schematic (see link below). For the RIAA capacitors, 3.3nF and 10nF, I have on hand either Silver Mica caps or Mylar caps. Are eit .......
392: Tube DIY Asylum, Re: Filament transformer question (0.00)
Posted by DanK tubes on 2006-09-14, 22:19:09 (63.249.121.93)
I saw on the Handmade Electronics web site that they recommend the Hammond 166J2 (2.5V /1 amp) for use with 45s. I guess that under the high load it drops the voltage down to the correct value. This p .......
393: Vinyl Asylum, Re: Turntable hell - almost makes me want to cry ... (0.00)
Posted by DanK tubes on 2006-09-06, 20:36:58 (63.249.121.93)
Yeah, I saw that post on Craigslist and called the guy within a couple hours but never heard back. Even with the damage I bet that someone got a good deal. Dan .......
394: Tubes Asylum, 6cz5 max ratings (0.00)
Posted by DanK tubes on 2006-08-08, 16:30:40 (69.26.32.67)
I'm looking to substitube something for the expensive 6973 tubes in my Ampex monoblocks. The plate voltage on the 6973 is 375V. The 6CM6 and 6CZ5 are suppose to be good substitutes, but the max plate .......
395: High Efficiency Speaker Asylum, Re: Chicago Horn Club Meeting Results and Pics (0.00)
Posted by DanK tubes on 2006-07-14, 11:27:50 (69.26.32.67)
Thanks for the summary of listening experiences. I may just have to get a pair of Fostex 166e's. Can you provide any comments people have given on the Karlson speakers? Dan .......
396: Tube DIY Asylum, Re: Low DCR - a possible explanation (0.00)
Posted by DanK tubes on 2006-07-05, 13:37:13 (69.26.32.67)
Self resonance comes from the LC circuit that is set up from the inductance in the coils and the capacitance between the wires of the coil. There is always a capacitance between two conductors, and in .......
397: Tubes Asylum, Re: Ampex monoblock amps + preamp +tuner (0.00)
Posted by DanK tubes on 2006-05-26, 13:21:53 (69.26.32.67)
Last year I picked up an Ampex console with 6973 monoblocks. These are pretty nice units. I wound up replacing every cap in both the amps and in the preamp. I used orange drop 716 caps to replace the .......
398: Tube DIY Asylum, Thanks for the help (nt) (0.00)
Posted by DanK tubes on 2006-04-27, 07:52:25 (69.3.28.132)
nt .......
399: Tube DIY Asylum, guitar amp speker out (0.00)
Posted by DanK tubes on 2006-04-26, 15:09:03 (69.26.32.67)
I've took this old Emud desktop radio and rewired it into a Fender Princeton 5F2 guitar amp following notes from Angela's website. The circuit is a single ended 6V6, and it sounds pretty cool running .......
400: Tube DIY Asylum, Arco transformers (0.00)
Posted by DanK tubes on 2006-04-24, 22:57:08 (69.3.93.15)
I picked up a couple of Arcosound ultralinear TO-300 transfomers for $20 figuring I could do something with them. They are new, but a little scuffed up from the years. I found an article on Tube Cad J .......
401: Vinyl Asylum, Recognize this tonearm? (0.00)
Posted by DanK tubes on 2006-03-30, 12:51:51 (69.26.32.67)
OK, I finally got a nice turntable. It's a 1957 Fairchild 412. I guess these were top of the line back then. I've attached a link where you can see some pictures of it. Does anyone know what kind of t .......
402: MagneQuest/Peerless Forum, Low power 845 (0.00)
Posted by DanK tubes on 2006-02-01, 16:06:12 (69.26.32.67)
Mike, I've seen you talk about a low power 845 project that could work with your RH-40 5K output transformers. Have you, or anyone, come up with a design with voltages that are acceptable for the RH-4 .......
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