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1: Tube DIY Asylum, RE: DIY Lettering For Chassis. (0.00)
Posted by LinuxGuru on 2024-04-01, 07:56:45 (83.99.228.190)
Laser engraving, cheap and quick. .......
2: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-23, 05:46:30 (83.99.228.190)
Phase inverter DC balance runaway have nothing to do with the output transformer. Build is fine tuned and is stable right now, with flat frequency response 20 - 50000 Hz. Regarding your question - .......
3: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-21, 13:44:29 (83.99.228.190)
> Thanks for clarifying that. Since your experience and mine are > totally opposite I was afraid it would confuse people who own > "genuine" Citation IIs. I never owned original vintage Citation II .......
4: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-20, 23:43:59 (83.99.228.190)
> So IMHO it seems certain that something in your build is > causing instability that is NOT present in the original amps. Yes, I eliminated phase inverter balancing pot, removed 2 feedback loops from .......
5: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-20, 16:49:57 (83.99.228.190)
Hi, Jim, thanks a lot for reply! When assembled amp prototype I followed original schematic, and run into phase inverter DC imbalance problem. SAMS schematic have voltage data this is why I uploade .......
6: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-20, 15:11:17 (83.99.228.190)
I tested assembled amp, and can now confirm that everything advised by dcgillespie (Dave from AudioKarma) is 100% correct, tail resistor 270 Ohm instead of 220, separating screen split supply with 2 x .......
7: Tube DIY Asylum, RE: Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-16, 16:43:14 (83.99.228.190)
Photo of the bottom PCB layer of an amp. .......
8: Tube DIY Asylum, Q: Citation2 Build-Huge Phase Inverter DC Balance Runaway (0.00)
Posted by LinuxGuru on 2023-03-16, 16:41:36 (83.99.228.190)
Hi, I have built Citation 2 clone on a prototyping board, and now having strange problem with *HUGE* Schmitt phase inverter DC balance runaway. Prior building this amp I've done extensive simula .......
9: Tubes Asylum, Mirrors of once great but now defunct tube web sites (0.00)
Posted by LinuxGuru on 2022-12-04, 04:09:55 (83.99.228.190)
Hi! I made a mirrors (web copies) of these once great but now defunct tube web sites: 1) Patrick Turner's (Turner Audio Australia) web site, status: complete. contains a tons of valuable information a .......
10: Tube DIY Asylum, RE: Thanks for your input, Tre' (0.00)
Posted by LinuxGuru on 2022-11-20, 15:15:19 (83.99.228.190)
> If someone wants a really good constant current source, with a real > "Mu" output that provides a very low source impedance, check out > Gary Pimms CCS. Copies of Garry Pims articles, among several .......
11: Tube DIY Asylum, RE: DrLowMu, a suggestion: (0.00)
Posted by LinuxGuru on 2022-02-08, 11:33:35 (83.99.228.190)
Hi, You can also use Wordpress hosting services to create simple web site. Wordpress is something like MS Word for building web sites, quite easy to begin with. Here is a list free WordPress hosting s .......
12: Tube DIY Asylum, RE: What are people using for their websites (0.00)
Posted by LinuxGuru on 2021-07-05, 11:51:16 (83.99.228.190)
+1 for WordPress. Takes some time to master but worth it. For simple web sites more then enough. A LOT of free themes. Here's mine made some years ago http://www.vacuum-tube.eu/wp/ .......
13: Tube DIY Asylum, RE: late to the party ... (0.00)
Posted by LinuxGuru on 2020-09-27, 11:02:19 (83.99.228.190)
> DF learned about "transfer efficiency" from mining engineers > many decades ago and applied it to his groundbreaking SE 2A3 > amplifiers designs. > In 2020, DF has bested the famous SE 2A3 with desi .......
14: Tube DIY Asylum, RE: Looking for info on Russian resistors... (0.00)
Posted by LinuxGuru on 2020-07-12, 10:47:31 (83.99.228.190)
> At this point I am trying the MLT-2 type and the C2-10 C2-10 - non-wirewound high-frequency thin film, perfect for vacuum tube circuits. .......
15: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by LinuxGuru on 2020-07-12, 04:59:43 (83.99.228.190)
Continued from my previous post. A similar chart for heat-treated permalloy - 45% (left column), 78% (right column). It is clearly visible that feeding even small DC bias makes even order harmonics .......
16: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by LinuxGuru on 2020-07-12, 04:40:37 (83.99.228.190)
> Although for the test set-up the DCV applied was closer to 50V, > more importantly the standing current was set at 70mA for all tests. > Among the transformers tested there were some DIY efforts .......
17: Tube DIY Asylum, RE: Looking for info on Russian resistors... (0.00)
Posted by LinuxGuru on 2020-07-10, 09:20:01 (83.99.228.190)
C5-35 - wirewound C2-23 - analog of OMLT (OMLT is a fire-resistant version of MLT if I rembember correctly). MLT - metal film. C2-33 - general purpose thin-film non-wirewound In general, MLT are excel .......
18: Tube DIY Asylum, RE: Why nickel? (0.00)
Posted by LinuxGuru on 2020-07-08, 02:49:35 (83.99.228.190)
> How many times have you encountered published distortion graphs and > HD spectrum plots of the OPTs that you cited? The answer is, None. The distortion graph for a vacuum tube output transformer req .......
19: Tube DIY Asylum, RE: cnc chassis ? (0.00)
Posted by LinuxGuru on 2020-06-28, 08:52:28 (83.99.228.190)
> What do you have to provide - DXF files or similar? 90% - DXF only, some accept PDF .......
20: Tube DIY Asylum, RE: cnc chassis ? (0.00)
Posted by LinuxGuru on 2020-06-28, 08:02:54 (83.99.228.190)
> Do these places mind doing small jobs??? Some yes some no, it depends. I have 3 cutting family-owned shops nearby that do small jobs. Same applies to USA I believe. .......
21: Tube DIY Asylum, RE: cnc chassis ? (0.00)
Posted by LinuxGuru on 2020-06-28, 00:59:26 (83.99.228.190)
Google "metal sheet laser cut" or "waterjet abrasive" with name of your city or region. .......
22: Tube DIY Asylum, RE: Very useful thanks (0.00)
Posted by LinuxGuru on 2020-02-02, 11:30:45 (83.99.228.190)
> I could still do with PSUD, but a friend has it. Why not LTSpice? Its a free and much more capable compared to PSUD. .......
23: Tube DIY Asylum, RE: Looking for ready made R-Core transformers... (0.00)
Posted by LinuxGuru on 2020-01-30, 10:57:16 (83.99.228.190)
Hi, You have to look on Alibaba.com or Aliexpress.com for a company which can supply single pieces. However, you need to specify low flux, e.g. 1.4 - 1.5T, otherwise, in order to reduce price they sup .......
24: Tube DIY Asylum, RE: Morgan Jones - "Building Tube Amplifiers" (0.00)
Posted by LinuxGuru on 2018-09-01, 03:12:15 (83.99.228.190)
Excellent book, one of the best ever made ! BTW, you may also be interested in certain articles from Linear Audio: https://linearaudio.net/ In the past they also sold separate articles as downloadable .......
25: SET Asylum, RE: Output Transformer Specifications (0.00)
Posted by LinuxGuru on 2018-08-26, 03:28:59 (83.99.228.190)
> a link of that super hitachi material? Its a Hitachi FT-8K50D, look at hysteresis, permeability and DC bias curves (light-blue line on graphs). Perfect for audio transformer use. I didn't remembe .......
26: SET Asylum, RE: Output Transformer Specifications (0.00)
Posted by LinuxGuru on 2018-08-25, 12:14:42 (83.99.228.190)
> Above the 70kHz trouble begins: resonances. The best transformer > winders keep these resonances under control. I can't believe > that you are not aware of this. You do know about this otherwise > s .......
27: Tube DIY Asylum, RE: 1.5 inch copper rod, more detail please (0.00)
Posted by LinuxGuru on 2017-12-17, 01:30:29 (83.99.228.190)
> I want to cut the rod into 1 inch segments to create > copper plate heatsinks for transmitter tubes Use sheet metal and waterjet abrasive in nearby metalworking facility to cut copper rings, then a .......
28: SET Asylum, RE: No, he's right! (0.00)
Posted by LinuxGuru on 2017-10-24, 12:43:38 (83.99.228.190)
> If you say you know.....answer the questions....otherwise we well think you are just telling fibs. > In your world you never give a straight answer to a straight up question. > We call that "talking .......
29: Tube DIY Asylum, RE: Very impressive but, (0.00)
Posted by LinuxGuru on 2017-10-17, 13:41:15 (83.99.228.190)
I'm aware Chinese PCB manufacturers can offer unbeatable price for bulk qty, however, my PCB made of qty of 20+ at best, so domestic manufacturer nearby is the most convenient solution. Actually I hav .......
30: Tube DIY Asylum, RE: PCB Mill (0.00)
Posted by LinuxGuru on 2017-10-16, 15:15:40 (83.99.228.190)
> Nice machine, but I'm surprised you can get the boards flat enough with that approach. I used surface scanning, otherwise this doesn't work. You can use either gcode-pcb (which have this feature), .......
31: Tube DIY Asylum, RE: Very impressive but, (0.00)
Posted by LinuxGuru on 2017-10-14, 03:02:38 (83.99.228.190)
> Wouldn't it be cheaper to get these made in a Chinese PC board shop > via conventional etching? Especially if you need more than one. Usually need just 1 or 2, so milling PCB is the fastest way to .......
32: Tube DIY Asylum, RE: breadboard design (0.00)
Posted by LinuxGuru on 2017-10-13, 14:46:48 (83.99.228.190)
And this is how its done. 1 - milling (engraving), depth 0.2mm (0.00787") 2 - drilling (there are many many holes) 3 - contour milling 250x165mm (9.84x6.5") .......
33: Tube DIY Asylum, RE: breadboard design (0.00)
Posted by LinuxGuru on 2017-10-13, 09:18:31 (83.99.228.190)
And this close-up of milled (engraved) board, pitch between holes 5mm (~6/32"), 1.4mm holes, pads octagonal/oval 3x2mm It had yet to be polished with sand paper. .......
34: Tube DIY Asylum, RE: breadboard design (0.00)
Posted by LinuxGuru on 2017-10-13, 09:10:49 (83.99.228.190)
And this is my latest design, large 250x160mm, 2 mm thick, one-sided, 5mm pitch, with universal socket placeholder, power supply bus planes, octagonal/oval shaped pads for max copper area and max d .......
35: Tube DIY Asylum, RE: breadboard design (0.00)
Posted by LinuxGuru on 2017-10-13, 09:04:07 (83.99.228.190)
After some time, I designed my own prototyping PCB, sturdy 2mm thick, with universal pads for 7, 9 and 8 pin octal sockets, and used stack of 2 for larger assembly. .......
36: Tube DIY Asylum, RE: breadboard design (0.00)
Posted by LinuxGuru on 2017-10-13, 08:57:12 (83.99.228.190)
This is one of the variants made several years ago, PP amp on Chinese breadboard, sold on eBay and Aliexpress. Board is only 1.5mm thick and not rigid enough to push a tube into socket, so I mounte .......
37: Tube DIY Asylum, RE: I used Google translator, here's what I got (0.00)
Posted by LinuxGuru on 2017-10-07, 11:28:32 (83.99.228.190)
Seller have 11733 transaction, out of which 4 are negative and 3 neutral. I wouldn't bother. .......
38: Tube DIY Asylum, RE: ALPS Pots - Are These Fake? (0.00)
Posted by LinuxGuru on 2017-10-06, 08:48:55 (83.99.228.190)
This is German company, working since 2003, not fake. .......
39: Tube DIY Asylum, RE: Slew rate, TIM hogwwash (0.00)
Posted by LinuxGuru on 2017-07-13, 14:58:15 (83.99.228.190)
> It would be nice if there was an easily accessible example of TIM > distortion on the web or disc, demonstrated with a short musical > performance repeated with more and more levels of TIMD until th .......
40: Tube DIY Asylum, RE: Slew rate, TIM hogwwash (0.00)
Posted by LinuxGuru on 2017-07-12, 14:57:36 (83.99.228.190)
> As to evidence contra to this, Otala (and others) published two JAES > papers ... In the first paper a group of six of the most sensitive > subjects (from a previous test of 68 listeners) were teste .......
41: Tube DIY Asylum, RE: Useless attempt (0.00)
Posted by LinuxGuru on 2017-07-02, 04:22:09 (83.99.228.190)
With similar success you can get same kind of meaningful information from countless BS artists in audio cable industry. Turning abracadabra into attractive and lucrative marketing slogans is something .......
42: SET Asylum, RE: When you get "Serious" about building SE amplifiers you get ones of these (0.00)
Posted by LinuxGuru on 2017-06-04, 05:10:01 (83.99.228.190)
> I have bought one of these XJW01 and I am trying to measure the > inductance of my Lundahl Double-C primaries interstage > transformer....and I am confused by the results: Large coils must be measu .......
43: Tube DIY Asylum, RE: Dynaco mod (0.00)
Posted by LinuxGuru on 2017-05-09, 12:52:00 (83.99.228.190)
I use fixed bias on output stage, so can't comment on this change, prefer to stay with it without any cathode resistors and capacitors. IMHO pure class A for push-pull doesn't make sense. PS. My previ .......
44: Tube DIY Asylum, RE: Dynaco mod (0.00)
Posted by LinuxGuru on 2017-05-09, 07:20:21 (80.232.198.20)
It could make sense. Mid-range tube amp usually have decent output transformers with relatively low resonant frequency and high leakage inductance (leading to considerable phase shift as signal freque .......
45: Tube DIY Asylum, RE: Improved Marantz 9?? (0.00)
Posted by LinuxGuru on 2017-03-23, 02:04:05 (80.232.198.20)
Quite complex schematic for a parallel push-pull (I prefer simpler design), yet it is job done very well. .......
46: Tube DIY Asylum, RE: 4P1L preamp DIY (0.00)
Posted by LinuxGuru on 2017-03-20, 08:46:52 (80.232.198.20)
Hi, Johno, Very nice and accurate build ! BTW, have you tried to move PCB located on the top of the choke and mount it in vertical position nearby ? .......
47: Tube DIY Asylum, RE: Do russian teflon capacitors lack musicality? (0.00)
Posted by LinuxGuru on 2017-02-18, 03:22:33 (83.99.228.190)
These boutique snake oil parts have nothing to do with real world price / performance ratio. Look at their web site. These super duper VCaps advertised with a ton of utterly useless blah blah blah and .......
48: Tube DIY Asylum, RE: Industry professionals? (0.00)
Posted by LinuxGuru on 2017-02-17, 11:14:45 (83.99.228.190)
That guy from Serious whatever is from another industry - fantasy land. .......
49: SET Asylum, RE: missing link? (0.00)
Posted by LinuxGuru on 2017-02-12, 07:56:30 (83.99.228.190)
Look for XJW01 LCR meter on Amazon, eBay and Aliexpress. This model seems to be discontinued. On Aliexpress they are available at around $100 but assembly is UNFINISHED, as stated in listings. I don't .......
50: SET Asylum, RE: When you get "Serious" about building SE amplifiers you get ones of these (0.00)
Posted by LinuxGuru on 2017-02-10, 15:12:22 (83.99.228.190)
> Serious SET hobbyist needs LCR meter that can measure variable inductance from 20Hz-20KHz. Certainly exists yet too expensive for hobby use. Generator, resistor and true RMS voltmeter is enough for .......
51: SET Asylum, RE: When you get "Serious" about building SE amplifiers you get ones of these (0.00)
Posted by LinuxGuru on 2017-02-10, 11:31:35 (83.99.228.190)
For a hobby Chinese products are a real budget savers. You can find on this device here: http://www.eevblog.com/forum/testgear/xjw01-auto-lcr-meter-review-($120-bench-top-lcr-meter)/ Additionally, the .......
52: SET Asylum, RE: "the STUPIDEST POST I have ever read!" (0.00)
Posted by LinuxGuru on 2017-02-06, 13:52:08 (83.99.228.190)
> All I can say is that I did hear two pair of his 2A3 amps from > different years and although they sounded good, I didn't feel they > were any better than what I've owned in the past and heard. For .......
53: SET Asylum, RE: xaudiomanx. (0.00)
Posted by LinuxGuru on 2017-02-05, 10:37:18 (83.99.228.190)
> DENNIS IS SERIOUS > Now if you want to get ahead of the game you could ask > SERIOUS questions instead of your typical JUNK science repetitive Serious question - no problem! Look at the one of th .......
54: SET Asylum, RE: xaudiomanx. (0.00)
Posted by LinuxGuru on 2017-02-05, 08:49:11 (83.99.228.190)
> Why are you picking on Dennis? I'm picking on bullocks and nonsense. > If you guys calm down and listen to what Jeff and Dennis have > been telling you..you too could build a similar design/reap the .......
55: SET Asylum, RE: xaudiomanx. (0.00)
Posted by LinuxGuru on 2017-02-05, 07:33:03 (83.99.228.190)
> Nothing! And I mean nothing! Is there to justify $18,500. > I would love to see your cost sheet to build a set of them. > The labor doesn't matter. Unless you are getting ripped off > (which I doubt .......
56: Tube DIY Asylum, RE: IXCP10M90S (0.00)
Posted by LinuxGuru on 2017-01-08, 13:44:45 (83.99.228.190)
> BTW Neither the 10m45s or the 10m90s is a MosFet. It is depleted mode mosfet (possibly BJT-cascoded) with built-in gate protection. .......
57: Tube DIY Asylum, RE: The first factory built Deuce I've ever seen.I measred the output trans imp. (0.00)
Posted by LinuxGuru on 2016-07-02, 04:24:39 (83.99.228.190)
Mike, it would be more interesting if you measure primary inductance, leakage inductance and resonant frequency. .......
58: Tube DIY Asylum, RE: Wooo-Hooo...finally scored a Cit.II OPT (0.00)
Posted by LinuxGuru on 2016-06-29, 15:00:02 (83.99.228.190)
Can you measure leakage inductance and resonant frequency of this transformer ? .......
59: Tube DIY Asylum, RE: Another video on Spectral Analysis for audio (0.00)
Posted by LinuxGuru on 2016-05-22, 01:22:04 (83.99.228.190)
1) Link to video is not shown (at least on Mozilla Firefox). 2) Pete Millet designed and made excellent sound card interface for PC card exactly for the purpose of measuring THD / IMD. http://www.pmil .......
60: Tube DIY Asylum, RE: You are right, it is working again. (0.00)
Posted by LinuxGuru on 2016-05-18, 11:23:55 (83.99.228.190)
AudioKarma and DIYAudio admins do much better job banning trolls, thus, if you look at the forum activity, you'll find much more posts, both in general and in terms of relevance. .......
61: SET Asylum, RE: Shenzhen: Made in China (0.00)
Posted by LinuxGuru on 2016-03-23, 13:44:09 (83.99.228.190)
> Dealer ,distributor markup is probably in a range of 500% ... Nope, usually around 35% - 45%, more for accessories like cables. .......
62: SET Asylum, RE: The label, Linux, the LABEL. (0.00)
Posted by LinuxGuru on 2016-03-21, 15:57:29 (83.99.228.190)
> The care taken to install the label I wouldn't shoot them for crooked label, its occasional mishap which I could easily correct and forget. However, their transformers remind me something. In pa .......
63: SET Asylum, RE: Two teasers...and more (0.00)
Posted by LinuxGuru on 2016-03-21, 12:27:16 (83.99.228.190)
> Dig the crooked label. For that, one gets to pay $21000 per pair! > Even on 10dB-more-sensitive Serenity Super-7s, they sounded > good but not anything special, so out they went. Any SET amplifier, .......
64: Tube DIY Asylum, RE: schematic question (0.00)
Posted by LinuxGuru on 2015-09-22, 10:16:50 (83.99.228.190)
Snubber for suppressing transformer ringing. .......
65: SET Asylum, RE: My 3 years to the goal of the non-compromise SET and still learning.. (0.00)
Posted by LinuxGuru on 2015-09-17, 09:54:04 (83.99.228.190)
> Q2. your transformers (specifically the two twin coil single > C core) are the two halves of the c-cores banded together? > From the photos I could not "see" the banding (if they are banded). There .......
66: SET Asylum, RE: You May Express Your Dismay (0.00)
Posted by LinuxGuru on 2015-08-27, 11:26:47 (83.99.228.190)
As the marketing company Audio Note definitely excels, hats off, there are very few enterprises which can extort so much cash & profit from mythology around quite ancient and primitive technology. If .......
67: Tube DIY Asylum, RE: Thanks for the feedback guys...... (0.00)
Posted by LinuxGuru on 2015-08-24, 13:58:40 (83.99.228.190)
You can buy metal film Panasonic or Vishay at Digikey, Farnell, or Mouser, so no much reason to pay premium price for surplus, unless you can buy a barrel of them for something close to nothing. ::: T .......
68: Tube DIY Asylum, RE: Has anyone tried any of the russkie resistors? (0.00)
Posted by LinuxGuru on 2015-08-24, 13:09:11 (83.99.228.190)
MLT (МЛТ) are fine metal film resistors, are much bigger compared to today's counterparts of equal power, and therefore, better dissipate heat. Avoid carbon film resistors of VS (BC) .......
69: Tube DIY Asylum, RE: Here's a Guy Doing Something Similar (0.00)
Posted by LinuxGuru on 2015-06-22, 10:01:44 (83.99.228.190)
There are a LOT of free and low-cost PCB design software packages. For example, this one: http://murtonpikesystems.azurewebsites.net/ 24 GBP Or freeware KiCAD. https://www.udemy.com/learn-kicad-printe .......
70: Tube DIY Asylum, RE: Here's a Guy Doing Something Similar (0.00)
Posted by LinuxGuru on 2015-06-22, 09:03:41 (83.99.228.190)
2 stacked prototyping boards, 180x220mm / 7.1x8.66". .......
71: Tube DIY Asylum, RE: Here's a Guy Doing Something Similar (0.00)
Posted by LinuxGuru on 2015-06-22, 08:59:13 (83.99.228.190)
Hi, TK, You can borrow some ideas from this device if you are keen to use CNC milling to make prototyping PCBs. http://cirqoid.com/ IMHO, for high-voltage tube circuits, this device is far from opt .......
72: Tube DIY Asylum, RE: Making Circuit Boards (0.00)
Posted by LinuxGuru on 2015-06-21, 22:48:48 (83.99.228.190)
Do you need PCB for prototyping or finished circuit ? .......
73: Tube DIY Asylum, RE: schematic program (0.00)
Posted by LinuxGuru on 2015-06-14, 07:36:15 (83.99.228.190)
LTSpice http://www.linear.com/designtools/software/ Price: priceless (freeware) You can even estimate THD %. I did this in the past, results of the simulations are very close to those I've got with th .......
74: Tube DIY Asylum, RE: 6SL7 C4S driver ... (0.00)
Posted by LinuxGuru on 2015-05-13, 10:56:42 (83.99.228.190)
> Also what is 'transfer efficiency' measured in ? in kiloBS, megaBS or even gigaBS, depending upon jump factor. .......
75: Tube DIY Asylum, RE: I finally received my gm70 Trans from Tribute. (0.00)
Posted by LinuxGuru on 2015-05-10, 08:27:35 (83.99.228.190)
> I am sorry to say but did you ever wind a transformer? I did, including PP toroids. > You try to find excuses for everything and you not actually > something of any importance. Its not an excuse, ju .......
76: Tube DIY Asylum, RE: I finally received my gm70 Trans from Tribute. (0.00)
Posted by LinuxGuru on 2015-05-10, 04:53:27 (83.99.228.190)
> If copperloss was not importand why do you think every quality > brand uses bigger cores instead of using more windings? Are they insane? Bigger core allows to reduce primary turns. BTW, copper loss .......
77: Tube DIY Asylum, RE: I finally received my gm70 Trans from Tribute. (0.00)
Posted by LinuxGuru on 2015-05-10, 04:04:00 (83.99.228.190)
> Having high copperlosses means normally that a lot of windings > is used, that means more windingcapacity and that isn't good > for the high frequency response. Not necessary, it may mean that wire .......
78: Tube DIY Asylum, RE: I finally received my gm70 Trans from Tribute. (0.00)
Posted by LinuxGuru on 2015-05-10, 01:49:34 (83.99.228.190)
> I saw finemet transformers with heavy copperloss, > less then 88% transfer. A good transformer dos >94% (0,26dB) Finemet have only Bmax = 1.25T, so in any case it will require a lot of primary turn .......
79: Tube DIY Asylum, RE: Please Help I ordered my tribute Trans and payed in full for them in november but still no trans. (0.00)
Posted by LinuxGuru on 2015-05-04, 02:08:18 (83.99.228.190)
> Remember the price of $600 each, no way you can have super > large nanocrystaline (costum or not) cores for this price level. I didn't remember exactly prices for custom Fe-based amorphous / nanocry .......
80: Tube DIY Asylum, RE: Please Help I ordered my tribute Trans and payed in full for them in november but still no trans. (0.00)
Posted by LinuxGuru on 2015-05-03, 02:03:42 (83.99.228.190)
> So what is your point? Point is that its possible to order core wound with Finemet ribbon of any reasonable size from third party, not necessary Hitachi. .......
81: Tube DIY Asylum, RE: Please Help I ordered my tribute Trans and payed in full for them in november but still no trans. (0.00)
Posted by LinuxGuru on 2015-05-02, 04:14:13 (83.99.228.190)
Finemet is a Hitachi trademark of the family of nanocrystalline alloys. They can be sold as finished cores by Hitachi or to third parties as ribbon. So even if cores made with Finemet it is not necess .......
82: Tube DIY Asylum, RE: Replace it or reject it? (0.00)
Posted by LinuxGuru on 2015-04-30, 04:17:46 (83.99.228.190)
It is RC network to suppress transformer ringing. You can exclude it if you wish as long as you don't care about square wave performance. I don't think it will lead to amplifier instability. ::: TOPIC .......
83: Tube DIY Asylum, RE: A Mercedes and a bus... (0.00)
Posted by LinuxGuru on 2015-03-15, 16:25:17 (83.99.228.190)
> Now the entertaining question is( IMO), does Dennis actually > believe the stuff he is saying? 1000% he does. .......
84: Tube DIY Asylum, RE: A Mercedes and a bus... (0.00)
Posted by LinuxGuru on 2015-03-15, 15:23:14 (83.99.228.190)
> Every time you assert the idea that there is signal that is common > to both "Hot" wires, in a music signal, you show your ignorance. Incompetence, to be precise. Like other insanely dumb "idea" to .......
85: Tube DIY Asylum, RE: Question.. Whhhaohhh (0.00)
Posted by LinuxGuru on 2015-02-17, 04:33:08 (83.99.228.190)
> Lab measurements Of Dennis Fraker's 2A3 amps. Thats all I will say. Sometimes picture worth a thousands of words. Can we see those earth shattering results of measurements? .......
86: Tube DIY Asylum, RE: What is transfer efficiency? (0.00)
Posted by LinuxGuru on 2015-02-15, 12:13:51 (83.99.228.190)
Marketing abracadabra. You can see even more extreme examples in megabuck cables and power cords advertisement. PS. Do you really take serious "theory" from someone who proposed to bias speaker cables .......
87: Tube DIY Asylum, RE: final update on 91A operating points ..... (0.00)
Posted by LinuxGuru on 2015-02-14, 11:08:01 (83.99.228.190)
> "The 2A3 amps IN SERIES drove the speaker to over 105 db SPL at > one Meter, and it was splendid-- simply awesome, and clean. > The speaker has 92 db/watt efficiency." > To cause a 92db speaker to o .......
88: SET Asylum, RE: Explain parafeed OPTs in an DHT SET amp (0.00)
Posted by LinuxGuru on 2015-02-12, 10:37:41 (83.99.228.190)
Hi, Frihed89, Parafeed output transformer is much cheaper and easier to build having the same inductance and much lower parasitic parameters. It don't need air gapped core and can fully utilize magnet .......
89: Tube DIY Asylum, RE: Listen Up....GENTS (0.00)
Posted by LinuxGuru on 2015-01-31, 03:21:12 (83.99.228.190)
> Almost ALL of the naysayers who post on this Forum, are speaking > from a reference of never hearing Dennis' amps at all, let > alone extensively, as I have. His amps' performance, over the > years, .......
90: SET Asylum, RE: How Rude of you (0.00)
Posted by LinuxGuru on 2015-01-26, 11:41:42 (83.99.228.190)
> Jeff has mentored me in building my own amp and now have what I > consider a stunning amp with breathtaking sound. We are glad you are happy with your build. > All I ask of a forum and its members .......
91: Tube DIY Asylum, RE: I think you're confused... (0.00)
Posted by LinuxGuru on 2015-01-22, 04:33:58 (83.99.228.190)
> No, not at all, but in the case of Dennis Fraker, he HAS a > credible record in engineering, over DECADES, in audio and > in the movie theatre business. My father is a scientist, so I have a clue h .......
92: Tube DIY Asylum, RE: I think you're confused... (0.00)
Posted by LinuxGuru on 2015-01-20, 09:23:45 (83.99.228.190)
> "A film cap can measure flat and wide band statically - on the > bench, but play narrow band and be somewhat frequency selective > by ear." - Dennis Fraker. May be its Mr Fraker imagination? Do you .......
93: Tube DIY Asylum, RE: Polystyrenes as coupling caps (0.00)
Posted by LinuxGuru on 2015-01-18, 05:08:35 (83.99.228.190)
> I know a lot of DIYer's suggest polystyrene in the RIAA but how > about for coupling? I used Panasonic and Cornell Dubilier as coupling caps, work great, no complains whatsoever. PS. Once I have see .......
94: Tube DIY Asylum, RE: Wish I couldn't hear the difference between caps ... (0.00)
Posted by LinuxGuru on 2015-01-18, 03:15:55 (83.99.228.190)
Hi, Garg0yle, > I have observed this forum from the sidelines for years, > it was quite difficult as a amateur beginning down this path to >sort out what the bullshit is, why there is such conflicting .......
95: Tube DIY Asylum, RE: Cost-Effective Cathode Chokes (0.00)
Posted by LinuxGuru on 2015-01-18, 03:07:59 (83.99.228.190)
It should work, especially if SE transformer have low leakage inductance. Additionally, I would shunt secondary (8 ohm tap) with 1k resistor (value should be chosen in experimental way, so primary imp .......
96: Tube DIY Asylum, RE: Measuring Chokes (0.00)
Posted by LinuxGuru on 2015-01-16, 13:14:32 (83.99.228.190)
Steve Bench have developed L-meter with DC bias capability: http://diyaudioprojects.com/mirror/members.aol.com/sbench101/#Inductance Otherwise, you have to opt for industrial unit which is quite expen .......
97: SET Asylum, RE: You live in the dark ages ......Think like a caveman, (0.00)
Posted by LinuxGuru on 2015-01-14, 23:27:32 (83.99.228.190)
> Those old theories taught in those old tube books are not high > fidelity-to-signal. > They DO NOT reproduce music RIGHT! NONE of those tube amps ever did... > Nothing built with those old, obsolete .......
98: Tube DIY Asylum, RE: Yes, a local positive feedback loop... (0.00)
Posted by LinuxGuru on 2015-01-14, 23:15:04 (83.99.228.190)
Do SPICE simulation with LTSpice. .......
99: Tube DIY Asylum, RE: Don't take offense... (0.00)
Posted by LinuxGuru on 2015-01-10, 09:34:02 (83.99.228.190)
> I know a LOT of people in audio, many I would consider to be my > friends, good people Linux Guru, and no one I know knows how to > solve the problem like Dennis did. Of course, Your friends incl. D .......
100: Tube DIY Asylum, RE: Don't take offense... (0.00)
Posted by LinuxGuru on 2015-01-10, 07:55:53 (83.99.228.190)
> Everything you're saying here is true, BUT-- and here's the rub-- > ALL capacitors are VERY flawed devices. And I do mean ALL of them. ..... As usual, totally incompetent statement, pitiful attempt .......
101: SET Asylum, RE: Three questions, if you will, please (0.00)
Posted by LinuxGuru on 2015-01-01, 06:38:59 (83.99.228.190)
> best sounding SET I've ever heard and also built is my PSE 4P1L amp. > No cathode bypass caps, no signal caps, all filament bias, > all transformer coupled. Hi, Andy! Have you tried to build parafe .......
102: SET Asylum, RE: STOP THE COMMERCIAL PROMOTION (0.00)
Posted by LinuxGuru on 2015-01-01, 04:35:23 (83.99.228.190)
> I am trying to WAKE the "likes of YOU" UP, to let you come to > understand that the SUN does not revolve around the EARTH in > your audio design approach. You, and many others, design for > the wron .......
103: SET Asylum, RE: BB Proof pictures (0.00)
Posted by LinuxGuru on 2014-12-26, 02:33:17 (83.99.228.190)
A really clever hardware hack with chassis construction ! .......
104: Tube DIY Asylum, RE: Christmas presents - Heaven and Hell! (0.00)
Posted by LinuxGuru on 2014-12-21, 02:33:35 (83.99.228.190)
> Hell - another pair of 8" Mark Audio Alpairs Hi, Caucasian Blackplate, What exactly is wrong with these speakers? They have been on my top list for next purchase but you alarmed me. .......
105: Tubes Asylum, RE: Going from KT88 to KT150, what to expect? (0.00)
Posted by LinuxGuru on 2014-12-14, 13:07:10 (83.99.228.190)
You won't gain more power by using KT150 with stock transformer and power supply instead of KT88, INHO better to invest in high-quality KT88, like Genalex Golden Lion. .......
106: SET Asylum, RE: Maxing stock chokes and DHT filament transformers (0.00)
Posted by LinuxGuru on 2014-12-07, 10:43:22 (83.99.228.190)
> And that's when large, high quality wire and close-coupled > "bird's nest" wiring makes a whopping difference-- when the > leading edge of a pulse hits all of the components in the amp. > The questi .......
107: Tubes Asylum, RE: 6S19P-V (0.00)
Posted by LinuxGuru on 2014-12-04, 14:31:12 (83.99.228.190)
> Actually I was thinking about using it in a preamp to drive a > tube like a 350B, 6L6, EML30A etc.! So how do you think it > would sound in this application? 6S19P is not good tube for this applicat .......
108: Tubes Asylum, RE: 6S19P-V (0.00)
Posted by LinuxGuru on 2014-12-03, 08:18:05 (83.99.228.190)
Hi, thetubeguy1954, This is one of the most favorite tube among Russian audiophiles, along with 6S33S, 6S4S, 6P3S-E and 4P1L. Use several pcs in parallel in order to get reasonable output power. ::: T .......
109: Tube DIY Asylum, RE: Bias Protection (0.00)
Posted by LinuxGuru on 2014-11-30, 02:41:20 (83.99.228.190)
Hi, Triode Kingdom, > This is a sticky problem, one I'm still wrestling with. I've > thought about using 100mA fuses at the cathodes, but that only > protects from a total bias failure. If the bias su .......
110: SET Asylum, RE: Is this 300b too good to be true? (0.00)
Posted by LinuxGuru on 2014-11-27, 22:59:44 (83.99.228.190)
Very nice build quality for a reasonable, affordable price. IMHO good value for its money. .......
111: SET Asylum, RE: 2A3 Operating Points (0.00)
Posted by LinuxGuru on 2014-11-25, 11:57:00 (83.99.228.190)
> When I have designed amplifiers previously, I relied 100% on > hand written calculations and my TI-85 pocket calculator... > this seems to add a whole new dimension to what is possible. Another hint .......
112: SET Asylum, RE: 2A3 Operating Points (0.00)
Posted by LinuxGuru on 2014-11-25, 11:25:16 (83.99.228.190)
Don't forget about LTSpice, too ! Great tool before start to breadboard your amplifier. .......
113: SET Asylum, RE: 2A3 Operating Points (0.00)
Posted by LinuxGuru on 2014-11-25, 11:09:37 (83.99.228.190)
Hi, maxhifi, Here is online operating pont calculator written by gsmok: http://www.trioda.com/tools/triode.html and here discussion on diyaudio.com http://www.diyaudio.com/forums/tubes-valves/260908-t .......
114: Tube DIY Asylum, RE: Anyone used a TIG Welder? (0.00)
Posted by LinuxGuru on 2014-11-21, 13:42:28 (83.99.228.190)
Hi, Triode_Kingdom, Use epoxy like JB Weld, forget about tig weld, it is not necessary in this case. .......
115: Tube DIY Asylum, RE: any one here build the KT120pp power amp? (0.00)
Posted by LinuxGuru on 2014-11-19, 08:40:49 (83.99.228.190)
Hi, caffeinator, Any KT88 based amp will work with KT120 if your output and power transformers are up to the task. My favorite PP amp is so called "88-50", by Ian Heath and G R Woodville; schematic an .......
116: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by LinuxGuru on 2014-11-18, 08:21:54 (83.99.228.190)
Excellent examples of point-to-point wiring can be seen here: http://www.audiokarma.org/forums/showthread.php?t=571478 .......
117: SET Asylum, RE: Absolute Sound and All That Jazz (0.00)
Posted by LinuxGuru on 2014-11-18, 05:00:36 (83.99.228.190)
> I figured the parts for a PAIR even with EML 2A3s would be > somewhere between $3300 and $3800 Hi, GSH, You can be on budget if you build 4P1L based SET with filament bias and no cathode bypass capa .......
118: Tube DIY Asylum, RE: any one here build the KT120pp power amp? (0.00)
Posted by LinuxGuru on 2014-11-18, 04:30:38 (83.99.228.190)
I run them in UL, and in UL with CFB. If you use 3.5K opt you will get the same output power as KT55/6550. .......
119: SET Asylum, RE: Yup, really ....... (0.00)
Posted by LinuxGuru on 2014-11-17, 12:36:46 (83.99.228.190)
I already replied you several times on different threads, you just don't listen anyone except yourself and DF. I have not heard Serious Stereo DC 2A3, neither yours, and not going to waste a time even .......
120: Tube DIY Asylum, RE: any one here build the KT120pp power amp? (0.00)
Posted by LinuxGuru on 2014-11-17, 06:54:26 (83.99.228.190)
B+ around 500V, 2.0 - 2.2K output transformer. Right now I have 3.3K - 3.9K opts only, so I get only 60 - 70W of output power. .......
121: SET Asylum, RE: Mystery has an end, in this case, enough is enough (0.00)
Posted by LinuxGuru on 2014-11-17, 02:24:36 (83.99.228.190)
> I know exactly what this is. I will tell you if you can't > guess correctly. At first I thought this is DrLowMu creature. Typical amateur build, definitely not the worst one. Nothing worth 5-digit p .......
122: SET Asylum, RE: Show Me! (0.00)
Posted by LinuxGuru on 2014-11-16, 04:33:33 (83.99.228.190)
> I have another reason why I took up for DF. It's because the > men of his generation won't be around forever, and much of > their knowledge and experience will be lost with them. You can find a lot .......
123: SET Asylum, RE: Yup, really ....... (0.00)
Posted by LinuxGuru on 2014-11-15, 09:51:24 (83.99.228.190)
> I have heard most all the vintage amps. > You have never heard Dennis' amps, in many venues, as I have, > have you?? Probably not once for you !! You are talking > unsubstantiated, only guessing, wi .......
124: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by LinuxGuru on 2014-11-15, 05:00:51 (83.99.228.190)
Hi, GSH, > And after tearing them apart, and changing the driver to a CCS > loaded low mu type (used formerly) and then comparing on the > same chassis between a parafeed output and a regular gapped O .......
125: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by LinuxGuru on 2014-11-15, 03:50:15 (83.99.228.190)
> Can someone describe the difference , in sound , between > these two tubes in an otherwise equal SE circuit ? > Thank You > saki70 Its too personal and depends upon too many factors, so you have to .......
126: SET Asylum, RE: Really? (0.00)
Posted by LinuxGuru on 2014-11-15, 03:41:31 (83.99.228.190)
> That was Saul Marantz, not Sal. Anyhow, I have used all of those > amps, have modified them when necessary, and have installed and > lived with them over time, and have used a whole lot more. > Thos .......
127: SET Asylum, RE: Difference between EL-34 & 300B sound in SE circuit (0.00)
Posted by LinuxGuru on 2014-11-12, 11:18:41 (83.99.228.190)
> What is the problem with a pentode or tetrode strapped as a > "triode"? There is s timing difference between the two grids-- > the distances between plate to grid and cathode to grid.. This messes > .......
128: SET Asylum, RE: McIntosh MI-200 amplifier (0.00)
Posted by LinuxGuru on 2014-11-06, 13:08:11 (83.99.228.190)
McIntosh Mi200 was designed and built by experienced and skillful specialists, its a pity historical piece of expensive vintage equipment was crippled by means of meaningless tweaking. Apart from repl .......
129: Tube DIY Asylum, RE: YOUR solution ..... (0.00)
Posted by LinuxGuru on 2014-11-03, 09:32:03 (83.99.228.190)
> I have a solution for you Linix Guru. You have free will. > Whenever you see a post written by me, "drlowmu", do NOT read it !! > If you do not accept my reality, that is FINE with me I would be gla .......
130: Tube DIY Asylum, RE: Credibility? Really? (0.00)
Posted by LinuxGuru on 2014-11-03, 04:42:28 (83.99.228.190)
> Not once - not even once - have you ever posted the performance > of anything you build. Not THD, not frequency response, not > gain, nothing. In fact, you can't even discuss these fundamental > iss .......
131: Shady Lane, RE: I could use some advice (0.00)
Posted by LinuxGuru on 2014-10-05, 12:58:44 (83.99.228.190)
Hi ! Any news? Did seller returned full amount or still promising something? .......
132: Tube DIY Asylum, RE: Feedback on possible amp topology (0.00)
Posted by LinuxGuru on 2014-09-29, 13:43:57 (83.99.228.190)
Anyone have tried combination of filament cathode bias and small amount of fixed bias (e.g. -10V)? This would allow to reduce power dissipation of cathode resistor. I have seen some reports that DHT w .......
133: Tube DIY Asylum, RE: Feedback on possible amp topology (0.00)
Posted by LinuxGuru on 2014-09-28, 23:13:29 (83.99.228.190)
This is something I have plan to build, too. Please keep us updated. BTW, I would suggest to replace plate choke with cascoded depleted mode mosfets or penthode CSS. .......
134: Tubes Asylum, RE: Citation II restoration progress (0.00)
Posted by LinuxGuru on 2014-09-12, 14:02:18 (83.99.228.190)
Impressive work ! .......
135: Tube DIY Asylum, RE: What have they done (0.00)
Posted by LinuxGuru on 2014-09-12, 04:12:37 (83.99.228.190)
> other than change the packaging? Taking into account amount of marketing bluff (from product's site), sure for 99% that these are just repackaged items. Just think about this - "specially developed .......
136: Tube DIY Asylum, RE: New Audio Note Electrolytic Audio Capacitors coming soon (0.00)
Posted by LinuxGuru on 2014-09-11, 11:58:03 (83.99.228.190)
I use Rubicon electrolytes (original, not repackaged), really good caps. No different from comparable like Epcos or Panasonic. > Even though these capacitors represent the starting level in our > new .......
137: SET Asylum, RE: Looking for 845 tube Output transformers. (0.00)
Posted by LinuxGuru on 2014-07-06, 02:24:39 (83.99.228.190)
Insulation strength for 1kV B+ 845 output transformer should be around 3kV at least. Technically, not a problem. IMHO any transformer from reputable manufacturer have these design spec in mind. ::: TO .......
138: Tube DIY Asylum, RE: Please Help I ordered my tribute Trans and payed in full for them in november but still no trans. (0.00)
Posted by LinuxGuru on 2014-05-25, 09:10:26 (83.99.228.190)
You have to wait, for a VERY LONG time ! Here is another thread with similar problem. http://www.audioasylum.com/cgi/t.mpl?f=tubediy&m=204968 .......
139: Tube DIY Asylum, RE: Please continue (0.00)
Posted by LinuxGuru on 2014-05-14, 10:40:11 (83.99.228.190)
> I had metal film resistors in there, and let him listen to it for > a couple cuts, then quickly soldered in the same value Takman > carbon film resistors, and replayed the cuts. In the first few > s .......
140: Tube DIY Asylum, RE: SE 7B4 DC 2A3 : CCS mu output DN2540 ... (0.00)
Posted by LinuxGuru on 2014-05-13, 12:24:34 (83.99.228.190)
I think you should change operation point of tube, e.g. slightly increase anode current. BTW, before soldering real circuit, it is a good idea to simulate it in LTSpice. THD simulation in LTSpice is s .......
141: Tube DIY Asylum, RE: much confusion for builders ... (0.00)
Posted by LinuxGuru on 2014-05-11, 15:52:43 (83.99.228.190)
> I was going to investigate Drlowmu's SE 7B4 DC 2A3 circuit > again since I had the parts, but now it seems he has changed > his idea of what the "best" PS filter is again. >If he is trying to replic .......
142: Tube DIY Asylum, RE: response from Sophia Electric (0.00)
Posted by LinuxGuru on 2014-04-23, 10:16:23 (83.99.228.190)
> Traditionally, North America amplifier makers and industry > insiders would not repair another US maker's amplifier to > avoid quarreling and potential lawsuit. Those who did would > do it undergrou .......
143: Tube DIY Asylum, RE: PC measurement system : ESI Juli 192KHz sound card ... (0.00)
Posted by LinuxGuru on 2014-03-12, 14:39:00 (83.99.228.190)
Good idea, and fine card for this purpose. Pete Millett sound card interface would be a nice and extremely useful addition. .......
144: Tube DIY Asylum, RE: Where to get 200H plate chokes (0.00)
Posted by LinuxGuru on 2014-02-18, 12:54:25 (83.99.228.190)
Apart from massive and expensive plate choke, you can take into account another type of active load - CSS, based on depleted mode mosfets. You will have much better result for much lower cost, size an .......
145: Tube DIY Asylum, RE: Cap values (0.00)
Posted by LinuxGuru on 2014-01-26, 10:16:26 (83.99.228.190)
> DFs values mostly summed up here, by him, on the forum. > many of his proprietary ideas he's posted here. > http://www.audioasylum.com/forums/tubediy/messages/21/217269.html Take a look at this nons .......
146: Tube DIY Asylum, RE: Tango to cease making transformers? (0.00)
Posted by LinuxGuru on 2014-01-17, 12:46:14 (83.99.228.190)
There is a thread on diyaudio about Tabgo. Looks like Tango team is retired because of age. .......
147: Tube DIY Asylum, RE: Unclear voltage of the newly received amp (0.00)
Posted by LinuxGuru on 2014-01-07, 13:37:05 (83.99.228.190)
Connect it to step-down 220->110V transformer, and look if it will work normally. If yes, you have 110V version, if not, 220V. .......
148: Tube DIY Asylum, RE: Russian ssg Silver Mica Capacitors? (0.00)
Posted by LinuxGuru on 2013-12-24, 15:34:22 (83.99.228.190)
SSG and KSG silver mica capacitors are one of the best caps ever made. .......
149: Tubes Asylum, RE: Denied assess to Tubes Asylum (0.00)
Posted by LinuxGuru on 2013-12-16, 04:55:02 (83.99.228.190)
I had the same problem, admins blocked certain IP ranges because of spambots. Contact Bored, he will solve this issue. .......
150: General Asylum, RE: Attn Admin - Problem accessing AudioAsylum from my home network (0.00)
Posted by LinuxGuru on 2013-12-13, 23:57:56 (80.232.198.20)
Hi, Bored, I've sent you PM with my IP. Thanks in advance. .......
151: General Asylum, Attn Admin - Problem accessing AudioAsylum from my home network (0.00)
Posted by LinuxGuru on 2013-12-13, 00:01:11 (80.232.198.20)
Anyone have experienced this problem in last 2 weeks accessing AudioAsylum forums? http://www.audioasylum.com/cgi/etv.mpl Access denied Strange enough, this is only happen when I access AudioAsylum fr .......
152: Tubes Asylum, RE: KT-88 On A Budget (0.00)
Posted by LinuxGuru on 2013-11-02, 07:45:30 (83.99.228.190)
Reissue of Genalex Golden Lion KT88. Don't know what the USA price is, but tubes are excellent. .......
153: Tube DIY Asylum, RE: All about Transformer Cores - Materials, Geometry, Gaps, etc. (0.00)
Posted by LinuxGuru on 2013-10-30, 11:23:33 (83.99.228.190)
Hi, Dave, PM me I'll send the whole PDF. .......
154: Tube DIY Asylum, RE: All about Transformer Cores - Materials, Geometry, Gaps, etc. (0.00)
Posted by LinuxGuru on 2013-10-29, 13:50:04 (83.99.228.190)
Dave, do you refer to so called step-lap joints? This technique is being developed to provide distributed air gap for amorphous tape wound cores used for transformers from several kW to hundreds of .......
155: Tube DIY Asylum, RE: All about Transformer Cores - Materials, Geometry, Gaps, etc. (0.00)
Posted by LinuxGuru on 2013-10-29, 12:20:01 (83.99.228.190)
> We first need to agree on the simple model before we move on > and in its simplest form a continuous tape toroid still has a gap. > Until everyone can see and identify the nature of the gap in a > t .......
156: Tube DIY Asylum, RE: Experimenting with Output Transformers (0.00)
Posted by LinuxGuru on 2013-10-29, 05:30:00 (83.99.228.190)
> The key thing to note here is that a distributed gap behaves > very differently than an discrete gap. I'll gladly discuss > this more if anyone is interested. Dave, you are very welcome to do so. I .......
157: Tube DIY Asylum, All about Transformer Cores - Materials, Geometry, Gaps, etc. (0.00)
Posted by LinuxGuru on 2013-10-29, 05:26:43 (83.99.228.190)
Thread is actually inspired by Dave Slagle. It is open discussion about everything related to transformer cores. > by Dave Slagle > The key thing to note here is that a distributed gap behaves > very .......
158: Tube DIY Asylum, RE: Experimenting with Output Transformers (0.00)
Posted by LinuxGuru on 2013-10-28, 13:05:55 (83.99.228.190)
Due to unavoidable gaps between lamination EI transformers have so called quasi-distributed air gap by default, so even without explicitly made gap they are more tolerant to DC bias then gap-less C co .......
159: Tube DIY Asylum, RE: query about transformers (0.00)
Posted by LinuxGuru on 2013-10-17, 22:49:17 (83.99.228.190)
1) Audio transformers need sliced (sectioned) windings in order to reduce leakage inductance. 2) Even if sectioning won't required, what is the purpose of electrostatic shield in wide-band transformer .......
160: Tube DIY Asylum, RE: Step-down autotransformer (0.00)
Posted by LinuxGuru on 2013-09-28, 15:18:32 (83.99.228.190)
Also, look at the place called "baraholka". .......
161: Tube DIY Asylum, RE: Step-down autotransformer (0.00)
Posted by LinuxGuru on 2013-09-28, 06:56:09 (83.99.228.190)
Many local electric shops (which sell radio parts) carry auto-transformers, price is around 50 Euro. .......
162: Tube DIY Asylum, RE: Linear Audio Magazine- Anyone buying it? (0.00)
Posted by LinuxGuru on 2013-09-07, 15:30:07 (83.99.228.190)
Really unique, and one of the best magazines published today. .......
163: Tube DIY Asylum, RE: I think I see this now after reading Steve;s article he posted a few times. (0.00)
Posted by LinuxGuru on 2013-08-25, 15:17:29 (83.99.228.190)
BTW, type of this amp could be better described as long-tail (differential) transformer loaded output stage, not "self inverting something", LTP is actually an inverter (look for example at Mullard 52 .......
164: Tube DIY Asylum, RE: Please suggest alternative to the LM 317 (0.00)
Posted by LinuxGuru on 2013-08-25, 15:06:17 (83.99.228.190)
> I didn't find the LM317 to be that offensive either but > there are definitely better ones for our purpose IXYS 10M45S or 10M90S. .......
165: Tube DIY Asylum, RE: I think I see this now after reading Steve;s article he posted a few times. (0.00)
Posted by LinuxGuru on 2013-08-25, 13:33:21 (83.99.228.190)
Mike, actually this is long-tail differential amplifier loaded with transformer. It amplifies the difference between two inputs. (input voltage #1 - input voltage #2) x gain = output voltage. In our c .......
166: Vintage Asylum, RE: Look at all these schematics Mikey just found for us. (0.00)
Posted by LinuxGuru on 2013-08-20, 11:22:52 (83.99.228.190)
Sorry, link doesn't work, neither yesterday neither today. PS. Snapshot is available via wayback machine. http://web.archive.org/web/20120822000805/http://www.ys-audio.com/c_wcrut.htm .......
167: Tube DIY Asylum, RE: es, a choke has both DCR and impedance but those are not always added to the output impedance of the supply. (0.00)
Posted by LinuxGuru on 2013-08-16, 14:28:02 (91.182.103.113)
I just launched PSUD2 on Linux with Wine, looks like its working, should be the same on Intel Mac. PSUD2 is very specialized program, too few people use it and not reported to Wine HQ as compatible. : .......
168: Tubes Asylum, RE: Thanks Eli (0.00)
Posted by LinuxGuru on 2013-08-14, 14:28:21 (77.229.88.70)
> Have you actually listened to an amplifier that was designed > and manufactured to be used with the TS KT120 output tubes I used KT120 instead of KT88/6550. There were no increase of output power, s .......
169: Tube DIY Asylum, RE: es, a choke has both DCR and impedance but those are not always added to the output impedance of the supply. (0.00)
Posted by LinuxGuru on 2013-08-14, 14:22:15 (77.229.88.70)
You can use Wine and Wineskin front-end in order to run LTSpice, PSUD, and many other software programs on Intel-based Mac. http://wineskin.urgesoftware.com/ LTSpice works fine with Wineskin, but you .......
170: Tubes Asylum, RE: Thanks Eli (0.00)
Posted by LinuxGuru on 2013-08-14, 01:32:47 (77.229.88.70)
I used Tung-Sol KT120 tubes in one of my PP amps. In spite of odd curves they sounded nice. .......
171: SET Asylum, RE: Nanocrystaline finemet cores in OPT or interstage transformers (0.00)
Posted by LinuxGuru on 2013-08-13, 10:32:53 (77.229.88.70)
1) You can take core loss data/permeability curve and other properties from the data sheet of the respective alloy/manufacturer. 2) Winding transformers using core materials other then grain oriented .......
172: SET Asylum, RE: Nanocrystaline finemet cores in OPT or interstage transformers (0.00)
Posted by LinuxGuru on 2013-08-11, 01:35:20 (77.229.88.70)
1) Very low core loss to the frequencies up to 500KHz (with special insulating coating applied), very low distortions, flat permeability curve. 2) For interstage transformer Fe or Co based nanocrystal .......
173: SET Asylum, RE: It is so obvious we can build stuff so much better for a fraction of the price. (0.00)
Posted by LinuxGuru on 2013-07-28, 08:04:13 (83.99.228.190)
> All good points , I just remain unconvinced that "we can build > stuff so much better for so much less" I was not able to save a > lot on DIY and I think, looking trough saving perspective I'd > be .......
174: SET Asylum, RE: It is so obvious we can build stuff so much better for a fraction of the price. (0.00)
Posted by LinuxGuru on 2013-07-28, 01:28:53 (83.99.228.190)
> Really? Since when? Most of friendly dealers who are always faced > with such DIY via commercial "shootouts" usually only laugh on the > side in order of not offending DIY guy (there is 0.1% chance .......
175: SET Asylum, RE: Looking for a DIY builder to collaborate with, and mentor, me (0.00)
Posted by LinuxGuru on 2013-07-27, 12:20:50 (83.99.228.190)
I would suggest to buy a kit, build it, and then take reusable parts (e.g. transformers) for next your own design. .......
176: Tweakers' Asylum, RE: Excellent....Thanks (0.00)
Posted by LinuxGuru on 2013-07-23, 11:06:50 (83.99.228.190)
> Your suggestions can easily breathe new life into older CD Players. Trash it and vice versa. .......
177: SET Asylum, RE: How does "negative" feedback work in an electronic circuit (0.00)
Posted by LinuxGuru on 2013-07-23, 10:30:11 (83.99.228.190)
> Would it be appropriate to say a unit that consists of more > non-linear tubes needs more feedback? Compared to an amp with > more linear tubes? No definitive answer, unfortunately. More linear tube .......
178: Tube DIY Asylum, RE: Some more questions about replacing electrolytics + 1 more (0.00)
Posted by LinuxGuru on 2013-07-20, 03:07:14 (83.99.228.190)
I use low-ESR Panasonic or Rubicon, don't see any reason for paying BlackGate discontinued long time ago. If that technology would be really so valuable it would be manufactured today for sure. ::: TO .......
179: SET Asylum, RE: Does this matter to you? (0.00)
Posted by LinuxGuru on 2013-07-20, 02:59:27 (83.99.228.190)
> That the audio press almost completely ignores both commercial and > DIY SET/DHT equipment,high efficiency speakers? Most commercial publications can't cash on advertisement with DIY products, so th .......
180: SET Asylum, RE: People that listen to music vs... (0.00)
Posted by LinuxGuru on 2013-07-19, 12:34:08 (83.99.228.190)
> I get the feeling at times that some audiophiles have an > almost theological need to believe that the workings of their > amplifiers lie beyond the realm of scientific inquiry. An > amplifier is no .......
181: SET Asylum, RE: A good layman explanation of feedback. (0.00)
Posted by LinuxGuru on 2013-07-15, 12:14:50 (83.99.228.190)
> Systems without negative feedback tend to sound better - even > in blind listening sessions than systems with negative feedback - > which tend to sound indistinguishable. The truth is there are no c .......
182: SET Asylum, RE: SET vs OTL (0.00)
Posted by LinuxGuru on 2013-07-14, 09:32:12 (83.99.228.190)
> Why would anyone want to take a signal from the OUTPUT stage of > an amplifier, ( which has TAKEN A CERTAIN TIME to pass through > the amplifier ), and MIX it at the INPUT STAGE with the freshly > i .......
183: Amp/Preamp Asylum, RE: Serious Stereo 2A3 amps (0.00)
Posted by LinuxGuru on 2013-07-10, 13:52:55 (83.99.228.190)
> The PROBLEM with DIY I know is this : NO ONE , myself included, > has been DIY-able to come close, let alone beat Dennis' build > implementations, particularly the most recent ones, which are > spot .......
184: Amp/Preamp Asylum, RE: These Lamm 2.1 mono block amps have peaked my curiosity quotient once again (0.00)
Posted by LinuxGuru on 2013-07-09, 04:38:18 (83.99.228.190)
Pricing of boutique business doesn't have anything common with logic or real value. BTW, $20,000 cable is nowhere better then $30,000 amplifier. .......
185: Tube DIY Asylum, RE: Greenvalves 300B SMPS Power Supply (0.00)
Posted by LinuxGuru on 2013-06-29, 01:33:04 (83.99.228.190)
SMPS is not a bad idea for tube/valve amplifier. There should be no sound quality degradation if SMPS don't radiate much of HF noise. However, the implementation you pointed too is awkward to say at l .......
186: Tube DIY Asylum, RE: Out of curiousity (0.00)
Posted by LinuxGuru on 2013-06-23, 14:16:22 (83.99.228.190)
> but what if you are looking for specific values? SGM, KSG, and SSG available in huge variety of values, sometimes really odd like 499, 3095, or 9610 pF, with the precision up to 0.3%. .......
187: Tube DIY Asylum, RE: Out of curiousity (0.00)
Posted by LinuxGuru on 2013-06-23, 12:59:19 (83.99.228.190)
> where do you source your silver micas these days? I use surplus Russian silver mica caps - SGM, KSG, SSG, K31-11, KSO. The first four are preferable, KSO I don't like. SGM are hermetically sealed in .......
188: Tube DIY Asylum, RE: power supply choke question (0.00)
Posted by LinuxGuru on 2013-06-16, 01:50:15 (83.99.228.190)
Please note there are two "H" - one is magnetizing force, measured in Oersteds, and another Henry, unit of measurement of inductance L. .......
189: Tube DIY Asylum, RE: power supply choke question (0.00)
Posted by LinuxGuru on 2013-06-16, 01:36:51 (83.99.228.190)
Do you mean DC fixed or distributed air gap choke for power supply CLC/LCL filter? If so, there should be almost no difference. H = 0.4 * pi * N * I / Lm H - magnetizing force N - number of turns I - .......
190: Critic's Corner, RE: My point about that was that I have seen more questionable writing that could be traced to animus than to amoré.. (0.00)
Posted by LinuxGuru on 2013-05-18, 10:26:31 (83.99.228.190)
> Back when I was at TAS, one of the self-important poobahs there > commented (in an email, not in the magazine), upon looking at a > photograph of Wilson Benesch's ACT One loudspeaker, that the > pho .......
191: Critic's Corner, RE: The reviewers should be aloof (0.00)
Posted by LinuxGuru on 2013-05-18, 06:04:42 (83.99.228.190)
> I would suggest the reviewers go buy stuff from a store just > like all of us and review and publish with warts and all. Any publishing house would be a bankrupt long before first issue if they do s .......
192: Tube DIY Asylum, RE: Can anyone suggest the most common cathode feedback winding ratio? (0.00)
Posted by LinuxGuru on 2013-04-27, 15:47:28 (83.99.228.190)
> I'd try researching McIntosh for this info. If anyone ever did it right, > it would be them. Maybe someone here has the inside scoop. McIntosh has unity coupled circuit, 50%/50% ratio, it requires q .......
193: Tube DIY Asylum, RE: Can anyone suggest the most common cathode feedback winding ratio? (0.00)
Posted by LinuxGuru on 2013-04-27, 08:52:50 (83.99.228.190)
If you will use KT88/6550/KT120, your UL + CFB .......
194: Tube DIY Asylum, RE: Can anyone suggest the most common cathode feedback winding ratio? (0.00)
Posted by LinuxGuru on 2013-04-27, 02:01:37 (83.99.228.190)
8% - 15%, I used 8% on custom build output opts. Running amplifier in UL+CFB produces distortion spectrum very close to triode mode. .......
195: Tube DIY Asylum, RE: Is Svetlana Still Standing? (0.00)
Posted by LinuxGuru on 2013-04-07, 10:16:13 (83.99.228.190)
Trademarking "Svetlana" is a ridiculous action by any means, no matter who did that. This is very common female Russian name, meaning literally "bright, shiny". .......
196: Tube DIY Asylum, RE: Is Svetlana Still Standing? (0.00)
Posted by LinuxGuru on 2013-04-07, 07:59:21 (83.99.228.190)
Svetlana factory in St.Petersburg is a part of very large industrial state owned conglomerate - OAO Rossijskaja Elektronika, consisting of 110 different factories and companies, many of which are rela .......
197: Tube DIY Asylum, RE: (0.00)
Posted by LinuxGuru on 2013-04-06, 03:26:41 (83.99.228.190)
I use toroids since first tube amp I built, run just slightly warm, without any audible buzzing noise. If you have problems with noisy AC line, use common mode choke on primary side. Also, I would sug .......
198: Tube DIY Asylum, RE: How difficult/dangerous is it to machine aluminum? (0.00)
Posted by LinuxGuru on 2013-03-26, 09:38:13 (83.99.228.190)
Ask any local shop which makes ad stands, they may have laser, water abrasive or plasma metal cutter. Cheap and fast. .......
199: Tube DIY Asylum, RE: A very bad idea (0.00)
Posted by LinuxGuru on 2013-03-17, 08:48:00 (83.99.228.190)
> Capacitors are by far the sorriest sounding devices ever invented > to use in the presence of audio signals-- if they're used in series > with an audio signal. Another piece of sheer nonsense. If it .......
200: Critic's Corner, RE: Re Pulley for mmf-7 turntable (0.00)
Posted by LinuxGuru on 2013-03-03, 03:28:12 (83.99.228.190)
> Sorry, but you have no understanding of turntable design or > drive principles. > Belt drive is one of the better designs for turntable drives > and platters do not need a groove, and wouldn't funct .......
201: Critic's Corner, RE: Re Pulley for mmf-7 turntable (0.00)
Posted by LinuxGuru on 2013-03-02, 06:47:59 (83.99.228.190)
Is this removable pulley on left bottom corner which drives turntable platter disk, or just 45 rpm adaptor? This pulley cost close to nothing compared to the cost of turntable, I'm working quite a lot .......
202: Tubes Asylum, RE: Create Audio / Synergy...........Are 6N8S pin compatible with 6SN7's ? (0.00)
Posted by LinuxGuru on 2013-02-17, 07:34:47 (83.99.228.190)
> I always thought they sounded dreadful. I have complete opposite experience in 2 different schematics, improved Williamson and floating paraphase - push pull. However, I assume that they may not so .......
203: Tubes Asylum, RE: Create Audio / Synergy...........Are 6N8S pin compatible with 6SN7's ? (0.00)
Posted by LinuxGuru on 2013-02-17, 01:37:49 (83.99.228.190)
Yes, they are 100% pin compatble! .......
204: Tubes Asylum, RE: Create Audio / Synergy Hifi tubes = Big Disappointment (0.00)
Posted by LinuxGuru on 2013-02-16, 03:05:17 (83.99.228.190)
Take NOS Russian 6N8S, sound excellent, cost close to nothing. .......
205: Tube DIY Asylum, RE: My 1625 Amplifier (0.00)
Posted by LinuxGuru on 2013-02-09, 03:10:08 (83.99.228.190)
Very nice build. Power and output transformers are not aligned on the same line, so there nothing to worry about low-frequency radiation/hum. Output tubes also placed on reasonable distance from outpu .......
206: Critic's Corner, RE: The reason I rarely post on Audio Asylum (0.00)
Posted by LinuxGuru on 2013-01-13, 04:27:48 (83.99.228.190)
> I wouldn't call a $20,000 amplifier high priced if it costs $13,000 > to build and performs better than a $40,000 amp. Solid state amplifier may cost $13,000 to design but certainly not $13,000 to b .......
207: Tube DIY Asylum, RE: OPT distortion cancellation w 2x SE OPT per channel? (0.00)
Posted by LinuxGuru on 2013-01-06, 06:06:36 (83.99.228.190)
Hi, Shane, There is a number of sources where you can find THD calculation formulas for grain oriented cold rolled steel (GOSS), for example in the books written by Tsykin "Low Frequency Transformers" .......
208: Tube DIY Asylum, RE: OPT distortion cancellation w 2x SE OPT per channel? (0.00)
Posted by LinuxGuru on 2013-01-04, 04:34:32 (83.99.228.190)
Shane, you can use amorphous or nanocsystalline core transformer in order to reduce distoritions. This is somehwat simpler and IMHO more effective then usage of 2 transformers. .......
209: Tube DIY Asylum, RE: OPT distortion cancellation w 2x SE OPT per channel? (0.00)
Posted by LinuxGuru on 2013-01-01, 11:27:09 (83.99.228.190)
> In Push/Pull operation, one can greatly reduce the distortions > and audibly improve the performance of such an amplifier by > applying CMR-- Common-Mode-Rejection traps What are these misterious "C .......
210: Tube DIY Asylum, RE: OPT distortion cancellation w 2x SE OPT per channel? (0.00)
Posted by LinuxGuru on 2012-12-30, 12:06:30 (83.99.228.190)
> OK-- what does CMR do? CMR shorts-out noise, hum, > AND MUSIC-- but not all of it. > because CMR is eliminating a lot of musical info., rendering > what is left-- super cleaned-up. TubeWrangler, you .......
211: Vintage Asylum, Q: Solid Electrolyte Aluminium Capacitors in Signal Path (0.00)
Posted by LinuxGuru on 2012-12-22, 08:42:05 (83.99.228.190)
Hi ! Anyone have tried to replace conventional electrolytics with solid electrolyte MnO2 aliminium capacitors in audio signal path? I meant solid electrolyte MnO2 aliminium, not tantalum or niobium. U .......
212: Tube DIY Asylum, Q: Solid Electrolyte Aluminium Capacitors in Signal Path (0.00)
Posted by LinuxGuru on 2012-12-22, 08:41:16 (83.99.228.190)
Anyone have tried to replace conventional electrolytics with solid electrolyte MnO2 aliminium capacitors in audio signal path? I meant solid electrolyte MnO2 aliminium, not tantalum or niobium. Useful .......
213: Tube DIY Asylum, RE: Please define "superconductor" wiring (0.00)
Posted by LinuxGuru on 2012-12-20, 15:02:34 (83.99.228.190)
> You bet he has analyzed it, and it was done in a very well equipped > University Electronic Engineering Laboratory. I heard all about it as > it happened. It was fascinating to hear the results. > I .......
214: Tube DIY Asylum, RE: IMHO (0.00)
Posted by LinuxGuru on 2012-12-20, 04:53:23 (83.99.228.190)
I think there is an excellent place for "modern" low DCR power supplies, Tube Wrangler theories, and it is not far away, it is right here, on AudioAsylum. This sacred shrine of knowledge called Cocnut .......
215: Tube DIY Asylum, RE: Please define "superconductor" wiring (0.00)
Posted by LinuxGuru on 2012-12-20, 04:45:54 (83.99.228.190)
> Properly designed audio wiring is sold by people who have > learned to make wire that does not degrade an audio signal. > Such wire is routinely sold by Siltech, Nordost, Audio Revelations, > PranaW .......
216: Tubes Asylum, RE: REVIEW: New Sensor Gold Lion KT88 Re-issue Tubes (0.00)
Posted by LinuxGuru on 2012-12-08, 03:27:34 (83.99.228.190)
I use reissue GL KT88, KT120, 6P3S-E, Shuguang 6550, Shuguang 6L6GC. These GL KT88 from New Sensor are top performers from any standpoint. I have no BIAS drift problems with any of these tubes. Additi .......
217: Tubes Asylum, RE: Recently Produced 12AX7, 6SN7 AND 5AR4 (0.00)
Posted by LinuxGuru on 2012-11-25, 06:47:07 (83.99.228.190)
Hi Music Man Bob, Why bother to look for something, when you can get excellent NOS Russian 6N2P-EV (~12AX7) and 6N8S (=6SN7) for close to nothing? For 6N2P-EV you have to rewire filament, however, but .......
218: Tube DIY Asylum, RE: High Voltage Power Supply - Did you know? (0.00)
Posted by LinuxGuru on 2012-11-22, 09:24:05 (83.99.228.190)
250V is too low voltage for typical B+. There are similar products, like TDK Labmda or Ametek. Some models of Ametek can output up to 800V in range of 670W - 150kW. Since tube amplifiers are relativel .......
219: Tube DIY Asylum, RE: Push-Pull crossover distortion, in general (0.00)
Posted by LinuxGuru on 2012-11-20, 10:40:25 (83.99.228.190)
Hi, gusser, Are you talking about Mullard 5-20 with LTP? What kind of CCS you were using, mosfet or dedicated chip like 10m45s ? Thanks. .......
220: Speaker Asylum, RE: Supravox TG-1: High Efficiency Tweeter (0.00)
Posted by LinuxGuru on 2012-11-16, 14:03:21 (83.99.228.190)
Hi, thetubeguy1954, Thanks for suggestion. Although Supravox TG-1 will fit for sure, its cost 320 Euro ($406)/pc is prohibitive, especially for 4 pcs. Matsushita/Panasonic somehow managed to get all n .......
221: Speaker Asylum, RE: High Efficiency Tweeter Suggestion Please (0.00)
Posted by LinuxGuru on 2012-11-11, 11:25:13 (83.99.228.190)
Hi, djk ! Thanks for suggestion, diysoundgroup is in USA, I'm in Europe. So I'm looking for solution which is available for sale in Europe. Its OK to change original look. If necessary, I can keep sup .......
222: Speaker Asylum, RE: High Efficiency Tweeter Suggestion Please (0.00)
Posted by LinuxGuru on 2012-11-11, 04:12:56 (83.99.228.190)
Diameter of the horn hole is 1.5 cm (0.59 inches). I can cut piece of plastic to make it bigger if necessary. Tweeter is 8 Ohm. BTW, for SB-G910 I will have to make new horns with diffuser anyway. Is .......
223: Speaker Asylum, RE: High Efficiency Tweeter Suggestion Please (0.00)
Posted by LinuxGuru on 2012-11-10, 17:17:59 (83.99.228.190)
Here is how these speakers looks like .......
224: Speaker Asylum, High Efficiency Tweeter Suggestion Please (0.00)
Posted by LinuxGuru on 2012-11-10, 17:16:54 (83.99.228.190)
Hi ! My friend acquired a pair of Technics SB G710 speakers with burned tweeters. Repair is not possible - voice coil burned during heavy overdrive and melted plastic surroundings. I have a pair of .......
225: Tube DIY Asylum, RE: fixed bias for PP KT88 questions (0.00)
Posted by LinuxGuru on 2012-11-02, 14:20:06 (83.99.228.190)
> I got that bias recipie from a long time audiophile Audio design is not a cooking, its guided by laws of physics and math. Any formula please, or test result, e.g. S/N ratio improvement by means of .......
226: Tube DIY Asylum, RE: fixed bias for PP KT88 questions (0.00)
Posted by LinuxGuru on 2012-11-02, 13:16:58 (83.99.228.190)
lovetube, I would suggest you to get a book "Designing Power Supplies for Tube Amplifiers", written by Merlin Blencowe. Very well written, simple, comprehensive, and very professional. For this partic .......
227: Tube DIY Asylum, RE: fixed bias for PP KT88 questions (0.00)
Posted by LinuxGuru on 2012-11-02, 13:06:21 (83.99.228.190)
> Not only should you use a full wave bridge and a choke input, > you should REALLY run the bias supply from a small separate > transformer, solely dedicated to bias supply duty only. Nonsense. BIAS s .......
228: Tube DIY Asylum, RE: PC audio testing: audio interface for windows 7... (0.00)
Posted by LinuxGuru on 2012-11-01, 16:00:36 (83.99.228.190)
> A REAL WORLD EXAMPLE: A friend built an amp and was raving how it > was so detailed he could finally hear differences in RCA interconnect > cables. I was skeptical so we measured it and found out it .......
229: Critic's Corner, RE: Strange review of Rogers amp by Dudley in. Stereophile (0.00)
Posted by LinuxGuru on 2012-10-17, 16:40:21 (83.99.228.190)
> Power transformer buzz is fairly common. Its common for poorly constructed equipment, built from of the shelf el-cheapo parts. I see no reasons why quite expensive gear should not have custom build .......
230: Tube DIY Asylum, RE: Film? (0.00)
Posted by LinuxGuru on 2012-10-14, 13:18:53 (83.99.228.190)
> Me, I agree as I have yet to see a digital image that can > capture all that 35mm film can. But that subtle difference > is far outweighed by the other benefits of digital imaging. Pro digital studi .......
231: Tube DIY Asylum, RE: PC-Based Audio Testing (revisited) (0.00)
Posted by LinuxGuru on 2012-10-14, 04:05:04 (83.99.228.190)
> I don't know about these packages but I was wondering if limiting > to the audio band is the way forward because stuff outside the > audio band can affect pereformance by doing all sorts of crazy th .......
232: Tube DIY Asylum, RE: PC-Based Audio Testing (revisited) (0.00)
Posted by LinuxGuru on 2012-10-13, 16:39:08 (83.99.228.190)
I bought ESI Juli a while ago on eBay, it cost the same as M-Audio, there were no other consideration except immediate availability. You (probably) will want to isolate DUT from PC sound card GND, PC .......
233: Tube DIY Asylum, RE: PC-Based Audio Testing (revisited) (0.00)
Posted by LinuxGuru on 2012-10-13, 14:38:16 (83.99.228.190)
Actual measurement of push-pull amplifier. Amplifier PCB mounted on veneer plate (not within metal box), wires to power supply are over 1m, so there some 50/100Hz hum products, albeit at very low l .......
234: Tube DIY Asylum, RE: PC-Based Audio Testing (revisited) (0.00)
Posted by LinuxGuru on 2012-10-13, 14:28:32 (83.99.228.190)
Follow-up to my previous post: ESI Juli + Pete Millett Sound Card Interface + Arta loopback test, 1.9V output, 96kHz sampling rate. Just look how low THD is. THD+Noise could be better, however. 50H .......
235: Tube DIY Asylum, RE: PC-Based Audio Testing (revisited) (0.00)
Posted by LinuxGuru on 2012-10-13, 14:20:26 (83.99.228.190)
I use ESI Juli and ARTA on Quad Core PC. There have been some problems with drivers latency, but they are solved somehow with updating drivers and disabling on-board audio. Apart from sound card, you .......
236: Tubes Asylum, RE: How much does a good 6sn7 tube cost (0.00)
Posted by LinuxGuru on 2012-10-05, 13:23:16 (83.99.228.190)
Take a Russian NOS 6N8S - excellent tube, sounds great, and costs close to nothing. .......
237: Tubes Asylum, RE: Unfortunately, there's no schematic available (0.00)
Posted by LinuxGuru on 2012-10-01, 05:18:03 (83.99.228.190)
I found MV75 schematic. Possibly (but not sure) MV50 is lower powered version of this one. Yes, in MV75 these are AC balance pots on LTP phase invertor. Please take a look on PCB where these post conn .......
238: Tubes Asylum, RE: Unfortunately, there's no schematic available (0.00)
Posted by LinuxGuru on 2012-10-01, 05:09:38 (83.99.228.190)
Tube amps fall into several typical topologies, CJ is among them. You can re-construct part of schematic these pots belongs to and post here. Its my guess these are AC balance pots, without schematic .......
239: Tubes Asylum, RE: Conrad Johnson MV-50 Power Amp Additional Adjustment Query (0.00)
Posted by LinuxGuru on 2012-10-01, 04:28:29 (83.99.228.190)
Please post schematic and # of these pots (on schematic diagram). We are not magicians to read schematic by photo. Its very likely these are AC balance pots for phase invertors. .......
240: Tube DIY Asylum, RE: power supply chokes (0.00)
Posted by LinuxGuru on 2012-09-26, 15:44:53 (83.99.228.190)
Hard to say without picture or anything. Quite possible these are common mode chokes. You can use them in CLCL but first you need to disassemble a core and re-stuff with air gap 0.5mm or so. ::: TOPIC .......
241: Tube DIY Asylum, RE: The cheapest and probably best answer for" timp" (0.00)
Posted by LinuxGuru on 2012-09-19, 04:58:59 (83.99.228.190)
Better to replace power transformer, that's not very expensive. .......
242: Tube DIY Asylum, RE: Name calling now? (0.00)
Posted by LinuxGuru on 2012-09-16, 09:26:19 (83.99.228.190)
> The fact remains that no credible data exists to support these > crazy audiophile wire ideas. But there are very serious profits made with this odd form of addiction. Its not exactly junk science, .......
243: Tube DIY Asylum, RE: For precision work... (0.00)
Posted by LinuxGuru on 2012-09-16, 03:08:09 (83.99.228.190)
> The inside of a PC is very hostile in terms of RFI. > The power supply rails are also full of noise and small spikes. That's indeed true. But after some work, I've got -108dB noise floor with ESI .......
244: Tube DIY Asylum, RE: 9-Pin Sockets - What's Available? (0.00)
Posted by LinuxGuru on 2012-09-16, 02:00:09 (83.99.228.190)
And the bottom on PCB. .......
245: Tube DIY Asylum, RE: 9-Pin Sockets - What's Available? (0.00)
Posted by LinuxGuru on 2012-09-16, 01:58:45 (83.99.228.190)
Hi, TK, There are NOS Russian PCB mounted sockets, but they are very very scarce. BTW, when I need PCB mounted sockets and didn't had ones, I managed to mount standard sockets on PCB, with some ext .......
246: Tube DIY Asylum, RE: 9-Pin Sockets - What's Available? (0.00)
Posted by LinuxGuru on 2012-09-15, 15:02:41 (83.99.228.190)
You can use PCB mounted sockets and small custom built PCBs as auxiliary terminal point and mounting frame (with metal spacers). .......
247: Tube DIY Asylum, RE: PC based audio analyzers... (0.00)
Posted by LinuxGuru on 2012-09-15, 11:15:35 (83.99.228.190)
The package you mention doesn't seem to be a very good deal. Here is what you need. 1) Desktop PC, not laptop. 2) ESI Juli sound card - can be bought very cheap as second hand. Very low distortions an .......
248: Tube DIY Asylum, RE: To be clear... (0.00)
Posted by LinuxGuru on 2012-09-15, 01:24:02 (83.99.228.190)
> Anyway, once you are talking about people and music, scientific > law is out the window. Sure. Who constructed audio gears? DAC chips, op-amps, MP3 players for example? Cable tweakers or real engine .......
249: Tube DIY Asylum, RE: To be clear... (0.00)
Posted by LinuxGuru on 2012-09-14, 15:40:28 (83.99.228.190)
Hi, Joe, > Seems like a very short list of specs to me. I mean frequency > response isn't even on it! What about phase distortion? 1) Replacing one small piece of wire with another in audio amp will n .......
250: Tube DIY Asylum, RE: To be clear... (0.00)
Posted by LinuxGuru on 2012-09-14, 14:34:19 (83.99.228.190)
> I will state that changing to Less than a foot of AudioNote Lits > wire in a Silbatone amplifier made a distinct improvement over > the Korean stuff we were using previously. OK, then, there must be .......
251: Tube DIY Asylum, RE: Paul, It has strayed (0.00)
Posted by LinuxGuru on 2012-09-13, 11:28:27 (83.99.228.190)
> It's surprising that after some 6 years of heated discussion here, > and nobody has risen to the challenge and brought an amp to RMAF > to run against Dennis's. Its like an anecdote about evasive Jo .......
252: Tube DIY Asylum, RE: Interesting Factoid (0.00)
Posted by LinuxGuru on 2012-09-04, 04:12:02 (83.99.228.190)
> IMO, the best ADC/DAC chips today are the AKM. Hi, gusser, Did you constructed DAC/ADC schematics/PCBs yourself, or used off-the shelf available (if any)? AKM have reference schematic, but there a .......
253: Tube DIY Asylum, RE: Interesting Factoid (0.00)
Posted by LinuxGuru on 2012-09-03, 14:02:46 (83.99.228.190)
Hi, gusser, You mentioned in your posts that you were involved in design/installation of recording studio. Which DAC/ADC chips you were using? Top 32bit like ESS Sabre, AKM4399 or something more commo .......
254: Tubes Asylum, RE: 12BH7: best tube or alternative for Art Audio PX-25 (0.00)
Posted by LinuxGuru on 2012-09-02, 11:25:26 (83.99.228.190)
> Are there any alternative tubes that would be better > harmonically or easier to find? You can also try Russian 6N6P tubes, they are nothing but excellent. You may need to change heater wiring, how .......
255: Tube DIY Asylum, RE: are you for real? (0.00)
Posted by LinuxGuru on 2012-08-31, 04:55:01 (83.99.228.190)
> Dennis lost everything in the fire While this really unhappy accident, I think he got an insurance for everything lost. With prices of real estate falling, he may afford much better house now. As Ru .......
256: Tube DIY Asylum, RE: Truly Low DCR Build (0.00)
Posted by LinuxGuru on 2012-08-23, 13:14:25 (81.240.181.90)
Anyone who is not satisfied with American built low DCR amps there is another prophet to follow, this time from Russia. Please see attached picture of 6W vacuum tube SET amplifier (called Maestro .......
257: Tube DIY Asylum, RE: What's all this "modern" power supply? (0.00)
Posted by LinuxGuru on 2012-08-21, 07:10:20 (83.55.13.69)
> There is no single definition of what "modern" is, In technical terms It means recently developed, innovative. So called low DCR supply (in fact, primitive CLCL topology backdates probably to the .......
258: Tube DIY Asylum, Schematic for Microvoltmeter / add-on for Oscilloscope (0.00)
Posted by LinuxGuru on 2012-08-20, 07:07:41 (83.46.184.24)
Hi ! Anyone can suggest schematic (or may be finished products), which could function as micro-voltmeter (with sensitivity starting from 10-3o uV) or even better, add-on for oscilloscope with frequenc .......
259: Tube DIY Asylum, RE: Please provide specific examples (0.00)
Posted by LinuxGuru on 2012-08-20, 02:04:38 (79.151.146.62)
> Please provide specific examples, It is called Critic's Corner :-) .......
260: Tube DIY Asylum, RE: Toroidal Transformers (0.00)
Posted by LinuxGuru on 2012-08-20, 01:51:31 (79.151.146.62)
> Do you know if anyone is making toroidal transformers for tube audio > applications in packages that won't ruin the cosmetics of the gear? Unfortunately, only Plitron have nice packaging but high pr .......
261: Tube DIY Asylum, RE: Then there needs to be both views. (0.00)
Posted by LinuxGuru on 2012-08-19, 13:45:09 (79.151.146.62)
Gusser, while I have no doubts in your professional experience and knowledge of electronics, you seem to be don't aware of some sales and marketing crap. There is quite large boutique market driven be .......
262: Tube DIY Asylum, RE: "This forum belongs to Stereophile, ..." (0.00)
Posted by LinuxGuru on 2012-08-19, 13:10:51 (79.151.146.62)
>>This forum belongs to Stereophile, > Really? How so? It may not be direct ownership (registrars of these 2 web sites are different), but close relationship is obvious. There are a plenty of other po .......
263: Tube DIY Asylum, RE: Too much disagreement about Kool Aid flavors (0.00)
Posted by LinuxGuru on 2012-08-19, 12:14:02 (79.151.146.62)
> Simply banish Jeff and Dennis to the tweaks and cable forums. Not so simple. This forum belongs to Stereophile, and the market this magazine is devoted to is full of blatant charlatanry which is a g .......
264: Tube DIY Asylum, RE: Misinformation ??? (0.00)
Posted by LinuxGuru on 2012-08-19, 02:16:09 (79.151.146.62)
> ( Q1 ) Will a choke radiate less into the amp if the rectifier feeds > the start of the winding, close to the laminations? .... and conversely I have several large book devoted to power supply cons .......
265: Tube DIY Asylum, RE: Help sought .................................. (0.00)
Posted by LinuxGuru on 2012-08-18, 01:40:16 (79.151.146.62)
IMHO quite simple. You will need RLC-meter (capable of measurement at 10 KHz), and a piece of aluminum foil from your kitchen. Wrap that foil around coil, and measure R at 10 KHz (with one terminal of .......
266: Tube DIY Asylum, RE: Does anyone know what this means? Carverisms. (0.00)
Posted by LinuxGuru on 2012-07-31, 11:07:07 (83.99.228.190)
Hi, Steve ! > The circuit has been around for eons and can be fitted to most PP > output stages without too much trouble. It was discussed in some > detail a few years ago in an issue of Audio Express .......
267: Tube DIY Asylum, RE: Q: UL PP Instability - Anode Grid2 Snubber (0.00)
Posted by LinuxGuru on 2012-07-04, 14:44:41 (83.99.228.190)
Hi, folks ! Thanks a LOT to all who replied with helpful ideas, tips and suggestions! Schematic is slightly modified Williamson (available in a bunch of sources), switchable between penthode, UL, C .......
268: Tube DIY Asylum, Q: UL PP Instability - Anode Grid2 Snubber (0.00)
Posted by LinuxGuru on 2012-07-03, 14:35:40 (83.99.228.190)
Hi, folks, I have stability problems with PP UL amp, 2xKT88, 3.9K transformer, 460V B+. There is a common trick, described in several sources, connecting RC snubber between anode and grid #2 of the .......
269: Tube DIY Asylum, RE: I did this years ago (0.00)
Posted by LinuxGuru on 2012-06-06, 12:15:35 (83.99.228.190)
Hi, Ralph, May you consider to post a schematic of your mod? Did you used DC restorer or standard fixed bias? .......
270: Vintage Asylum, RE: Interesting link, thank you! (0.00)
Posted by LinuxGuru on 2012-05-12, 06:02:11 (83.99.228.190)
> After seeing the pictures, I have to disagree. This mod looks > like a half decent hack job. Large electrolytics secured with > tie wrap? That ain't neat. I see nothing wrong with securing can caps .......
271: Tube DIY Asylum, RE: Strange Stability Enhancement Trick (0.00)
Posted by LinuxGuru on 2012-05-12, 05:03:40 (83.99.228.190)
Thanks to all who replied! I wonder is it possible to use this technique with LTP + PP, as shown on the schematic attached (circled red)? I'm not sure LTP with DC coupling to the output stage (albeit .......
272: Tube DIY Asylum, Strange Stability Enhancement Trick (0.00)
Posted by LinuxGuru on 2012-05-11, 15:40:54 (83.99.228.190)
Hi ! in the article published in Audiocraft by David Hafler, "Modernize your Williamson Amplifier", author introduced strange trick - connecting 1 MOhm resistors parallel to coupling caps leading to o .......
273: Tube DIY Asylum, RE: ethics (0.00)
Posted by LinuxGuru on 2012-05-07, 05:16:24 (83.99.228.190)
> I found the thread pointing out that these are pirated designs, > and "based on" means "filched from". Very little chance to be so. Tube schematics are very typical, a few of good books/magazines p .......
274: Tubes Asylum, RE: With the proliferation of "less expensive" Chinese tube amps . . . (0.00)
Posted by LinuxGuru on 2012-05-02, 13:00:49 (83.99.228.190)
> The market is awash with tons of amps using PCBs. How far > have PCBs come in transparency compared to Point-to-point > construction? Its possible to create both excellent and bad amps with either P .......
275: Tube DIY Asylum, RE: power transformer design questions or call it debate . (0.00)
Posted by LinuxGuru on 2012-04-28, 01:21:14 (83.99.228.190)
> " HIGH FIDELITY" is 20 Ohms or less DCR. > " ULTRA HIGH FIDELITY" is 10 Ohms or less DCR. And what is the meaning of these statements in terms of engineering? Any s/n ratio, dynamic range numbers, .......
276: Tube DIY Asylum, RE: half a mind? (0.00)
Posted by LinuxGuru on 2012-04-05, 09:40:06 (83.99.228.190)
> Basically NO is the answer, except that the supply uses a non > critical L1 and low value C1. Henry Pasternak has recently > posted on this Forum his mock up, measurements, etc. and has > showed us .......
277: Tube DIY Asylum, RE: half a mind? (0.00)
Posted by LinuxGuru on 2012-04-04, 14:56:08 (83.99.228.190)
> Note Dan, John's use of the specific words "final amp" in the > first sentence, so we all clearly know exactly what he is > talking about : > "The final amp using this PS sounds amazing. Supplies bu .......
278: Tube DIY Asylum, RE: Tribute Transformers? (0.00)
Posted by LinuxGuru on 2012-03-14, 01:13:44 (83.99.228.190)
> You will need mucho patience for this iron to become available to you. > I sat for nearly nine months to get the iron to build my 47 amplifier. > That's a lot of idle time, but it paled in compariso .......
279: Tube DIY Asylum, RE: Printed Circuits? (0.00)
Posted by LinuxGuru on 2012-03-07, 15:25:24 (83.99.228.190)
> I have seen quite a few inmates here claim "PC boards sound bad" > of course with the lack of any data to back up such a broad caim. > Yet Tubelab.com did some tests (he's an EE and works on cell > .......
280: Tube DIY Asylum, RE: Toroidal Transformer Question (0.00)
Posted by LinuxGuru on 2012-02-25, 14:45:46 (83.99.228.190)
I use toroids (both power and output, and even fixed air gap filter choke). In short - very happy & satisfied. If its a power transformer, you also need electrostatic shield between primary and second .......
281: Tubes Asylum, RE: Victor, thanks! (0.00)
Posted by LinuxGuru on 2012-02-18, 05:22:18 (83.99.228.190)
"EV" is long-life version of ordinary tube (5000 hrs). Star sign means OTK - quality control compliance (the same you can find on other products like milk and cheese). "Military quality" is more a mar .......
282: Tubes Asylum, RE: Take a look at this. (0.00)
Posted by LinuxGuru on 2012-01-02, 15:19:29 (83.99.228.190)
According to Shuguang, there are Normal (ordinary) and Library (collect) editions of these tubes. Difference in price is quite small when ordering MOQ (minimum order quantity) 100 pairs, and nowhere c .......
283: Tube DIY Asylum, RE: Russian electrolytic capacitors anyone? (0.00)
Posted by LinuxGuru on 2011-12-14, 09:21:19 (83.99.228.190)
Forget about NOS Russian electrolytic caps once and forever. Very poor quality. Take Panasonic or Rubicon instead. .......
284: Tube DIY Asylum, RE: Wow, Neff, I fully AGREE with you..... (0.00)
Posted by LinuxGuru on 2011-12-10, 14:33:16 (83.99.228.190)
> Have fun trying. I already showed you the ultimate B+ supply topology Jeff, can you please post it on the forum? .......
285: Tube DIY Asylum, RE: Ultimate B+ Power Supply (0.00)
Posted by LinuxGuru on 2011-12-09, 00:34:33 (83.99.228.190)
> I believe shunt regulated power supplies will not only have superior > voltage regulation vs non-regulated designs under varying current Shunt regulated power supply is not a good idea for 400 - 60 .......
286: Tube DIY Asylum, RE: Pinging Thomas Mayer... or ?? (0.00)
Posted by LinuxGuru on 2011-12-08, 05:22:06 (83.99.228.190)
I can't comment on sonic properties of the product I have never seen/tested/measured/heard. However. Look at frequency response (graph 3, primary in series connection, single-ended input & secondary p .......
287: Critic's Corner, RE: Amplfier Types - Absolute Sound (0.00)
Posted by LinuxGuru on 2011-11-13, 13:53:23 (83.99.228.190)
Question of taste. Listen to particular units and take whatever you really like. There are many different technologies/ways to achieve excellent result(s). .......
288: Tubes Asylum, RE: Swapped.... (0.00)
Posted by LinuxGuru on 2011-10-31, 01:10:48 (83.99.228.190)
Better if you ship this amp to someone who can fix it. I think original manufacturer can do it. Depends where you are you can find forum members like Jim McShane or Mike Samra who also can help. ::: T .......
289: Tubes Asylum, RE: I have beginner skills and some equipment. (0.00)
Posted by LinuxGuru on 2011-10-30, 14:50:07 (83.99.228.190)
If BIAS circuit failed you risk to overheat output tubes. Try to swap small signal tubes first. Additionally, it would be very helpful if you can get schematics of this amp. .......
290: Tubes Asylum, RE: I have beginner skills and some equipment. (0.00)
Posted by LinuxGuru on 2011-10-30, 13:47:04 (83.99.228.190)
OK, excellent. 1) If its a monoblocks, try to measure current drawn by each of them (with input shortened and 8 Ohm dummy load like 50W wirewound resistor). If power consumption of bad channel conside .......
291: Tubes Asylum, RE: Tragedy Strikes -- Quicksilver Mid-Monos (0.00)
Posted by LinuxGuru on 2011-10-30, 13:25:27 (83.99.228.190)
Do you have any electric skills and equipment? .......
292: Tubes Asylum, RE: Genalex Gold Lion 6922 noisy from the start (0.00)
Posted by LinuxGuru on 2011-10-18, 12:52:24 (83.99.228.190)
Mike, may be hiss you hear is the result of oscillation? Can you verify this with the scope for example? .......
293: Tubes Asylum, RE: KT88 PP anyone built this? (0.00)
Posted by LinuxGuru on 2011-10-18, 12:45:56 (83.99.228.190)
This is pretty ordinary Williamson-like amplifier with cathode feedback, originally constructed by Kenneth Olson in 1955. I have full scan of this article if someone need it (link provided by original .......
294: Tube DIY Asylum, RE: This is exactly what I had in mind... (0.00)
Posted by LinuxGuru on 2011-09-26, 14:51:32 (83.99.228.190)
> that the reason for the consistently low readings (vs expected based > on manufacturer labelling) is due to low current coming from the > typical meter or some issue of that nature. Inductance is no .......
295: Tube DIY Asylum, RE: inductance meters (0.00)
Posted by LinuxGuru on 2011-09-26, 13:57:14 (83.99.228.190)
> I have a Chinese Honeytek A623 inductance meter and it seems to > measure quite accurately on low inductances but a 50H Hammond > reads 26H, manufacturer claims 1,5% accurancy and of course, > does .......
296: Tube DIY Asylum, RE: Try adding up the cost of buying small lots of Iron and Wire... (0.00)
Posted by LinuxGuru on 2011-09-24, 10:31:55 (83.99.228.190)
> "Note: DCR of winding is the result of the design and cannot > be determined prior to building. Requesting a specific > DCR will be ignored." > This is not impossible by the laws of physics. It is j .......
297: Critic's Corner, RE: "Simple people" is code for tea partiers and fans of Fox News. (0.00)
Posted by LinuxGuru on 2011-08-21, 09:28:27 (83.99.228.190)
> We need a national industrial policy, and yes, that includes > tariffs on goods coming from corrupt countries like China > that have virtual slave labor and non-existant environmental > regulations. .......
298: Vintage Asylum, RE: Help with Fisher restoration kits (0.00)
Posted by LinuxGuru on 2011-08-16, 10:52:59 (83.99.228.190)
If you need after-sales technical support, contact Jim McShane. IMHO you should tell him straight about your skills level and experience, hes patience answering e-mails may not be infinite. ::: TOPIC: .......
299: Tubes Asylum, RE: Nearly a megawatt tube amplifier (0.00)
Posted by LinuxGuru on 2011-08-10, 09:57:52 (83.99.228.190)
Although I'm barely use more then 0.5 - 1W from my tube amp, the design and implementation of these amps are really remarkable. Bob Carver used DC restorer, it means VERY low idle current, and very lo .......
300: Vintage Asylum, RE: Marantz 9 reissue (0.00)
Posted by LinuxGuru on 2011-05-16, 13:48:48 (83.99.228.190)
Hi, Joe ! When you get one can you please share your impressions ? .......
301: Critic's Corner, RE: Changes needed in audio reviews (0.00)
Posted by LinuxGuru on 2011-05-06, 13:29:52 (83.99.228.190)
> I am looking for value, whether in wines, clothes, or audio equipment! Then there are 3 ways to go: trusted brands like McIntosh, JBL, Denon, Pioneer; vintage DIY. .......
302: Tube DIY Asylum, RE: amp tweaks (0.00)
Posted by LinuxGuru on 2011-05-06, 09:55:05 (83.99.228.190)
> Just off topic...do you have any books you can recommend > to actually learn and get better understanding of tube > amp/preamp designs ? #1 - Morgan Jones books of course. #2 - whatever you like fro .......
303: Tube DIY Asylum, RE: amp tweaks (0.00)
Posted by LinuxGuru on 2011-05-06, 09:46:31 (83.99.228.190)
> Did you even read his post? > He wants a warmer presentation. > The 6P3S-E is nice but not warmer. I wouldn't agree with this classification of 6P3S-E, because I have PP amp where I have tried 6P3S- .......
304: Tube DIY Asylum, RE: amp tweaks (0.00)
Posted by LinuxGuru on 2011-05-05, 14:30:57 (83.99.228.190)
> I would add a 390K ohm resistor from the grid of the preamp tube > to the bottom of the 390 Ohm cathode resistor. That will ensure > the grid doesn't float when the selector switch is set to "Input. .......
305: Tube DIY Asylum, RE: amp tweaks (0.00)
Posted by LinuxGuru on 2011-05-05, 13:26:37 (83.99.228.190)
I would suggest to replace EL34 with matched quad of NOS Russian tubes 6P3S-E (exactly "6P3S-E", not "6P3S"). You can't by any better tube for these money. Before installing 6P3S-E, use trim pots to s .......
306: Tubes Asylum, RE: Another KT88 Red-Plate (0.00)
Posted by LinuxGuru on 2011-05-02, 04:12:04 (83.99.228.190)
> but the tubes fluctuate down to 30 and up to 65ma - at > least that is the range I’ve seen If ONLY ONE tube is so unstable, it is bad socket, leaky coupling cap, or bad soldering joint on the socket .......
307: Tubes Asylum, RE: I should have known...common sense isn't worth much when... (0.00)
Posted by LinuxGuru on 2011-05-01, 01:57:14 (83.99.228.190)
> LinuxGuru, try list an iPhone on internet for sale and claim it is > new, directly from factory and has Apple factory warranty - as > good as what you can get from any Apple store and make potential .......
308: Tubes Asylum, RE: Again, think about this... (0.00)
Posted by LinuxGuru on 2011-04-30, 15:49:49 (83.99.228.190)
> it's obvious to even the casual observer that *he knows* he > had no right to be selling the Psvane tubes to the general public Please point out to any article in civil or criminal law which could s .......
309: Tubes Asylum, RE: I have read both.................... (0.00)
Posted by LinuxGuru on 2011-04-28, 14:07:21 (83.99.228.190)
> Why don't you recommend people like Clark in China to copy western > products with a different brand - they will be discounted on price, > they will be as good, they are very useful to save money fo .......
310: Tubes Asylum, RE: I have read both.................... (0.00)
Posted by LinuxGuru on 2011-04-28, 11:58:52 (83.99.228.190)
> You appears to be supporting people who smuggle Chinese products to > the west despite of quality yesterday - assuming you were > implying quality was all good then... Smuggling is a crime, a compan .......
311: Tubes Asylum, RE: He said-She said (0.00)
Posted by LinuxGuru on 2011-04-27, 00:01:30 (83.99.228.190)
There are tens of companies in China selling Shuguang Treasure/Psvane vacuum tubes. Since MOQ (minimum order qty) directly from Shuguang factory is 50 - 100 pcs, most of them buying from a couple of l .......
312: Critic's Corner, RE: Changes needed in audio reviews (0.00)
Posted by LinuxGuru on 2011-04-25, 13:17:33 (83.99.228.190)
> I don't get your point. My point is business is business, its all about money. Blind testing? Does it increase profits? Nope. Its not needed, then. Old School (sorry, I don't know your name), audiop .......
313: Critic's Corner, RE: Changes needed in audio reviews (0.00)
Posted by LinuxGuru on 2011-04-25, 12:35:42 (83.99.228.190)
> Exactly WHY Guru? Hi-Fi Critic does it. Stereophile used to do it. > Afraid of exposing "reviewers" as incompetent? Afraid of > offending advertisers? Blind test are not possible with many types of .......
314: Critic's Corner, RE: Changes needed in audio reviews (0.00)
Posted by LinuxGuru on 2011-04-22, 13:03:49 (83.99.228.190)
> (1) Blind tests are needed. In audio evaluation, as in > wine ratings, it's all too easy for the reviewer to be > influenced by price, brand, and type (ss or tube; > digital or analogue). Hundreds o .......
315: Tube DIY Asylum, RE: Progress on my 211s (0.00)
Posted by LinuxGuru on 2011-04-10, 03:10:23 (83.99.228.190)
Great build, especially casework. BTW, how you attach front panel? With small/short screws from the backside? .......
316: Tube DIY Asylum, RE: Panasonic polypropylenes? (0.00)
Posted by LinuxGuru on 2011-04-06, 00:46:20 (83.99.228.190)
I used Panasonic capacitors, both electrolytic and metal film, in several my projects. Excellent caps, nothing else to say. .......
317: Tubes Asylum, RE: Problem With Jim McShane's Web Site (0.00)
Posted by LinuxGuru on 2011-03-27, 13:03:10 (83.99.228.190)
For permanent e-mail gmail (google mail) will be possibly the best choice - you can change hosting provider or domain whenever you want, yet your e-mail address will remain the same. Just set forwardi .......
318: Tubes Asylum, RE: Problem With Jim McShane's Web Site (0.00)
Posted by LinuxGuru on 2011-03-27, 09:38:52 (83.99.228.190)
Hi, Jim! I would suggest you to move to hosting service which provides WordPress support out of the box. It will allow you to publish your pages with word processor like interface. easily setup menus .......
319: Tube DIY Asylum, RE: PP Audio transformers- no feedback needed (0.00)
Posted by LinuxGuru on 2011-03-21, 14:04:04 (83.99.228.190)
There are PP amps with interstage transformer instead of tube-based phase splitter which don't have negative feedback. It is another topology, and have nothing to do with quality of output transformer .......
320: Tube DIY Asylum, RE: Source please (0.00)
Posted by LinuxGuru on 2011-03-02, 09:52:27 (83.99.228.190)
I've purchased them at flea market.They were quite old and dirty. .......
321: Tube DIY Asylum, RE: I need 5.6 ohm 50w resistors. (0.00)
Posted by LinuxGuru on 2011-03-02, 05:22:17 (83.99.228.190)
I use series of 3.3 Ohm 50W wirewound potentiometers as adjustable dummy load. .......
322: Tubes Asylum, RE: I found this comment interesting.............. (0.00)
Posted by LinuxGuru on 2011-01-11, 12:28:01 (83.99.228.190)
> Personally, I think it makes the strongest case for buying NOS > tubes I have ever seen. I have a set of Shuguang (not Treasure) 6L6GC tubes I'm bought for $5/pc year ago from China. Need to say, I' .......
323: Tube DIY Asylum, RE: Modern mil specs were derived from signal testing (0.00)
Posted by LinuxGuru on 2010-12-30, 14:56:11 (83.99.228.190)
> The most conclusive testing was conducted back in the 60's > and 70's when the military was working to improve the targeting > systems of their weapons and improve networking and > communication sys .......
324: Tube DIY Asylum, RE: 6P3S-E Output Power (0.00)
Posted by LinuxGuru on 2010-12-28, 09:35:03 (83.99.228.190)
> I seem to remember several people claiming the 6P3S-E to be > closer to 25W dissipation. Also, many are running them close > to the 450V level that you noted in your post. How far did > you reduce t .......
325: Tube DIY Asylum, RE: 6P3S-E Output Power (0.00)
Posted by LinuxGuru on 2010-12-28, 01:02:19 (83.99.228.190)
For 6P3S-E I had to lower B+ voltage to prevent overheating. 6P3S-E have only 20W anode dissipation rate. .......
326: Tube DIY Asylum, My Latest DIY Draft (Beta) Build - Resurrected Sansui AU-111 (0.00)
Posted by LinuxGuru on 2010-12-27, 15:53:10 (83.99.228.190)
PCB - Bottom .......
327: Tube DIY Asylum, My Latest DIY Draft (Beta) Build - Resurrected Sansui AU-111 (0.00)
Posted by LinuxGuru on 2010-12-27, 15:52:26 (83.99.228.190)
PCB - Top .......
328: Tube DIY Asylum, My Latest DIY Draft (Beta) Build - Resurrected Sansui AU-111 (0.00)
Posted by LinuxGuru on 2010-12-27, 15:51:21 (83.99.228.190)
Hi, tube folks! Finally I've made very nice Christmas and New Year gift for myself - a push-pull amplifier based on legendary Japanese masterpiece of 60th - Sansui AU-111. This is draft (beta) buil .......
329: Tube DIY Asylum, RE: Very interesting (0.00)
Posted by LinuxGuru on 2010-12-27, 09:53:41 (83.99.228.190)
> Steve, you know all this to be true because you have been > the ultimate skeptic. Please continue to be an honest one. > Please don't heap responsibility on others and take none yourself. Simply gre .......
330: Tube DIY Asylum, RE: Rather disingenuous (0.00)
Posted by LinuxGuru on 2010-12-26, 13:12:39 (83.99.228.190)
> What the test shows? > It's what they don't show. They don't show any evidence of > non-linearity beyond the known residual distortion of the > Audio Precision rig. There are many people without any .......
331: Tube DIY Asylum, RE: Transformer potting material (0.00)
Posted by LinuxGuru on 2010-12-26, 09:34:53 (83.99.228.190)
Epoxy or polyester resin. .......
332: Tube DIY Asylum, RE: Evidence of cable nonlinearity (0.00)
Posted by LinuxGuru on 2010-12-26, 08:46:37 (83.99.228.190)
Capacitance of properly made audio cables is very low, something about 50 - 120 pF/m. The distortions caused by this tiny capacitance of 1 - 2m audio cable are not measurable (and no way audible). The .......
333: Tube DIY Asylum, RE: That's exactly what I was thinking. (0.00)
Posted by LinuxGuru on 2010-12-24, 04:12:31 (83.99.228.190)
> I'd much rather do this point to point. It would probably > be much better sounding point to point as well. Properly designed and built point-to-point, tag boards and PCB have no sonic advantages o .......
334: Tubes Asylum, RE: Anybody bought from USSR-Tubes.com? (0.00)
Posted by LinuxGuru on 2010-12-24, 04:06:34 (83.99.228.190)
I can't say anything for this particular company, but IMHO they mistaken "shipped" and "delivered". Mail from Russia usually come in 2 - 3 weeks under normal conditions. Its time for celebration and h .......
335: Tube DIY Asylum, Schematic question - what this cap is for ? (0.00)
Posted by LinuxGuru on 2010-12-21, 15:28:04 (83.99.228.190)
Hi, tube folks, Anyone can tell me what this cap is for - marked with red circle, C91, 0.01 uF, connected between BIAS supply and cathode of 2nd output tube? It doesn't seem to be for high-frequenc .......
336: Tube DIY Asylum, RE: Has anyone used these antec toroidal trans? (0.00)
Posted by LinuxGuru on 2010-12-20, 15:02:47 (83.99.228.190)
> Toroidals are wide band devices, so they generally have the potential > to couple HIGH FREQENCY line hash, much more so than conventional > E-I power transformers. I avoid the problem, by not ever u .......
337: Tube DIY Asylum, RE: 6n1p question..... (0.00)
Posted by LinuxGuru on 2010-12-15, 15:13:21 (83.99.228.190)
Yes, there is 6N1P-EV version. For vendor selection just look for feedback. .......
338: 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 LinuxGuru on 2010-12-12, 11:32:59 (83.99.228.190)
I don't think it have much of usefulness, especially taking into account that interpretation of the result is quite difficult. Except OTL, tube amps are transformer-coupled devices between output stag .......
339: Tubes Asylum, RE: Shuguang Contact info (0.00)
Posted by LinuxGuru on 2010-12-11, 06:38:18 (83.99.228.190)
PM me if you still need one. .......
340: Critic's Corner, RE: Audio Reviewer Factory Tours (0.00)
Posted by LinuxGuru on 2010-12-06, 00:23:59 (83.99.228.190)
Although it is quite interesting to look how products are made, especially if they are good, but the company you mention (Audience Cables) is not a factory, its basically tiny 2-men workshop. I'm work .......
341: Tube DIY Asylum, RE: This may be far fetched but strange things happen.. (0.00)
Posted by LinuxGuru on 2010-12-02, 00:35:48 (83.99.228.190)
Have you called them? Does this company still really exists? .......
342: Tubes Asylum, HK Citation II Output Transformer Data ??? (0.00)
Posted by LinuxGuru on 2010-11-30, 15:24:24 (83.99.228.190)
Hi! Anyone have measured and taken data of Harman-Kardon Citation II amplifier? 1) What is primary impedance - 3.3K, 3.6K, 5K, or whatever else? 2) What is UL tap ratio - 33% or 40%? 3) What is approx .......
343: Tube DIY Asylum, RE: Strange Distortion Problem - Please Help (0.00)
Posted by LinuxGuru on 2010-11-20, 16:17:58 (83.99.228.190)
Thanks a LOT for everyone offered help and advices! Call me whatever, but after long search I found source for this not so obvious problem with distortions on low frequency/high signal level. The most .......
344: Tube DIY Asylum, RE: Strange Distortion Problem - Please Help (0.00)
Posted by LinuxGuru on 2010-11-19, 14:50:39 (83.99.228.190)
> How do you measure each tube's current? Basically there are 2 ways. 1) Amp without power tubes draws 48mA (it uses resistor voltage divider, so don't be surprised). Then, short input, and add tube o .......
345: Tubes Asylum, RE: Please Help (0.00)
Posted by LinuxGuru on 2010-11-19, 13:01:31 (83.99.228.190)
Have you checked idle current of output tubes ? .......
346: Tube DIY Asylum, RE: Strange Distortion Problem - Please Help (0.00)
Posted by LinuxGuru on 2010-11-19, 09:41:07 (83.99.228.190)
> I see your modded schema uses seperate fixed bias pots. > Do you adjust for matching voltages? > If so, unbalanced idle current thru the OPT primary > halves may cause LF distortion. Yes, I use sepa .......
347: Tube DIY Asylum, Modded schematic (0.00)
Posted by LinuxGuru on 2010-11-18, 13:24:04 (83.99.228.190)
Modded schematic .......
348: Tube DIY Asylum, Original Schematic (0.00)
Posted by LinuxGuru on 2010-11-18, 13:22:57 (83.99.228.190)
Original Schematic .......
349: Tube DIY Asylum, Frequency Response (0.00)
Posted by LinuxGuru on 2010-11-18, 13:20:19 (83.99.228.190)
Frequency Response Graph (have to make several posts in row because it is not possible to upload several images at one post). .......
350: Tube DIY Asylum, Strange Distortion Problem - Please Help (0.00)
Posted by LinuxGuru on 2010-11-18, 13:18:11 (83.99.228.190)
Hi, tube folks ! Having run into strange problems I'm now have to call for community help. I have built 40W PP AB1-class 6L6GC amp 485V B+ 5K, original Sansui AU-111 schematic and mod (made by some .......
351: Vintage Asylum, RE: Final price for Fairchild compressor amps. (0.00)
Posted by LinuxGuru on 2010-11-15, 00:05:24 (83.99.228.190)
Someone has schematic of this wonder device ? .......
352: Tubes Asylum, RE: Russian ebay tube seller xryn vindicated? (0.00)
Posted by LinuxGuru on 2010-11-12, 00:35:42 (83.99.228.190)
> These were represented as being tested. > In fact the test results are noted on the bottles. I suspect leakage between filament and cathode can be a cause of this hum, its a factory defect, or resu .......
353: Tubes Asylum, RE: Avoid Russian ebay tube seller xryn (0.00)
Posted by LinuxGuru on 2010-11-11, 14:24:46 (83.99.228.190)
Basically I don't get your warranty claim. You bought very old dump of Soviet era surplus stock, worth $2.5/pc, and trying to claim back your "investment" because of problems which may or may not be r .......
354: Tube DIY Asylum, RE: Qon boost up at low frequnecy of 845PP amplifier (0.00)
Posted by LinuxGuru on 2010-11-10, 00:23:46 (83.99.228.190)
It is not problem at all unless amplifier oscillates. 4V peak compared to 3.7V is +0.68 dB. Second, while you increase output power, low-frequency response will change anyway. .......
355: Tube DIY Asylum, RE: Power supply trouble - help please! (0.00)
Posted by LinuxGuru on 2010-11-09, 14:12:44 (83.99.228.190)
Blown can caps - could it be wrong polarity connections ? .......
356: Tubes Asylum, RE: Whoaaa...pricey... (0.00)
Posted by LinuxGuru on 2010-11-03, 00:06:01 (83.99.228.190)
> The whole Psvane / Treasure thing with regards to 'export' > versions etc stinks Absolutely, according to the Shuguang itself. .......
357: Tube DIY Asylum, RE: Bob Carver says hi (0.00)
Posted by LinuxGuru on 2010-10-29, 04:52:13 (83.99.228.190)
Anyone have actually done this mod to Citation II ? Any feedback appreciated. .......
358: Tube DIY Asylum, RE: The STU Hegeman mod for the Citation 2 (0.00)
Posted by LinuxGuru on 2010-10-29, 04:48:40 (83.99.228.190)
Anyone have actually done this mod to Citation II ? Any feedback appreciated. .......
359: Tubes Asylum, Posted: Vacuum Tube/Valve L1-3/L3-3 Tester User Manual (0.00)
Posted by LinuxGuru on 2010-10-19, 14:01:01 (83.99.228.190)
For anyone who interested - I wrote user manual for this tester (in English), with some translations between Russian/English. Draft version is available here: http://www.vacuum-tube.eu/wp/?p=393 If s .......
360: Tube DIY Asylum, Posted: Vacuum Tube/Valve L1-3/L3-3 Tester User Manual (0.00)
Posted by LinuxGuru on 2010-10-19, 14:00:13 (83.99.228.190)
For anyone who interested - I wrote user manual for this tester (in English), with some translations between Russian/English. Draft version is available here: http://www.vacuum-tube.eu/wp/?p=393 If so .......
361: Vintage Asylum, Looking for 2sb681 + 2sd551 (or analog) (0.00)
Posted by LinuxGuru on 2010-10-19, 09:50:53 (83.99.228.190)
Hi ! I have broken Sansui G8700DB, and now looking for 2sb681 + 2sd551 transistors (originally Toshiba, but any other respectable company like On Semi is also OK). I seen them on sale on eBay, and the .......
362: Tubes Asylum, RE: This is where I buy from and he is very good and sells cheap. (0.00)
Posted by LinuxGuru on 2010-10-17, 02:26:26 (83.99.228.190)
> Do you know how well this dealer matches his tubes? > Or does he just rely on Shuguang's matching process? As long as they matched by both transconductance and plate current everything will be fine .......
363: Tubes Asylum, RE: A Question (0.00)
Posted by LinuxGuru on 2010-10-16, 04:11:37 (83.99.228.190)
> Some of the tubes - at least the 6SN7 sub - come in two "grades", > or at least that is what some other dealers advertise. > ... some fraction of the production can still test better than others. Fo .......
364: Vintage Asylum, RE: Older speakers vs. New speaker technology (0.00)
Posted by LinuxGuru on 2010-10-14, 05:21:57 (83.99.228.190)
This question is too general, and can't be answered without pointing out to price segment, engineering objectives, constructional details, etc. How, for example one can compare modern 5+1 system with .......
365: Tubes Asylum, RE: GEC KT-66 grey glass vs new issue GL KT-66 (0.00)
Posted by LinuxGuru on 2010-10-12, 15:02:40 (83.99.228.190)
K40Y-9 are very big and occupy a lot of space, it is not likely you van mount them on PCB instead of today metal film caps. Better to check with your technician first, or at least, post a photo of you .......
366: Tubes Asylum, Question About High-Fidelity Magazine 195x - 196x (0.00)
Posted by LinuxGuru on 2010-10-03, 12:12:43 (83.99.228.190)
Hi, tube folks! Anyone have seen back issues (195x - 196x) of High-Fidelity Magazine? What kind of material was published these years - mostly reviews of industrial equipment or articles with DIY sche .......
367: Tube DIY Asylum, RE: Help building an ST-70 (0.00)
Posted by LinuxGuru on 2010-09-18, 07:31:10 (83.99.228.190)
Hi, Matthew, Although I'm not in NYC, Columbia, or even in USA, anyone willing to help you would ask the same: What is your background in electronics? What is your experience with soldering iron? What .......
368: Tubes Asylum, Collection of 300 pcs of tube gears on sale on AudioGoON (0.00)
Posted by LinuxGuru on 2010-09-15, 15:24:55 (83.99.228.190)
Hi, folks, Just have a look at this guy. He has a collection of 300 pcs of tube gears and now selling all that stuff (lot linked below is for Sansui only). Its a pity I'm not living in USA :-( http:// .......
369: Tubes Asylum, RE: Speaking of Shuggie Treasures, (0.00)
Posted by LinuxGuru on 2010-09-15, 15:09:23 (83.99.228.190)
Mike, did you got already any Treasures on your bench table ? .......
370: Tubes Asylum, RE: EL 84 on Ebay for Leben (0.00)
Posted by LinuxGuru on 2010-09-15, 13:28:06 (83.99.228.190)
Take 6P14P-EV, Russian NOS military grade - extended lifetime tubes. It is not likely you can find any other so good tube for so affordable price. .......
371: Tube DIY Asylum, RE: "Insane" filter capacitance (0.00)
Posted by LinuxGuru on 2010-09-11, 09:15:58 (83.99.228.190)
Tube amps usually draw relatively low current, 250...400 mA in average, so increasing filter cap capacitance over several hundreds uF lead basically to no meaningful benefit. Very large filter capacit .......
372: Tube DIY Asylum, RE: Volume Control with Loudness and no Taps (0.00)
Posted by LinuxGuru on 2010-09-05, 09:26:42 (83.99.228.190)
Seems like passive circuit is not the best solution. May be someone can suggest active one with 12AX7 or6N1P for example (I have them anyway already)? .......
373: Tube DIY Asylum, RE: Volume Control with Loudness and no Taps (0.00)
Posted by LinuxGuru on 2010-09-04, 15:21:08 (83.99.228.190)
In which book you have schematic with 4-gang pot? May be there is also schematic for conventional pot without tap(s)? .......
374: Tubes Asylum, RE: Shuguang Pavane 845T (0.00)
Posted by LinuxGuru on 2010-09-04, 05:56:09 (83.99.228.190)
I don't like idea to slam any product just because of antipathy to the country of origin, brand, or particular seller. Especially if these tubes are not tested by many people and by those who bash the .......
375: Tube DIY Asylum, Volume Control with Loudness and no Taps (0.00)
Posted by LinuxGuru on 2010-09-03, 15:10:33 (83.99.228.190)
Hi! Anyone have schematic for passive volume control with loudness compensation and 250-500K potentiometer without taps? Tapped pots are very problematic to obtain today unless ordered in quantity .......
376: Tubes Asylum, RE: Jim Mcshane You Obviously Have A Computer Problem (0.00)
Posted by LinuxGuru on 2010-09-03, 05:25:52 (83.99.228.190)
It is not a problem of Jim's computer unless he has wrong/mistyped e-mail address in "reply-to" field. Other possible causes are: 1) Your e-mail program have a bug, wrong setup and inserts bogus addr .......
377: Tubes Asylum, RE: Stay away from KT88Z's on eBay! (0.00)
Posted by LinuxGuru on 2010-08-29, 16:19:37 (83.99.228.190)
Not only obscure ebay sellers deny existence of A/B grade Shuguang Treasures, but also European distributors and Chinese wholesale suppliers of electronic components who carry many items along Shuguan .......
378: Tubes Asylum, RE: Quad II, upsidedown? (0.00)
Posted by LinuxGuru on 2010-08-27, 00:02:17 (83.99.228.190)
Tubes themselves will work well, but your amp's chassis (and all parts inside) may suffer from overheating because stream of very hot air will go up. .......
379: Tube DIY Asylum, RE: This is whats going to save Michigan's economy if (0.00)
Posted by LinuxGuru on 2010-08-21, 03:21:56 (83.99.228.190)
> The US Gov't has not protected our industrial manufacturing base > like most other countries. In fact, we allow inexpensive > imports, yet other countries place a large import tax on our products. > .......
380: Tube DIY Asylum, RE: Current vs. Watts in regards to power amplifiers (0.00)
Posted by LinuxGuru on 2010-08-20, 10:53:36 (83.99.228.190)
> I have seen some people post that although a 2A3 or 300B > can play these loudly enough because of its sensitivity, Yes, you need high-sensitivity speakers for low-power amps. Speakers with sensitiv .......
381: Tube DIY Asylum, RE: It "works" but is COMPLETELY hopeless to read. (0.00)
Posted by LinuxGuru on 2010-08-17, 23:59:25 (83.99.228.190)
Yes, this is the one you send me :-) .......
382: Tube DIY Asylum, RE: Bob Carver says hi (0.00)
Posted by LinuxGuru on 2010-08-17, 12:00:43 (83.99.228.190)
Another question about Citation II. Anyone have tried (or can just suggest), if 12BY7 can be replaced with any Russian-made sharp cut-off penthode without sacrificing sonics? Unfortunately , there are .......
383: Tube DIY Asylum, RE: It "works" but is COMPLETELY hopeless to read. (0.00)
Posted by LinuxGuru on 2010-08-17, 10:45:20 (83.99.228.190)
Due to limitations of AA forum software it is impossible to post several hi-res images. Anyone who interested can download schematic of HK Citation II mods from my web site. I've got these images from .......
384: Tube DIY Asylum, RE: The STU Hegeman mod for the Citation 2 (0.00)
Posted by LinuxGuru on 2010-08-17, 10:41:35 (83.99.228.190)
I've got hi-resolution schematic from Mike (thanks, Mike !). Due to limitations of AA forum software its seems to impossible to post hi-res images. Anyway, anyone interested can download it from my we .......
385: Tube DIY Asylum, RE: It "works" but is COMPLETELY hopeless to read. (0.00)
Posted by LinuxGuru on 2010-08-17, 08:57:32 (83.99.228.190)
Hi, Allen, I have hi-resolution schematic of this mod, please e-mail me if you want a copy. .......
386: Tubes Asylum, RE: MICROPHONICS (0.00)
Posted by LinuxGuru on 2010-08-17, 05:00:53 (83.99.228.190)
> "Many" years is relative. I don't recall hearing the term > in any of the older literature ie Absolute Sound, IAR etc, > at least not commonly. The term has become unfortunately > popular within the .......
387: Tube DIY Asylum, RE: Bob Carver says hi (0.00)
Posted by LinuxGuru on 2010-08-17, 00:27:55 (83.99.228.190)
Hi, Bob! Thanks for clarification. BTW, what are copyright terms of your mods? Do you consider them as public domain, open hardware license (anyone is free to use for whatever purpose but all derivati .......
388: Tube DIY Asylum, RE: The STU Hegeman mod for the Citation 2 (0.00)
Posted by LinuxGuru on 2010-08-12, 23:50:46 (83.99.228.190)
Hi, Mike ! Thanks for mods, but drawing is missing somehow .......
389: Tube DIY Asylum, RE: 6-8 watts from 2a3's? (0.00)
Posted by LinuxGuru on 2010-08-08, 12:12:31 (83.99.228.190)
IMHO replacing speakers is the best option in your case. After all these AN speakers you have hold no magic but Fostex (or something similar) inside. Upon your taste,music and room Klipsch horns, or v .......
390: Tube DIY Asylum, RE: Citation one preamp mod for moving coil cartridges. (0.00)
Posted by LinuxGuru on 2010-08-02, 00:23:57 (83.99.214.85)
Mike, would you please re-post schematic. Link does not work anymore. .......
391: Tube DIY Asylum, RE: ShuGuang 50years TREASURES (0.00)
Posted by LinuxGuru on 2010-07-16, 15:18:33 (83.99.214.85)
There is a seller of these tubes in France. PM me I will e-mail hes contacts. .......
392: Tube DIY Asylum, RE: Audiophiler MKP Cap from Antique Electronics Supply? (0.00)
Posted by LinuxGuru on 2010-07-09, 14:42:30 (83.99.214.85)
I once come across Chinese factory which manufactures these caps when was looking for something else. These are absolutely standard general-purpose axial metal-propylene or metal-polystyrene caps, man .......
393: Tube DIY Asylum, Measuring Leakage Inductance & Stray Capacitance (0.00)
Posted by LinuxGuru on 2010-07-01, 14:08:23 (83.99.214.85)
I took RLC meter from my friend, and made several measurements listed below: Primary resistance - 136 Ohm Secondary Resistance Primary inductance: 100 Hz 1V - 102 H 100 Hz 50mV - 77 H 1 KHz - out of .......
394: Tube DIY Asylum, RE: PP Output Transformer Testing Puzzle (0.00)
Posted by LinuxGuru on 2010-06-30, 00:21:34 (83.99.214.85)
> In order to properly test this transformer you need a > balanced drive signal Hi, Dave! Do you have a ss-based schematic with bandwidth 10Hz - 100KHz (or even better, 200 - 250 KHz)? .......
395: Tube DIY Asylum, RE: This transformer has been nawing at me. (0.00)
Posted by LinuxGuru on 2010-06-29, 11:19:25 (83.99.214.85)
> What did you did you that was different in this design? I did not used any compensation circuit. Construction details of audio output transformers are pretty standard and obvious, apart may be of so .......
396: Tube DIY Asylum, RE: But why go to all this hassle? (0.00)
Posted by LinuxGuru on 2010-06-28, 14:51:29 (83.99.214.85)
> When very high quality transformers are available off > the shelf from a wide range of manufacturers. At first, it was really interesting challenge. Second, the 4 transformers I'm was looking for we .......
397: Tube DIY Asylum, RE: You haven't answered my question. (0.00)
Posted by LinuxGuru on 2010-06-27, 10:54:57 (83.99.214.85)
Hi, Michael, I'll try to answer you question step by step. 1) Micro-gapped is not the same as iron powder distributed gap core. Micro-gap is just very small air gap between two "C" halves of core. You .......
398: Tube DIY Asylum, RE: You haven't answered my question. (0.00)
Posted by LinuxGuru on 2010-06-27, 08:31:16 (83.99.214.85)
> You haven't answered my question I understood your question "how to design PP transformer which can handle several mA of DC current flowing through the primary caused by output stage idle current im .......
399: Tube DIY Asylum, RE: With a toroid, how are you going... (0.00)
Posted by LinuxGuru on 2010-06-27, 05:33:33 (83.99.214.85)
> With a toroid, how are you going to balance > the DC offset in the output tubes? > IMO, this is VITAL. It is absolutely vital for any PP transformer. Lundahl, for example, uses micro-gapped core to .......
400: Tube DIY Asylum, RE: ))is the -4 dB black hole at 40 KHz and "fast" peak... (0.00)
Posted by LinuxGuru on 2010-06-27, 03:52:32 (83.99.214.85)
> It's a resonance created by the capacitances in the trafo > and most likely the leakage inductance. Thanks, Allen! Several fellows suggested the same. I would prefer this roll-off and peak will b .......
401: Tube DIY Asylum, RE: PP Output Transformer Testing Puzzle (0.00)
Posted by LinuxGuru on 2010-06-27, 02:20:51 (83.99.214.85)
> the one db down seems a bit much at 20khz and Im sure > it probably specs much better than that. Mike, generator I used have 4 discrete rotary switches for setup of output frequency. Yes, I noticed, .......
402: Tube DIY Asylum, RE: try a low impedance SS amp (0.00)
Posted by LinuxGuru on 2010-06-27, 02:13:30 (83.99.214.85)
Actually the first test I did (not published here) I used another generator with bandwidth 10Hz - 250 KHz, but with only 6V max output (connected to primary). I loaded secondary with 100 Ohm resistor .......
403: Tube DIY Asylum, RE: PP Output Transformer Testing Puzzle (0.00)
Posted by LinuxGuru on 2010-06-26, 12:48:32 (83.99.214.85)
The whole chart is just 5dB (!) scale, not 50, so roll-off is only big on picture,actually from 12 to 20 KHz is ONLY -1 dB. It do not bothers me, its within norm. What really I don't like is the -4 dB .......
404: Tube DIY Asylum, RE: Any Russian analog of 12BY7 ? (0.00)
Posted by LinuxGuru on 2010-06-26, 12:42:23 (83.99.214.85)
7733 is a Russian tube? Mike, are you sure? .......
405: Tube DIY Asylum, Any Russian analog of 12BY7 ? (0.00)
Posted by LinuxGuru on 2010-06-26, 11:28:18 (83.99.214.85)
Hi! Anyone knows if there is a Russian analog or close substitute of 12BY7 ? Searched through several tube data books, found literally nothing. Thanks in advance ! .......
406: Tube DIY Asylum, PP Output Transformer Testing Puzzle (0.00)
Posted by LinuxGuru on 2010-06-26, 08:53:38 (83.99.214.85)
Hi, folks, Recently I've got 70W PP output transformer, designed by myself, and decided to put it in bench test. I have not finished prototype amp yet, so its impossible to test trafo in real circu .......
407: Tubes Asylum, RE: 6c33c Tube Tester (0.00)
Posted by LinuxGuru on 2010-05-27, 10:09:46 (83.99.214.85)
Russian L1-3 or L3-3 can test these tubes if you build an adapter with high-current filament supply. .......
408: Tubes Asylum, RE: Damaged 845 ... dangerous? (0.00)
Posted by LinuxGuru on 2010-05-23, 02:13:22 (83.99.214.85)
Tube with broken pieces of metal internal parts cannot be safe and vice versa, especially power tube with 1000+ V anode voltage. It may cause electric short of anything and anytime. If it did not happ .......
409: Tube DIY Asylum, RE: how do you figure 200V ? (0.00)
Posted by LinuxGuru on 2010-05-22, 02:15:21 (83.99.214.85)
> Resistors aren't rated for voltage, they are rated for power. Unfortunately, they are (for 1 Ohm resistor it does not make any sense, but for 1M is). Check "maximum permissible voltage" at manufact .......
410: Tube DIY Asylum, RE: Tube novice needs advice on reputable sellers (0.00)
Posted by LinuxGuru on 2010-05-20, 14:55:09 (83.99.214.85)
One more thing for tube buyers ... I've got a transconductance tube tester L3-3 and have to say it is invaluable. Apart for worn-out cathode (and low emission) tubes may suffer from leak between filam .......
411: Tube DIY Asylum, RE: Tube novice needs advice on reputable sellers (0.00)
Posted by LinuxGuru on 2010-05-20, 11:09:25 (83.99.214.85)
Ask Jim McShane, he is really reputable and honest seller with deep knowledge of subject.. http://pages.prodigy.net/jimmcshane/ .......
412: Tubes Asylum, RE: Shuguang Treassure Series KT88-Z vs. NOS Gold Lion KT88 (0.00)
Posted by LinuxGuru on 2010-05-16, 01:58:54 (83.99.214.85)
> Any idea the diff b/n Grade A and B and is there any way > to identify each? I have contacted with 2 Shuguang distributors, both confirmed grade A and B are marketing fakes. The only option one dist .......
413: SET Asylum, RE: I am not pointing at any mfrs or model, and I wasn't criticising the post (0.00)
Posted by LinuxGuru on 2010-05-08, 02:36:57 (83.99.214.85)
> What I don't understand, is why do people make things into a > struggle? Why do that? As joked one Russian artist, "we continuously make heroic struggle against problems we created ourselves". IMHO .......
414: SET Asylum, RE: Decware's claim- EL84 vs. 2A3-- Any comments? (0.00)
Posted by LinuxGuru on 2010-04-19, 12:27:37 (83.99.214.85)
> You know, there are plenty of us who can hear the > difference in every one of these parts Any real proof by means of blind testing? > just the capacitors in a good S.E. monoblock > SHOULD exceed ab .......
415: Tubes Asylum, RE: Luxman CL32 tube help (0.00)
Posted by LinuxGuru on 2010-04-18, 13:53:01 (83.99.214.85)
Please post a schematic or service manual, without reading it it will be a guess only. Most probably 2 - 3 tubes phono pre-amp, 1 tube cathode follower for output, the rest - pre-amp section. ::: TOPI .......
416: SET Asylum, RE: Vintage speakers for a low cost SET system? (0.00)
Posted by LinuxGuru on 2010-04-12, 15:24:55 (83.99.214.85)
I would recommend Technics 4-way speakers of SB-G7xx or SB-G9xx series, with 98 db/W/m efficiency. One of the best speakers I have ever heard, greatly underrated. If you can spare more, consider Techn .......
417: Tubes Asylum, RE: Since the KT88 is being discussed so much (0.00)
Posted by LinuxGuru on 2010-04-01, 11:56:17 (83.99.214.85)
I would like hijack the thread and add Shuguang Treasure KT88 black battle tubes for comparison. .......
418: Tube DIY Asylum, RE: Do (Why do) tube amps have problems driving "difficult" loads? (0.00)
Posted by LinuxGuru on 2010-03-31, 11:22:24 (83.99.214.85)
Output transformer CAN be designed to drive 1 Ohm load, but does it make any sense? IMHO it would be much better to buy good speakers and dump poorly designed boxes on fleabuy.com . .......
419: Tube DIY Asylum, RE: regulated power supply (0.00)
Posted by LinuxGuru on 2010-03-31, 04:53:35 (83.99.214.85)
Pre-amp draws very little current, which BTW is constant. You win basically nothing by means of increasing filter cap capacitance. The schematic you attached is a standard tube regulator described in .......
420: Critic's Corner, RE: Audio gear is always more important than cars, - IMO (0.00)
Posted by LinuxGuru on 2010-03-29, 09:11:03 (83.99.214.85)
> $300K power amps. $65K cd players. $250K speakers. WTF > I never saw those kinds of prices in the 80s or 90s. > And inflation does not count for it. There are some home amps for $600k (e.g. UltraSou .......
421: Critic's Corner, RE: Plea for a new magazine (0.00)
Posted by LinuxGuru on 2010-03-27, 09:26:14 (83.99.214.85)
Yes, AudioXPress is a nice and useful magazine. I know several similar publications but they are all Russian. > They also love to disparage the "high end" Because most of them have engineering backgro .......
422: Critic's Corner, RE: Plea for a new magazine (0.00)
Posted by LinuxGuru on 2010-03-27, 02:51:46 (83.99.214.85)
I suggest you to start web magazine (e-zine), and call for volunteer writers. You can share revenues (if any) from advertising and classified ads with other contributors based for example on the numbe .......
423: Tube DIY Asylum, RE: Source for Russian K40Y-9 PIO caps (0.00)
Posted by LinuxGuru on 2010-03-20, 12:34:47 (83.99.214.85)
Michael, what are you doing with several thousands of these caps? Is this some kind of exotic diet ? .......
424: Computer Audio Asylum, RE: Question for Linux users (0.00)
Posted by LinuxGuru on 2010-03-18, 11:32:34 (83.99.214.85)
Hi, Jon L, 1) You can install OpenOffice, which have applications similar to the ones in MS Office, but you may find (or may be not, depends upon luck) some compatibility issues. Complex VB macros mos .......
425: Tube DIY Asylum, RE: Audio testing software ??? (0.00)
Posted by LinuxGuru on 2010-03-14, 15:21:03 (83.99.214.85)
Arta or RMAA, 1st do not print if you do not pay shareware fees, otherwise fully functional You can see few tests here: http://www.vacuum-tube.eu/audio_pioneer_sm83_tests_en.html .......
426: Tube DIY Asylum, RE: tube circuit design: is there anything new? (0.00)
Posted by LinuxGuru on 2010-03-09, 00:36:27 (83.99.214.85)
In order to design radically new tube amplifier one need radically new-design vacuum tubes.So far there are none since 60th. .......
427: Critic's Corner, RE: Does Stereophile consider it a good thing when Audio company moves production to China? (0.00)
Posted by LinuxGuru on 2010-02-28, 14:05:10 (83.99.214.85)
> how this is a good thing for anyone but the Chinese Its also good for company shareholders/owners since they can get extra profit from the same volume of sales. After all, its THESE people who made .......
428: Critic's Corner, RE: We dont care (0.00)
Posted by LinuxGuru on 2010-02-28, 13:49:48 (83.99.214.85)
> We don't care whether there is child labor in China Do you really think it is so horrible??? My own life experience is just the opposite. I've got my first paid job in 80th (during summer school hol .......
429: Tubes Asylum, RE: More 6PS3-E Test Results (0.00)
Posted by LinuxGuru on 2010-02-27, 02:27:10 (83.99.214.85)
Hi, Jim! At what anode voltage arcing/flashing occured during your tests? .......
430: Tube DIY Asylum, RE: What are my choices? (0.00)
Posted by LinuxGuru on 2010-02-23, 00:12:56 (83.99.214.85)
Sorry, I'm was thinking you are going to build SET and asking for speakers :-))))) Subject of your post did not mention transformers :-)) .......
431: Tube DIY Asylum, RE: What are my choices? (0.00)
Posted by LinuxGuru on 2010-02-22, 13:25:55 (83.99.214.85)
Vintage 4-way Technics, Sansui or Kenwood, whichever you like more. Their sensitivity is about 96 - 98 dB/W/m. Personally, I prefer Technics SB-Gxxx - "holographic" reproduction, excellent bass. Total .......
432: Computer Audio Asylum, RE: Switch to Which Mac? (0.00)
Posted by LinuxGuru on 2010-02-15, 13:33:49 (83.99.214.85)
IMHO iMac probably, but it does not matter much. You can use external semi-professional 192KHz FW or USB DAC if you wish. .......
433: Critic's Corner, RE: Common practices? (0.00)
Posted by LinuxGuru on 2010-02-11, 00:20:37 (83.99.214.85)
I know Chinese OEM factories assembling various types of Audio equipment, and wholesale prices for radio components, so how much it costs is not a secret. If you look at other posts on this thread, yo .......
434: Critic's Corner, RE: Are the "Linn Audio" speaker ads going to keep running in "Stereophile"? (0.00)
Posted by LinuxGuru on 2010-02-10, 12:15:44 (83.99.214.85)
Cannot say anything about the company - never seen products and never heard their speakers. Probably they save some money on not so good interior photography (in UK its very expensive). Anyway, packin .......
435: Tubes Asylum, National Electronic Tube Question (0.00)
Posted by LinuxGuru on 2010-02-06, 12:51:34 (83.99.214.85)
Hi! I saw a surplus shop selling 6080 National Electronic tubes, claiming they are USA made. Picture is not clear, taken probably with camera-phone I cannot see anything meaningful except shape. Is an .......
436: Shady Lane, RE: Andy HiFi--scam alert (0.00)
Posted by LinuxGuru on 2010-02-05, 11:47:58 (83.99.214.85)
An employee from McIntosh Laboratories warned me - it is fraudulent/scam site. > Andy Hi Fi is a rip off artist who advertises > gear at 10% of retail and keeps the money. > Please stay away from him. .......
437: Tubes Asylum, RE: "6N3C-E" - Any time I see that I cringe (0.00)
Posted by LinuxGuru on 2010-02-04, 10:40:22 (83.99.214.85)
Nope, only 20W plate dissipation. Its a drop-in replacement of 6L6 (and that is clearly stated in Russian tube catalog). You can use them instead of 6550/KT66 under certain circumstances but output po .......
438: Tubes Asylum, RE: B+ cap alternatives (0.00)
Posted by LinuxGuru on 2010-02-03, 10:10:18 (83.99.214.85)
I use Panasonic, Nichicon and Rubicon caps.No problems whatsoever. I have 50uF 400V film caps, but they are VERY large. Too large in fact. .......
439: General Asylum, RE: Seeking advice on possible Ebay scam (0.00)
Posted by LinuxGuru on 2009-12-28, 09:17:10 (83.99.214.85)
80% looks like its a PayPal forgery scam. Accept nothing else BUT direct bank transfer, IMHO your chances to get real money are close to zero. BTW, why you have not put limits on auction - no zero fee .......
440: Tube DIY Asylum, RE: Never ending "Last NOS Pair" (0.00)
Posted by LinuxGuru on 2009-12-25, 03:31:01 (83.99.214.85)
May be its a marketing, may be this guy really has only 1 pair of each model, so obviously, its always "last". BTW, I'm not keen about vintage transformers, today quality of ferromagnetic materials is .......
441: Tubes Asylum, Shuguang 6L6GCR and 6550 - Your Experience Please (0.00)
Posted by LinuxGuru on 2009-12-24, 05:34:29 (83.99.214.85)
Hi, tube folks! Based on your experience, how would you rate Shuguang 6L6GCR and 6550, in terms of sonic performance, reliability, and life time? Are they really comparable to EH, SED, WingedC or Russ .......
442: Critic's Corner, RE: Linux and PC Audio (0.00)
Posted by LinuxGuru on 2009-12-21, 12:59:23 (83.99.214.85)
As the Linux specialist, I can state that it does make a sense to use Linux in set-up boxes and digital appliances because of small footprint, speed, low latency, and no-royalty factor. However, beyo .......
443: Critic's Corner, RE: New Stereophile Ad (0.00)
Posted by LinuxGuru on 2009-12-17, 11:47:35 (83.99.214.85)
> Does anybody from Stereophile get any perks from the > manufacturers? Perks would be gifts, dinners, > entertainment, travel or discounts on gear. In other words, you wish to ask anyone of Stereophi .......
444: Critic's Corner, RE: agreed (0.00)
Posted by LinuxGuru on 2009-12-16, 04:59:30 (83.99.214.85)
> ok, build that 30-40 transistor device yourself then > or have you already? Did it over 20 years ago, took Sony schematic for DIY tape cassette deck and excellent schematic for power amp from radio .......
445: Critic's Corner, RE: agreed (0.00)
Posted by LinuxGuru on 2009-12-15, 12:52:54 (83.99.214.85)
> If you're buying $38k speakers your amp should be at > least 1/2 that or equal to the price of the speakers, A 30-40 transistor device for $20K? What exactly so valuable is inside of this $20k box f .......
446: Tubes Asylum, RE: Power Tube Reliability (Long) (0.00)
Posted by LinuxGuru on 2009-12-14, 13:00:21 (83.99.214.85)
The financial loss because of warranty replacement of failed tubes is surely smaller then throughput testing of so huge amount of stock. If the customer cannot understand that sometimes the whole seri .......
447: Tube DIY Asylum, RE: C-core supplier? (0.00)
Posted by LinuxGuru on 2009-12-13, 15:12:42 (83.99.214.85)
Hell overpriced for so cheap material, for that amount you can get custom-build transformers from factory .......
448: Tubes Asylum, RE: Russian Tubes on Ebay (0.00)
Posted by LinuxGuru on 2009-12-08, 09:43:19 (83.99.214.85)
You cannot directly replace KT88 with 6P3S-E, the 2nd is an equivalent of 6L6 with only 20W anode dissipation rate. At least, you must re-bias amplifier and set idle current accordingly. .......
449: Tubes Asylum, RE: Cayin TA-30 Transformer - HELP! (0.00)
Posted by LinuxGuru on 2009-12-07, 13:57:43 (83.99.214.85)
Which transformer blew? Power or audio? Power transformer is not a problem, I had the same in my vacuum tube Pioneer SM-83, and replaced failed EI core with much better custom-build R-core. ::: TOPIC: .......
450: Tubes Asylum, RE: The Problem With Asking Too Many Questions (0.00)
Posted by LinuxGuru on 2009-12-06, 03:55:55 (83.99.214.85)
You can get very informative response and a cap of coffee when you buying heavy machinery equipment like printing presses, which cost starts from $500,000. Although I do not sell tubes, and not going .......
451: Tube DIY Asylum, RE: How big is a complete schematic? (0.00)
Posted by LinuxGuru on 2009-12-04, 14:54:02 (83.99.214.85)
May I ask what software do you use to simulate tube circuits? .......
452: Tubes Asylum, Question - Output Trafo with CFB (0.00)
Posted by LinuxGuru on 2009-11-30, 15:30:45 (83.99.214.85)
Hi, tube folks, There are some output trafos with CFB (cathode feedback). CFB is described as 8% - 15% of primary. Question: does this means 8% - 15% of a) primary inductance b) primary impedance c) p .......
453: Tube DIY Asylum, RE: K40y caps cuts high and low frequencies?? (0.00)
Posted by LinuxGuru on 2009-11-29, 04:00:28 (83.99.214.85)
Did you take frequency response curve from the amp? If not, there are no measurement to support this claim. Drop of frequencies measured in dB, not listening impression. .......
454: SET Asylum, RE: Looking for ideas for a new SET amp. (around $1000.00) (0.00)
Posted by LinuxGuru on 2009-11-28, 13:33:18 (83.99.214.85)
Crackling sound may be a noise from switching power supply if you use digital source like PC sound card. Try to connect this amp to pure analog source (e.g. tape or LP recorder) or to battery-powered .......
455: Tubes Asylum, RE: Chinese tubes on Ebay (0.00)
Posted by LinuxGuru on 2009-11-26, 12:29:33 (83.99.214.85)
A/B quality rating claims are marketing BS. If this would be true, how exactly it happens on factory? And how factory management themselves & QA department defines it? Based on emission test of each t .......
456: Tubes Asylum, RE: Quad II (0.00)
Posted by LinuxGuru on 2009-11-24, 10:38:23 (83.99.214.85)
IMHO $6,000 is insane price for restoration unless original steel chassis is replaced with pure golden one.There are thorny restoration cases, like vintage tube Pioneers SM-8xx series for example, but .......
457: OTL Asylum, RE: Getting down to CCS basics & SPICE implications (0.00)
Posted by LinuxGuru on 2009-11-10, 04:30:53 (83.99.214.85)
Are you going to use TubeCAD or LTSpice? .......
458: Tubes Asylum, RE: The Most Powerful Tube Amplifier Ever Built (0.00)
Posted by LinuxGuru on 2009-11-02, 12:35:40 (83.99.214.85)
I have seen in Russian radio magazine 1200W tube amplifier with GU81M output stage and 3.5kV B+ voltage. Output transformer size is 26x36 sm. Fillament current for each GU81M is 11.5A. A real MONSTER .......
459: Critic's Corner, RE: Michael Fremer seems to be implying he has an erection after looking at girly pics? .. (0.00)
Posted by LinuxGuru on 2009-10-25, 04:38:22 (83.99.214.85)
I found most these covers nice looking and aesthetically pleasant. As for physiological reaction of the mentioned above person, we should be glad he enjoys them :-) IMHO it says nothing bad about hes .......
460: Tube DIY Asylum, RE: SANSUI AU-111 (0.00)
Posted by LinuxGuru on 2009-10-25, 04:29:07 (83.99.214.85)
I have AU111 service manual. If you want one please PM me. As for PS filter caps, I would recommend 105C rated Panasonic, Epcos or Rubicon. You can stack the together to build multi-section caps with .......
461: Whiner's Woad, RE: You're a computer "guru" (0.00)
Posted by LinuxGuru on 2009-10-23, 00:57:12 (83.99.214.85)
The original post was deleted. Are you sure its possible to search a phrase I do not know a single word from? Is there a new type of search engine that can read someone else mind upon my will? ::: TOP .......
462: Whiner's Woad, RE: I'm leaving (0.00)
Posted by LinuxGuru on 2009-10-22, 15:17:07 (83.99.214.85)
Hi, JustJoe! Would you please e-mail PM me this link? Thanks. .......
463: Tube DIY Asylum, RE: Opinion on resistors (0.00)
Posted by LinuxGuru on 2009-10-13, 14:54:38 (83.99.214.85)
I do not think resistors contribute any meaningful degree of sonic signature. Any blind tests that can prove opposite ??? I prefer Vishay metal film resistors, for low temperature coefficient reason. .......
464: Tubes Asylum, RE: Audio memory being what it is (0.00)
Posted by LinuxGuru on 2009-10-13, 14:50:28 (83.99.214.85)
Hi, Amandarae, What high-efficient speakers do you use? Klipsch, Technics, Sansui, Kenwood ? .......
465: Tube DIY Asylum, RE: Valve amp DIY (0.00)
Posted by LinuxGuru on 2009-10-11, 11:36:35 (83.99.214.85)
Occasionally I have found a proven schematic for 1250W vacuum tube amplifier. It was an industrial grade Russian monster used to power up very large rooms (e.g. dance clubs) and even small cities, it .......
466: OTL Asylum, RE: Regulated Power Supply ? (0.00)
Posted by LinuxGuru on 2009-10-09, 10:12:50 (83.99.214.85)
I will build one, regulated/stabilized 490V 500mA for my new project, with 6.3V/10A DC filament supply for audio tubes. I'm trying to negotiate order of custom toroidal 500VA power transformer, withou .......
467: Tubes Asylum, RE: Marantz 8b vs Mcintosh MC225 (0.00)
Posted by LinuxGuru on 2009-10-09, 00:20:56 (83.99.214.85)
> suggest a book if you'd be so kind. No problem. 1) Rectifiers and stabilizers, Gosenergoizdat 1951. 2) Voltage multipliers. Gosenergoizdat 1952. it is so called MRB series (published since 1947), ti .......
468: Tubes Asylum, RE: Marantz 8b vs Mcintosh MC225 (0.00)
Posted by LinuxGuru on 2009-10-08, 13:54:11 (83.99.214.85)
> many people don't realize that in a doubler,the power > transformer has thicker wire with a lower turns ratio and > ultimately less resistance so when you think about it,that > can be a big plus bes .......
469: Tubes Asylum, RE: Marantz 8b vs Mcintosh MC225 (0.00)
Posted by LinuxGuru on 2009-10-08, 13:30:52 (83.99.214.85)
> Sounds like you don't understand how to design > voltage doublers then ;-) Look at VA loading curve of full-wave voltage doubler in any book. Yes, you can make it "flatter" with large caps, but its .......
470: Tubes Asylum, RE: Marantz 8b vs Mcintosh MC225 (0.00)
Posted by LinuxGuru on 2009-10-08, 11:52:37 (83.99.214.85)
Almost all vintage tube amp use voltage doubler for B+ supply - the worst power supply in terms of performance and ripple. I'm going to replace this crap in my vintage amp with R-core or C-core custom .......
471: Tube DIY Asylum, RE: TT100 (0.00)
Posted by LinuxGuru on 2009-10-04, 04:31:14 (83.99.214.85)
If you need very powerful amplifier you should use KT90, KT100, or Russian 6C33C/GU29/GM70 valves. Designing tube amp from scratch is not a good idea, better to use proven and tested schematic. ::: TO .......
472: Tube DIY Asylum, RE: Valve amp DIY (0.00)
Posted by LinuxGuru on 2009-10-04, 04:25:25 (83.99.214.85)
Is this home or guitar amplifier for outdoor/night club use? These are VERY different types of amplifiers. Please be more specific. PS. I'm barely use over 0.5W per channel at home, so 400W for me loo .......
473: Tubes Asylum, Power Transformer Kaput ??? (0.00)
Posted by LinuxGuru on 2009-10-02, 10:38:29 (83.99.214.85)
I have Pioneer SM-83 vacuum tube amplifier, and few days ago I have noticed smell of burning oil or whatever else material used for paper impregnation. Pioneer power transformer uses a lot of layers o .......
474: Tube DIY Asylum, RE: KH-Audio (0.00)
Posted by LinuxGuru on 2009-09-21, 15:02:27 (83.99.214.85)
Is this the www.kh-audio.com ??? .......
475: Critic's Corner, RE: Acoustic Energy Evo One (0.00)
Posted by LinuxGuru on 2009-09-14, 11:13:55 (83.99.214.85)
Hi, Bill! I have tried to e-mail you but your server rejects messages. Please PM me your e-mail address (not billmali - at - vsnl - dot - com). .......
476: Critic's Corner, RE: Acoustic Energy Evo One (0.00)
Posted by LinuxGuru on 2009-09-14, 00:18:25 (83.99.214.85)
Please PM me, i'll get back with feedback. Room 13x11x9 - is the ceiling 9m high? .......
477: Critic's Corner, RE: Am beginning to love Mahler #4 but... (0.00)
Posted by LinuxGuru on 2009-09-13, 13:27:39 (83.99.214.85)
I think the main point is your speakers, and their placement in the room. Contrubution of the amplifier to the overall sound quality is not that important as many believe. What speakers do you have? : .......
478: OTL Asylum, RE: Schematic CAD (0.00)
Posted by LinuxGuru on 2009-09-11, 13:06:39 (83.99.214.85)
Can you please post URLs for tube models for LTSpice ? Thanks in advance ! .......
479: Tube DIY Asylum, RE: why paper in oil caps sound so good and smooth (0.00)
Posted by LinuxGuru on 2009-09-06, 04:43:50 (83.99.214.85)
> Duelund broke all the rules about capacitor design > and smoothness and fluidity with most perfect detail > from their PIO caps. That's why I feel they win all > cap comparisons and are way ahead of .......
480: Tube DIY Asylum, RE: 6.3V/5A DC Fillament Schematic (0.00)
Posted by LinuxGuru on 2009-09-04, 14:02:50 (83.99.214.85)
Looks like there are 2 very simple choices: 1) 5A IC voltage regulators, LM138/238/338, and LM1084 2) High-Efficiency step-down switching voltage regulators, like LM2678 LM2678 requires much much smal .......
481: Tube DIY Asylum, 6.3V/5A DC Fillament Schematic (0.00)
Posted by LinuxGuru on 2009-09-04, 12:14:40 (83.99.214.85)
Anyone have ready to use schematic of high-efficient stabilized DC filament 6.3V/5A? It will be used for integrated amp with 7 x 12AX7 (6N2P-EV) tubes which includes phono-preamp (very sensitive to hu .......
482: Tube DIY Asylum, RE: Can you leave one section unused on a can cap? (0.00)
Posted by LinuxGuru on 2009-08-30, 04:48:10 (83.99.214.85)
Absolutely. .......
483: Tube DIY Asylum, RE: Recommended circuits for MC pre-pre amp (0.00)
Posted by LinuxGuru on 2009-08-30, 04:47:27 (83.99.214.85)
Try Marantz 7C phono pre-amp, built around 3x12Ax7. Use Sovtek 12AX7LPS (long plate spiral filament) for low-noise operation. .......
484: Tubes Asylum, RE: Anyone familiar with the tube testing service by eBay seller hlfltubes? (0.00)
Posted by LinuxGuru on 2009-08-30, 04:41:32 (83.99.214.85)
It depends how much pcs you have of these tubes for sale. If 1 - 2, yes, it may be OK to give away 25%. BTW, I think Jim McShane or Mike Samra can test these tubes for you, It will not be very expensi .......
485: Tube DIY Asylum, ??? Output Transformer - Silicon Steel or Amorphous (0.00)
Posted by LinuxGuru on 2009-08-27, 08:37:56 (83.99.214.85)
Hi, Tube folks, Currently there are 2 major flavors of audio output transformers (both SE and PP) - with silicon steel and amorphous nanocrystalline cores. Amorphous cores are ferromagnetic alloys bas .......
486: Tube DIY Asylum, RE: My latest build (0.00)
Posted by LinuxGuru on 2009-08-22, 03:56:50 (83.99.214.85)
Hi, Tre! How much cost pair of ElectraPrint Partial Silver OPT? Did you used NOS or new production 300B? .......
487: Vinyl Asylum, RE: Mitsubishi LT20 Question (0.00)
Posted by LinuxGuru on 2009-08-15, 10:44:37 (83.99.214.85)
Thanks for so valuable info! What was the name of this IC? Is this something generic, or proprietary Mitsubishi Electric? Dave, may be you still have service manuals for Mitsubishi turntables lying so .......
488: Vinyl Asylum, RE: I don't have one, but (0.00)
Posted by LinuxGuru on 2009-08-15, 09:55:40 (83.99.214.85)
Thanks for anyone who come with feedback! reelsmith, may be you still have service manuals for Mitsubishi turntables lying somewhere? .......
489: Vinyl Asylum, Mitsubishi LT20 Question (0.00)
Posted by LinuxGuru on 2009-08-15, 04:08:33 (83.99.214.85)
Hi, folks, Anyone have Mitsubishi LT20 turntable? If yes, what is your impression about its quality? Do you know which cartridge originally was supplied with LT20 or similar model (LT22, LT30)? ::: TO .......
490: Tubes Asylum, RE: Some tube gears at hi fi show(w/photos) (0.00)
Posted by LinuxGuru on 2009-08-15, 03:08:34 (83.99.214.85)
Very nice photos! May I ask to send them (full-resolution versions) to be e-mail ? .......
491: Tube DIY Asylum, RE: SS regulator for tube amp and reducing the B+ (0.00)
Posted by LinuxGuru on 2009-08-10, 13:01:40 (83.99.214.85)
I think you can use the one desgned by Jan Didden. http://www.linearaudio.nl/t-reg-1.htm .......
492: Tubes Asylum, RE: Yet another EL34 based amp sucuums to the 6N3C-E tube. (0.00)
Posted by LinuxGuru on 2009-08-10, 12:59:31 (83.99.214.85)
Mike, can you please try 6P3S-E in another EL34 based amp, like Maratnz 8 or 9 for example, and share your experience? Thanks to your research effort, I have now 20 of them, and my next project will c .......
493: Tubes Asylum, RE: 6H6c = 6N6P (0.00)
Posted by LinuxGuru on 2009-08-10, 11:17:12 (83.99.214.85)
> The better versions of the 6N6P are the ones > with the OTK military acceptance stamp, OTK did not meant military-grade stuff, this sign was even put on the bottles with milk and boxed cheese. OTK i .......
494: SET Asylum, RE: hand-wound transformers (0.00)
Posted by LinuxGuru on 2009-08-10, 08:08:50 (83.99.214.85)
100% handmade are better? This is belief which does not have any scientifically proofed factual background. Anyone can really wound bifilar coil by hand ??? BTW, all audio transformers require some de .......
495: Vintage Asylum, RE: Marantz 7c line stage (0.00)
Posted by LinuxGuru on 2009-08-09, 14:53:43 (83.99.214.85)
It is not high-priced collectible, but from the point of view of sound reproduction quality, it is the same pre-amp. Any audio gear is bunch of parts connected according to schematic, there is no hidd .......
496: Tube DIY Asylum, RE: Deoxit 5 Pump Spray WARNING!! (0.00)
Posted by LinuxGuru on 2009-08-08, 06:55:57 (83.99.214.85)
Just take a look what this deoxits do to the oxidized metal surface and dirt, and think what happens when this vapor condenses inside humans breath system. Tissue surface cells will be at least intoxi .......
497: Tube DIY Asylum, RE: Audio Note UK and Audio Note Kondo (0.00)
Posted by LinuxGuru on 2009-08-03, 13:45:25 (83.99.214.85)
Hi, casouza! Actually SET was the first amp I heard when arrived in this world thanks to my mom and dad - it was built into our family Having heard other SETs I can only say some have very deep and pl .......
498: Tubes Asylum, RE: Military tubes and capacitors and other components (0.00)
Posted by LinuxGuru on 2009-08-01, 05:03:33 (83.99.214.85)
Mil specs may mean different things, from highest quality material to resistance against radiation. I do not think the latter will contribute anything to the sound quality. Yes, components built with .......
499: Tubes Asylum, RE: Salute to Jim McShane (0.00)
Posted by LinuxGuru on 2009-08-01, 01:42:18 (83.99.214.85)
Jim's service is a top-grade, no questions. .......
500: Tube DIY Asylum, RE: Tribute Transformers order delay (0.00)
Posted by LinuxGuru on 2009-07-31, 11:56:26 (83.99.214.85)
Is this from: http://www.tribute-audio.nl/ ??? How much you paid for them? What is so special in these transformers? IMHO you should cancel order and request money back. Try to send e-mail from diffe .......
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