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The reference voltage of 10V comes from the Linear Technology LT1021DCN8-10#PBF. You normally won't need to measure this unless you have problems with the output voltage. You don't need to worry about transistor or diode matching on these. If you like, use 0.1% low tempco resistors for the R7-R10. You will get acceptable +/- voltage tightness with 1% resistors, particularly if you match those. No. Just use the specified Wimas with the 220uf Panasonic electrolytics and you will be good. Do not buy that cap from Partsconnexion and ignore all the audiophool bullshit. I never test these loaded, and I don't think you need a variac, particularly if you pay attention when building (right part in right place, etc.). I've never used a variac with a GRLV even though I have one. Just make sure you have your desired +/- 20V before connecting an amp board, and you should be fine. DItto.

Happy Birthday!

James, all: Nice writeup BTW. Correct me if I'm wrong, but I believe you can use a dual secondary transformer as a CT simply by tieing the two secondaries together? http://engineering.electrical-equipment.org/wp-content/uploads/2013/07/Dual-Voltage-Transformers-1.jpg All of the GRLVs that I have built use dual secondary transformers and dual bridges, and I don't foresee a reason to use the single bridge for one.

oops...

Kevin retired from Northwestern Univ. (the .edu links) a few years ago, so those links are no longer valid. The Stax thread will provide google drive links to the board files and other documents. For a Dynalo, you will want +/-20V for the GRLV. There are BOMs for the GRLV posted in the thread. Sorry, but we don't provide build guides, etc. here. Going thru both the Dynalo and the Golden Reference LV threads should provide you with all you need to know. Build the GRLV first, and test it unloaded to make sure it is performing properly. Pretty easy build. And I would stay out of the and now for something completely different part 3" thread for now. The Dynalo is a very good amp. Not sure what phones you are intending this for, but the CFP 2/3 is a very good amp.

No, they won't work correctly backwards, as it basically flips the N's and P's, and those will be in backwards as well (emitters/collectors). Barring having a "1" marking, the pad for pin 1 should be square vs. round for the others. From what I recall, putting a similar JFET module in backwards resulted in nasty DC offset. I never tried to see if any sound came through or not. The seller of diyaudio of these does provide genuine devices. Also, it should be noted that a similar adapter for dual JFETs (2SJ109/2SK389) will not work for bipolars (SA1349/SC3381) as the pinouts are different, even though they use the same device package. Yours are marked for the bipolars, so should be good. Is the distortion in both channels?

Did you remove or re-install these after bringing the amp out of storage? From your pic above, pin 1 doesn't seem to be clearly marked, so the potential for putting these in backwards is there. Also, have you tried it with the THAT340s?

You could always use something like the Pi2AES that SBAF seems to recommend.

Good NOS (heh) 6922s are probably rare as hell anymore. When I used to have a tube preamp (Counterpoint SA5.1) 10 years ago, I had a pair of Amperex PQ white label 6922s in it, which I really liked. The EH 6922 gold pins are quite good. If you can manage to find some vintage, you will pay out the nose for them, and possibly get ripped off. Some seemingly decent recommendations for dealers here: https://www.thegearpage.net/board/index.php?threads/online-tube-dealer-sticky.1197164/

Another pot or stepped attenuator I have worked with (on Todd's CFP3) is a 41 step unit from Acoustic Dimension. It seemed pretty nice with good tracking, etc. The do make quad units, and the one in the CFP3 was a 10K, which they don't show on their website. http://www.acoustic-dimension.com/

Happy Birthday Jose!

Happy Birthday Greg!

Happy Birthday Justin!

Oops, sorry. No, I got the unit in fine shape. I like it very much! That said, I don't use it a lot as I haven't been playing DVDs/Blurays much lately.

New Garbage

Happy Birthday Kerry!

Sorry, don't know where to find either, but in general, for any of the designs using old silicon, it is a good idea to source all of the silicon, or at least make sure you can, before investing in PCBs, etc.

A 14+ year necro thread... not an auspicious first post.

Haven't looked at the schematic, but 30V secondary would produce 30 * 1.414 = 42.4 V raw DC, less the rectifier drop (1.4V for full wave). So if the caps are right across that, 25V isn't going to live long. Looked at the schematic, and the caps are right across the secondaries after the bridge. A 30-0-30 seems rather excessive for a +/- 12V supply. 15-0-15 would have been a better choice.

Sorry for your loss Todd.

Yeah, I had heard some negatives regarding him (and his thumbprint on the show) before the series started, but went ahead and watched it anyhow. I can't say I've been a big fan of his (watched Dollhouse, but never really watched much of his other stuff). Apparently he isn't involved with the show since the first few episodes.

Hmm, the datasheet right off of Genesic's site shows GDS: https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwi5usK-kvnwAhXKZs0KHYmTCvMQFjABegQIAxAD&url=https%3A%2F%2Fwww.genesicsemi.com%2Fsic-mosfet%2FG3R450MT17D%2FG3R450MT17D.pdf&usg=AOvVaw1sVqBXJV-AnV_PZztKUbPF Now this is confidence inspiring! Newark's is GDS Arrow's is GSD

Has anyone been watching "The Nevers" on HBO? I have, and while it has many problems and is kind of a mess, have been enjoying it. Joss Whedon, who I know has a lot of fans here.

When you say "then I replaced all the internal cables with 2.5 mm section OFC. I didn't think the sound changed so much for the better, I don't recognize them anymore." do you mean you like them better, or they sound worse? And yes, pictures or it didn't happen.

I'm watching it as well and like it.