Pars

Not sure Mikey. I'm not really up on any of the current cabling guys like Moon Audio (see some hits for these phones with Silver Dragon cables on them). It would be nice if AT said what they would or could do before you sent them in From the pic, it looks like it is just heatshrink that is splitting, but as you say, getting access to a free end to replace it is problematic unless you can remove the cable at the headphone end.

Now there is a HC approved overkill transformer! The two trimpots on the GRLV by the output terminals are for balancing out the output voltages.

The voltage selector switches I normally see used are C&K, mouser pn 611-V80212MS02Q. Other flavors available; this one is the straight PC mount version.

Maybe just put a voltage select switch right on the board as well, and only have 2 AC in (L/N)? EDIT: Also note that the 35VA/50VA trans use 1.3 mm pins, larger than the others.

Yikes! Glad I never looked into buying one then. I'd never read anything about them to this level of detail (such as the rails having to sequence correctly). That said, when it does work, how does it sound?

Damn, I could use one of those behind our couch...

RIP Eddie. Never a fan, but this absolutely sucks.

Interesting Craig. Per the bold, I was always interested in hearing one of these. What do you think of it? Guessing since it is on the phono and Dynalo, and not on the T2 that you prefer the Audio Synthesis.

I'd steer clear of the "audio" grade caps and go for good 105C rated ones (Panasonic, Nichicon, UCC, etc.). I can't help with your other questions.

RIP Helen and Mac Davis. I still remember Mac with Nick Nolte in North Dallas Forty... I also laugh when I remember the alternate parody lyrics to "I Am Woman" that I saw somewhere years ago.

Just a couple of comments: The sockets you used for the opamps are shit. Machined pin sockets such as Mill-Max 110-93-308-41-001000 are greatly preferred for reliability. The terminal blocks look suspect. Normally, Phoenix Contact terminal blocks are used. Did you check the voltage ratings on the ones you used, compared to what you are running through them?

Happy Birthdays!

The 5pf caps I had in my BOM were Mica (598-CD17CD050DO3). Kevin's BOM (old one) used COG ceramics (81-RDE5C1H5R0C0K1H3B). As for the 20R resistors, try them as long as they are appropriately sized. I'm not too much of a fan of the PRPs anymore (coating comes off easily). Never used Takmans. I've been using the Vishay/BC MRS25s for some stuff and have liked them.

These are the Wimas I had in my BOM for the 4.7uf caps: MKS2C044701M00JSSD The solid polymer cap might be interesting as well. I hadn't realized they make these that large these days. Something like these 63SXE100M Panasonics or these HHSD630ELL101MJC5S UCCs could work. EDIT: IIRC, some variants of the boards were missing the ground plane connection to one or more of these caps, so check that as well. And you would never find polypropylene (PP) caps this large of value/voltage rating in something small enough to fit here. A Wima MKP4 cap of this value has a 27.5mm lead spacing.

Happy Birthday Jim!

RIP Gale. I used to love watching him run in the '60s.

My condolences Jose.

My condolences Jeff to you and your family. 92 is a pretty good run.

Good to know. Thanks guys!

Thanks! I was wondering if there was a sonic difference between the 470uf and 680uf. At 550V, these are huge caps energy wise. The 60mm height and a 2U enclosure would sway me to using the 470uf, but I'll have to ask the guy I am building this for what his preference is. Paging @mwl168, but I think he used something similar to a Modushop Slimline, with beefy sides but not heatsinks for his universal power supply case? IIRC, he had told me that the Carbon amp boards toss a bunch of heat, but the PSUs aren't that bad? Since this will be a 2 box build, with a universal tube/SS PSU, if that is the case, I still think I would go for the 470uf caps. We'll see...

Fuck indeed. RIP RBG... truly great.

Thanks James! Yes, I had noticed the cap size; the 60mm is appealing for a 2U chassis. It will have inrush limiting; initially CR60 or 90 thermistors. Four of the 470uf are actually slightly more than the two pairs of 680uf, but the price isn't an issue.

This topic has needed its own thread for quite some time (years), so starting one. I may see if I can get a mode to move some of the posts here (Carbon thread, not sure where else they are littered). 11 hours ago, Pars said: GRHV question: I'm building a pair of the singles intended for 400V output. On the BOM I have, there are 2 680uf caps for each board; 1 is a 550V caP, the other a 450V cap. I presume the 550V would go right after the rectifiers in the schematic, and the 450V on the output. The BOM that was posted by jamesmking uses 4 x 470uf 550V Kemets. Is there much difference between the 680uf and 470uf in terms of sound or anything? BTW, I think I had mentioned this before, but the GRHV really deserves its own thread. Confusing to have to weed through the Carbon thread, and I don't know how many other threads with GRHV posts in them.

GRHV question: I'm building a pair of the singles intended for 400V output. On the BOM I have, there are 2 680uf caps for each board; 1 is a 550V caP, the other a 450V cap. I presume the 550V would go right after the rectifiers in the schematic, and the 450V on the output. The BOM that was posted by jamesmking uses 4 x 470uf 550V Kemets. Is there much difference between the 680uf and 470uf in terms of sound or anything? BTW, I think I had mentioned this before, but the GRHV really deserves its own thread. Confusing to have to weed through the Carbon thread, and I don't know how many other threads with GRHV posts in them.

Happy Birthday Stretch! Try not to drink to much wine (or whatever), and hope the air is getting better.