GeorgeP

Weren't they using both 6922 and 6dj8 at the same time?

I always get confused by this whole some 6ca7 tubes are pentodes (relabelled EL34) and some (the fat bottle Sylvania/GE) are beam tetrodes. Not sure which was the intended one for theT2. But if there is cheap current production source of tubes that sounds better than all the new production "el34" tubes, and doesn't blow up the t2, then colour me interested.

Use 10k pot to adjust to 6.55v across the 22k, then use the 2k to adjust the rest of the way - do this for the ones you already set as well.

Sent you an email on this a couple weeks ago - you don't use the 10k to get to around 740, you use it to adjust the voltage across the 22k resistor. Otherwise you are basically doing it with your eyes closed.

slow and steady wins the race...

Do you mean the LEDs on the amp board? In any case that should not be happening. Only the filaments should be on (constantly), and not flashing.

You don't need any shielding. I have made umbilicals with and without, including bundling the heaters separately and could detect no difference.

If I were you I would send my Omega to this outfit. I have never heard anything negative about them. That, and maybe read your welcome pm.

It is 12v, and what is the 500v for?

Am surprised he actually posted these pictures instead of falling into a deep depression after realizing he paid thousands for it...

The original was made by Hitachi. Renesas is the good. Not sure of any differences, but I suspect if you are seeing this "readily available" its because fakes are readily available.

I thought the bright yellow rubber bands did a wonderful job of bringing out the highlights in his eyes. Not sure he needs to improve upon it any further.

^this, given some of the generous amounts of solder used in other areas shown in the pics. The excess solder sits on the trace and the mask eventually breaks down...

Oddly, wasn't interested in Tom Waits until I heard Black Rider in the early 90s - its the soundtrack from some German (I think) theatrical production - not his best, but my favourite.

No significant advantage, and onboard LV is certainly simpler.

Don't think you are using the opto servo - you only have the one jumper engaged next to the op27 socket. So this would explain your higher starting voltage I think.

Happy Birthday, Kerry!

kgsshvpssicfetnocap.zip

So answering my own question - there are no other considerations, and it works like a charm. Regarding the off-board PSU PCBs, for anyone interested the errors are shown in the pics (also, various values have changed, but the circuit is the same):

Other quick question. Was going to use 2 +400 PSU boards (cap off-board version), making one to output -400. From what I can tell looking at the schematic, all that I need to do is output one of the +400 boards to ground to get -400 out of the ground terminal. Don't think there are any other considerations to keep in mind. Using a GRLV and separate bias board as well. And as an aside, there are two errors in the cap off-board psu - will post a picture later on.

Great, thanks, John!

Has anyone use the Carbon amp board with ground plane (version .6G)? Wanted to know if people have had successful builds with these and there were no board errors. Have a couple sets, not sure from where with all the board ordering over the past year, and thinking of building one.

You might be the only person who built one using that board - 4oz copper and super thick makes for a tricky build and zero tolerance for error. Did you diode test the whole thing? Also, is the right side the one that was missing the trace?

That has been my experience as well.

What is yours doing? If I recall you have the shrunk board from the failed lil knight group buy. Interestingly, I cannot recall reading anyone who has had any issues with the corrected boards, until now. Even S_R's first build, using the same board iteration, had no issues.