high voltages at OA and OB [resolved]

[mishak]

Hello all.  Just want to say I've loved my BHC the past year, and this amp is pretty wicked!

I purchased it with the SB 1.1 upgrade, and as advised, I used BHC without speed ball for about a year.  I added the small PCB this weekend and used the amp without any issues after "stage 1" of the SB upgrade.  Today I decided to add the larger PCB part of the upgrade and initially the two LEDs on the OB side of the PCB weren't lit up.  The voltages were off, and I re-soldered some joints and then they lit up just fine.  When checking voltages, OA is reading around 115 and OB around 110.  I tried reheating the TIP-50 legs again and added a bit more solder, however the voltages are reading the same.  The amp is working fine currently, but I just want to make sure its OK.   Thank you all in advance. 

[Paul Birkeland]

What are the OA and OB voltages on the small board?  I would suspect that they are a little on the high side, and that may be moving the voltages at the outputs of the big board up a little as well.

It's also worth mentioning that a really, really strong 6080 will show a greater difference in voltage between the OA/OB on the small board and the OA/OB on the big board. 

[mishak]

OA and OB on the small board at 85 and 79 respectively

[Paul Birkeland]

Yeah, so that's a little high.  I wouldn't be concerned about what you're seeing.  You have a 12AU7 that's not super fresh (but totally within normal operating specs) and a 6080 that's got strong emission.  The two in concert are pushing those OA/OB voltages on the big board up a little bit.

[mishak]

thank you so much for the prompt reply!