Ampeg V4 questions on cap value

[DrGonz78]

Okay here it goes... I put in a 20k bias pot in series with R215 and now my bias voltage is at -39.2v. Each tube is at 32.1ma 33.6ma 32.7ma 31.9 on my bias probe and plate voltages on each plate is right around 557v. That was my first try setting the bias pot with a guess as to where it should be set. So I am just right around 60% max tube dissipation. I think I am happy with that for now but what do you guys think? If I set the the tubes cooler closer to 50% that would be good but then my plate voltage will go even higher. At least this is all way better than it was a few days ago and I learned some good stuff so far. Let me know your opinions at this point and what else to check, thanks guys!!

[g1]

Sounds like you are more in the ballpark for plate voltage now. But don't worry about it too much, remember the V2 is running plates at more like 590V. If none of the caps are in danger from the higher voltage, you could still reduce the idle dissipation if you want. I think the tubes will be more susceptible to over-dissipation than to over-voltage. Out of curiosity, what is your line voltage?

[The Dude]

Not the best tube matching, but acceptable. IMO, that is about the right bias level for this amp. If you are happy with how it sounds and everything works as it should, I would call it done. Nice work!

[DrGonz78]

You know the amp sounds freakin' amazing!! If it aint broke don't fix it any more! lol These amps are a real beast to work on, but it is a real treat to get it working again. Thanks again you guys for all the help along the way, it really paid off.

Edit: Line voltage at night when I work is always really stable at 120vac so that has always been a good thing. Nights are not so cold lately so not so many heaters cranking away in the area. So yes it could be a touch above 120 at times but every time I measure it is basically 120vac.