Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: ernie_jr on May 28, 2019, 12:46:42 pm

Title: power rail resistors
Post by: ernie_jr on May 28, 2019, 12:46:42 pm

ok, so finally building my SUNN 200s with a second preamp from and Ampeg B25. In the Sunn, the secone resistor in the power rail is 33K, if I am adding a second 12ax7 would I drop the resistor to a 22K?
Thanks,
Ernie

Title: Re: power rail resistors
Post by: sluckey on May 28, 2019, 02:15:25 pm

I don't think you need to change value at all. However, I would prefer to add a separate B+ node for the Ampeg preamp. Like this...

Title: Re: power rail resistors
Post by: ernie_jr on May 29, 2019, 06:31:51 am

that works and is easy to do
Thanks Sluckey