I've got a new setup that requires having gain trims at the power side of the equation and I'm wondering about the best way to match gains on the two channels of my ST-70. They aren't miles off ~ 1-2 dB. The gain difference doesn't follow the 7199 tubes or the EL34's. I'm considering just replacing all of the resistors as they are old carbon comps. I just thought I might put trimmers in somewhere to get it as tight as possible and adjust for variation in the tubes.
The filter caps have been replaced by an SDS board underneath (long ago by a previous owner).