I have a 1973 Fender Pro Reverb that has been reconfigured to AA165 blackface specs. Channel 1 works great, channel 2 has a weak output. This amp had been heavily modified by an amature experimenting with Torres mods. I removed all the mods and rewired to AA165 specs, but cannot get the second channel to work. Have done all of the troubleshooting to eliminate issues with tubes, swapping etc. I've traced all the wiring from point to point, swapped tubes, checked for shorts and grounds.
When plugged into channel 2, vibrato channel, I have a clean but very low output. Kind of like the preamp by itself, until I turn up the volume on Channel 1 and then it gets dirty and distorted, but nowhere near the gain that I should have. Turning up the volume pot for channel two does not vary the gain very much; I can take it to 10 and it's not much different than if it were at 3-4, which is barely louder than picking the strings on the guitar alone. Channel 1 at that volume can disturb the neighbors if the doors were open.
When plugged into channel 2, vibrato channel, I have a clean but very low output. Kind of like the preamp by itself, until I turn up the volume on Channel 1 and then it gets dirty and distorted, but nowhere near the gain that I should have. Turning up the volume pot for channel two does not vary the gain very much; I can take it to 10 and it's not much different than if it were at 3-4, which is barely louder than picking the strings on the guitar alone. Channel 1 at that volume can disturb the neighbors if the doors were open.