After sitting idle with the RED channel engaged, it started working just fine. Next morning, the same behavior with the GREEN channel working and the RED channel with dead silence. So perhaps a warm up makes it work. Again, would still like to get some idea of internal layout so I can...
I own a Syn-1 with a Friedman BE two channel module. I mostly use the blue channel with max gain. Recently I switched to the RED channel and there is no sound. I switched out the module with another I own and both channels work. I wasn't sure how the pre-amp tube layout works so I tried...