I’ll try swapping the cables and see what happens.
Swapping the tubes is more of a hassle because I have to remove all the tiny screws from the chassis and remove the cover, but it’s worth a try
Interestingly though, I had a several hour listening session with a friend today, and after everything was warmed up, the problem disappeared and everything sounded great.
So It appears to be a warmup problem, which leads me to suspect the anomaly is caused by the preamp, perhaps a weak tube.
Swapping the tubes is more of a hassle because I have to remove all the tiny screws from the chassis and remove the cover, but it’s worth a try
Interestingly though, I had a several hour listening session with a friend today, and after everything was warmed up, the problem disappeared and everything sounded great.
So It appears to be a warmup problem, which leads me to suspect the anomaly is caused by the preamp, perhaps a weak tube.