Need a little direction in forum. Can't find answer to problem in SB thread after 30 minutes or so, I have a very noticeable hiss. On the vintage side, no hiss if I roll mid and treble off. On overdrive side, has hiss regardless of eq settings. Autobias says power tube OK. I assume probably preamp tube. Any way to isolate it further? Just bought the amp and love it. No idea how badly abused it may have been. I'm sure the answer is here, but just can't find it. Thanks in advance
One more thing I noticed when playing today, the hiss is very intermittent. Will be there one second then gone the next. It will sometimes last for several minutes