Well, my grandson ended up staying over for the weekend, so I didn't get a chance to dig in like I thought I would; but, although I didn't yet try any of JM Fahey's recommendations, I did spend an hour before going to bed and 2 hours before going to work (my shift is noon to 8pm) trying a couple of things.
I hooked up the limiter and the amp, plugged a guitar into a looper and let the loop run, hoping to see what the light would do when the humming started.
Very interesting: the symptom does not appear when plugged into the limiter. Or at least, it did not show after 45 minutes. Then I plugged it back into the wall and the symptom re appeared after 10 minutes . I turned the amp off and checked for the smell. It wasn't too strong but I noticed something else: the heat seemed to be coming from around the Q308-Q310 area.
Tonight, I'm going to go through Mr Faheys recommendations and also check the soldering on Q308, as per teemuk's service manual contribution. I'll keep you all posted and thanks a lot for the help.
I hooked up the limiter and the amp, plugged a guitar into a looper and let the loop run, hoping to see what the light would do when the humming started.
Very interesting: the symptom does not appear when plugged into the limiter. Or at least, it did not show after 45 minutes. Then I plugged it back into the wall and the symptom re appeared after 10 minutes . I turned the amp off and checked for the smell. It wasn't too strong but I noticed something else: the heat seemed to be coming from around the Q308-Q310 area.
Tonight, I'm going to go through Mr Faheys recommendations and also check the soldering on Q308, as per teemuk's service manual contribution. I'll keep you all posted and thanks a lot for the help.