I used to own one of these years back and regretfully sold it and just picked up one used. When I plugged it in to my cab the amp has a very pronounced power supply hum. It's like a low B flat on the A string and quite annoying. I think I would have remembered this. I swapped all the tubes with known good ones from my other amps and it still hums. My tech took a quick look at it and felt it was fairly noisy for such a low wattage amp. He also noticed that one of the screws on the power transformer was not the same which is a little suspect. Anyone?