Originally Posted by meinl
Yes the buzz does stop when it is unplugged. I had noticed a buzz when I plugged it in a couple months ago when I tried plugging it in, but it was a smaller place and their PA stuff wasn't the best so I assumed it was a bad mic cable.
I have not tried the headphone out, but I will give it a try.
While the headphone out has an XLR jack, it's not balanced and for the DI on a board, it's not wired correctly. Pin 1 is always ground, pin 2 is hot and pin 3 is called 'cold' when pin 2 is called 'hot'. If you were to try making an XLR-TS adapter, you would combine pins 1 & 3, not 1& 2 and 2 isn't combined with 3 unless the manufacturer did something odd with the pinout.
I would open the amp and look at the XLR jack to make sure a wire hasn't come off.