MKIII???

[boogietone]

I'm getting a low feedback/hum that starts off real quiet and gradually builds until you turn the master volume down. As the feedback/hum gets louder it builds more rapidly. And it gets LOUD. It is doing this anytime the master volume is around 2 or higher. The other volumes do not seem to make much difference. It does this with the guitar not even plugged into the input. I did notice though it immediately stops as soon as I unplug the patchcord going to the effects return. Any ideas?
Thanks in advance!

 

[Schmoog]

I would concur with the bad patch cable in your effects. start with the effects RETURN, and unplug them going backwards towards the send, when you unplug one that doesn't stop the hum, that means the one in FRONT of it (return side) is the bad cable.

 

[boogietone]

Holy crap you guys are geniuses. I never thought to check the patchcords. Good thing I just work on helicopters for a living! Anyways, problem appears to be fixed. I was thinking it was going to be a tube somehow. Thanks!