Hello All, I own a Peavey combo115 that i bought used a few weeks ago. Up until today i had no problems with it. Last night i was practicing and a loud pop sounded. Then the amp started buzzing/humming. At first i thought the jack on my bass was loose but it wasn`t. I disconnected the bass and turned all the knobs to find the source of the noise. The only thing that i found was when i turned the post gain knob the noise changed volume slightly. I have no idea what is causing this noise,but it`s driving me nuts. If any of you have any advice, i would be ever so grateful to hear it,THANKS!