I just sold my Mesa 400 and purchased a yorkville xs800 today. I didnt notice this problem in the store, but whenever i turn it on, now it makes an input like hissing noise (think disconnecting a cable while still plugged into the amp noise, but with static hissing and cracking too). Last time i used my mesa was on friday, and there was no hissing coming from my cab at that point. The thing that is weird is whenever I move the extendable lights on my power conditioner it crackles like something is affecting it, weather or not i have the power conditioner plugged in/on or i have an instrument cable connecting my stuff. Its set up as follows in a 6 space rack: power conditioner tuner yorkville 1 open slot I doubt that has anything to do with it, but im just covering all the basses. Ive tried both inputs in the back of the amp, and both in the back of the cab. Ive tried different wall outlets to make sure the power itself wasnt bad. I am baffled. What could the deal be?