Whenever I use the effects loop, I get ALOT of hiss, only thing going in there is a boss eq and delay stomp box. I have the selector set to minus 10 DBs even. but if I remoove all effects from the loop, I still get the hiss. When I push in the bypass button, no fx or not, the amp is super quiet. This occurs even when the amps master is turned to zero. (preamp vol is dimed). HELP?