My father in law built me an amp awhile back, and it worked great until I started using pedals. When I turn on my amp with my pedal chain hooked up it does a "looping click" sound through my speaker but not all the time. My father in law used the term "chasing it's own tail". He has fuses hooked up to the speaker output from the amp so it will safeguard any damage to the speakers. I keep blowing those fuses after I get that feedback loop (amp shows signal but no output sound to speakers). It is a pretty high gain amp but why does this keep happening? Currently I am using a EHX Bass Preacher, BBE Sonic Stomp Maximizer, and JHS Jet City Boost/Overdrive. I have taken each of them out of the chain, tried different cables, different order and the only thing I came up with is the bass preacher has some extra noise to it than the others. Can't narrow down why either, doesn't seem consistent. My father in law isn't a musician, he is an electronics guy who has built amp and cabs for 30 years, more PA type stuff and some guitar stuff. Is he not building to cater to a bass player? Do I need a hum cancelling pedal or noise gate? Any input would be appreciated.