Loud Hum with effects

[majwild1]

While using my twin reverb, and my effects board I get a loud very annoying hum from my amp. if I remove the pedal board It's gone what could be causing it? power supply? I have narrowed it done to 2 pedals also if I remove them from the loop its gone. my big muff and a dod pedal. anyone ever have this problem. and also I've always been a fender guy but I got a good deal on a vox ac15 and I have to say that I like it.

[Pearly Grapes]

Try the pedals using batteries, no wall warts.
PG

[majwild1]

ok now this is really getting interesting, now the amp blew the slow blow fuse so I figured I would recap it and put it back together and sounded great ran it for a 7 hours no problems at all, while I was out of town our other guitarist used it was working fine, and the bang popped the slow blow again. any ideas where I should start? the tubes are not that old tad 6l6 copy of the rca black plate I'm running the bias at 36ma so not hot.