I have a buzzing problem in my studio, and it only happens on bass guitars tone knobs. This has happened on many occasions now and I am getting tired of noise gating. When ever a bass player plays his bass with the tone knob turned to the more trebley side, I get a loud buzz through my DI channel and it goes through his amp too, and my mic channel picks up the buzz. This only happens on bass guitar (with tone on treble), doesn't happen on guitar players, vocals, drums mics. It usually happens when I run the bass staight to a preamp too. I just have no clue. I have a commertial space, all the recording stuff is on the same power source, and I use MonsterCable stage 2 powercenters. I only have a few lamps plugged in, that is the only thing I Could see being a problem, but if its only happening on the bass guitar then I have no clue. And I don't use a CRT.

Thanks
Bob