TL/DR: Is there any cure for noisy wiring in an old house that only affects bass amps? I have an aggravating issue with noisy amps I am hoping y'all can help with. All my bass amps have a horrific amount of noise, sort of like a 60 cycle noise; a buzzing humming sort of sound. This happens with any of my basses which are a mix of Jackson JS series basses with their humbucker pups with active pre's, 2 basses with SD "Active EQ" true active pups, one bass with SD "Lightning Rods" and an old Ibby TR series with stock passives. I have three amps, a Behringer BX1200 combo, a rack rig with a Behringer Bass V-Amp Pro into a Behringer iNuke1000 power amp and a Hartke LH1000. The V-Amp and the LH1000 are both with a Hartke 4.5XL. Any combination of amp and bass will produce this noise. I can squash it with enough of a noise gate in the V-Amp but I have to run the noise gate so high that notes have virtually no sustain and the tone takes on a serious "ringing" quality. Both the V-Amp and the LH1000 have Furman power conditioners in their racks and they draw their power through them. The combo just goes into the wall. I have tried using a 3-to-2 prong adapter to see if that made a difference, no difference, so I immediately pulled it. I have tried four different instrument cables, no difference. Interestingly enough, when any of the amps are started up there is no noise at first, but as soon as a note is played the noise comes in like a madman. Now, this ONLY happens at my house. The house is old, it was built in 1916 and wired for power in 1941. With knob and tube. Because of that, all the bulbs in the house are CFL's, incandescents would only last a very few hours before blowing. The house has had wiring added on over the years, and has a relatively modern breaker box. My amps are plugged in on the newest circuit that I wired in about 18 months ago and I know it is grounded to the ground bar in the breaker box properly. I do not get this noise at church where I play, or at my local music store, so I know its a combination of the old wiring and all the CFL's in the house. Oddly enough my guitar rig, a Boss GT-10 into a Behringer KX-1200 does NOT exhibit the same symptoms, even when powered from the same circuit. I have swapped cables from the guitar rig into the bass rig and the noise persists. My question is, "Is there anything I can do about this before we re-wire the whole house in a couple years?" Flame away.