I recently got a Fender MIM Precision Deluxe Bass (active pickups, See Here). I am playing it through a Markbass Little Mark III (500w) and a Markbass Traveler 102p. First off, I brought all my gear into Guitar Center to test it (I got it shipped there used), and I couldn't recreate the problem there. At my apartment I get a weird fizzy/phase sound, usually on the lowest string only and mostly the lowest 3 frets, and only when I have the lows boosted (whether on the amp, or the guitar). If I boost the lows a ton then it carries over to the other strings some. Like I said, it didn't happen at GC. It did happen in multiple rooms at my apartment. My best guess is it's something to do with the power supply in my apartment. I got a Furman power conditioner and that didn't help the problem. I've tried multiple instrument cables, but only one speaker cable that I just bought. I've messed with the EQ a ton and I can get the problem to mostly go away but I can't get the tone I'd prefer. I'm wondering if there is anything else I might be able to do to help fix the problem? Is it likely that it's the brand new speaker cable, since that's the only thing I didn't try multiple of/bring to GC to test? Thanks.