Im a first time poster on this forum, and I hope I am asking this question in the correct area. Here is my question. I am running a Hartke HA4000 amp with an Ampeg B-410HLF. I re-wired my cabinet back into a 4 Ohm setting with new eminence speakers. I am not having any trouble with live sound. My trouble is coming from when I am in the studio or in larger venues where I have to run my balanced out to a board or PA. I am getting a very low static sound through my output. I have tried the ground lift etc and other guitar input jack, but to no avail. I have taken the amp to 2 different amp techs and they say they have pushed the amp through their systems and cant re-create the hum or fuzz. Is there a gounding system in the cab that can cause this problem or is the problem with the Hartke head? I have a huge gig with a national act in 10 days and if I cant get this handled I will have to drop some coin on getting another head. Plz help ASAP! I am playing a 2008 Fender MIJ Jaguar Bass and have went to the extent of changing the jack in the bass as well thinking maybe there was a grounding issue with the guitar but didnt fix the problem. HELP!