thanks everyone for your input

does anyone know what it would cost to sent it in for service?

is it just the potentiometer that goes bad or is it a more difficult process. I would like to try and fix it myself if it is a simple part to replace.

i have a TI500.4 running bandpass with the front channels going to two sets of Focal components and the rear channels going to a set of TI 9" midbass. my problem is that i have a squeeling noise coming out of my right 9" midbass, i have unhooked the RCA's at the amp and the noise is still ...