Hey guys, So I just purchased an awesome 92 Ibanez SR800, and I have one problem I'm not too sure about. All the knobs on the thing work and sound great with the exception of the treble knob. Everything on the treble sounds good, but as soon as I reach 9 or 10 on it, it makes a constant hissing sound. It's not anything super loud, but more like some minor static. It's all good if I keep it at 8 or below, but as soon as I hit 9 that static comes up. It's an active bass, so I know there's the chance that it might be the battery, but it doesn't do it with any other knob but the treble, so I don't think it's that. The guy I bought it from said it probably just needed some contact cleaner or something of the sort, but I thought I'd ask the pros for their opinions before I did anything.