tonyguitargoat

Hi, I've just bought a Bass Collection bass (SB 320 I think) with an active circuit. The balance control has a centre notched position, but it's only right at one end of the pot's travel that the neck pickup seems to mix in. I've cleaned the pot but no luck. Anyone know anything about this circuit? There is a tiny preset in there, but wondered if anyone had any ideas before I start tweaking it... Thanks.