I have a four or so year old peavey b-ninety with what im pretty sure are the original pickups(i bought it used from someone). when i play my bass i get theis hiss or electronic rrrrrrrrrrrrr noise that drives me crazy. it is stronger when my hands arent touching the strings and weeker when they are. is this my pickups or is it my amp or am i just insane. and if it is what type should i replace them with (if its not them i stilll think four year old pickups have to be gettin worn out).