Model 4 pickup questions

[gitfiddler]

Hello. i bought an '86 model 4 with stock pickups. I plugged the guitar in when i got it and there was no sound. i put in a new battery, and ta-da.. sound. Only the volume knob works though. The second and third knobs do nothing. My understanding is that the second knob is a tone knob (which i'll never use anyway), but what does the third knob do? I'm getting sound, but the knob doesn't do anything.. is there a chance that, soundwise, it's fully "on?"

i took it to a shop today to get a setup, and the guy said if the preamp is blown, i'm out of luck unless i can find a replacement. Is the battery just driving the preamp or is it driving all pickups and the preamp? I've only ever had passive pickups and am not sure how it works



thank you

[ZZB]

Those are passive pickups in your Model 4, and I believe the knobs are vol-tone-midboost. The third knob is for controlling the JE-1200 active circuit, if it has no effect on the sound it would seem the preamp is indeed busted.

[richardlawson]

I thought model 4's had active pickups. Otherwise why else would a battery make the pickups work?

[Alvin_Wilson]

I thought model 4's had active pickups. Otherwise why else would a battery make the pickups work?

Jackson/Charvel did not produce any active pickups, only active circuits that boosted their passive pickups. The battery is for the active midboost circuit.

[gitfiddler]

why did the guitar have no sound when the battery was dead? I'd think that if they were passive pickups and the battery was dead, only the boost wouldn't work ??

[Alvin_Wilson]

why did the guitar have no sound when the battery was dead? I'd think that if they were passive pickups and the battery was dead, only the boost wouldn't work ??

I'm not sure, but I would guess it is because the pickups are wired to the circuit, which requires the 9v battery to function. The pickups will work, sans the circuit, but will have a weak output. btw, I sent you a PM.

[charvel750]

Alvin's right. Even though the pickups are passive they are wired into the circuit so without battery power the output is shot. Carvin wired some of their active circuits so that you could switch back and forth, wouldn't be a bad idea in case of a dead battery...