Bypassing preamp in a min jazz deluxe bass?

easlern

easlern

Boredom artist
Hi all- I got this used mim jazz deluxe and I love it, but it has a preamp and there's not a toggle for it. So I want to bypass the preamp completely.

I don't use volume or tone controls, they're always at 10. The only thing I want to keep is blend/pan between the two pickups. So my plan is to take the pickups to the existing blend pot and straight to the jack from there. Can anyone see any pitfalls there? Anybody done this kind of mod before?
 
If you had a meter you could measure. 12K sounds pretty hot for pickups, but if those numbers are correct, then it should work just fine the way you planned.
 
I'm curious if one of the knobs is a push-pull switch for active and passive modes. A lot of preamps have that option.
 
Ray: I did get a practice amp. :) But I'm really talking more amp sim. Either way, I got eq.

Chili: Nope, no push pull on this baby. :(

Anyway I did manage to do the mod tonight. Very different sound, there must have been some compression going on in that preamp because my dynamics now are all over the place. Not random, just much more varied and I'm having to add tons of compression. I play with a pick too so figure that one out. It's much warmer, a little mushier, lacking some of the attack the preamp gave it. And it's much more prone to picking up 60 cycle hum. Didn't have that problem before.

They say if I'm balanced between pups there should be no noise but I get most noise panned to the bridge pup and least noise panned to the neck. Not sure what's up with that. . .
 
Did you keep the bridge ground wire connected? Maybe with all the rerouting and soldering, you disconnected the bridge ground.
 
Nevermind, played with some settings in the daw and it sounds great! Just needed lots of compression and some tone shaping.
 
Hmm, you would think compression would bring out more noise, but glad you got it working.

If you ever have the mind to experiment with bass preamps, try the Aguilar preamps. They sound so nice.
 
Chili: my tester shows the ring of the cable and the bridge are connected. So that looks okay maybe? But when I test for a connection between ring and a screw on the bridge pickup I get not connected. The neck bridge pickup screw shows it is connected to ground though. I'm not sure if that's any indication of anything though, really. I'd have to pull up the pups to really test maybe.
 
Technically, the sleeve should be ground. But the ring should be connecting to the sleeve of your cable in this instance anyway...
 
Haha I'm a little behind you chili sorry. Yeah there's a bit of noise still but it's greatly reduced by moving to another part of the room. A lot like my dynamic mics so I'm thinking maybe it's not the guitar really.

I was kinda thinking of getting some nice pickups but I think I'm burned on preamps now. Full disclosure, the one I had went out on me, hence this project. :P I'll miss the noise cancelling (however that worked) but it sounds a bit richer in tone now, if I might hazard a judgement on first listen.

---------- Update ----------

Oh yeah you're right farview. Got my cable anatomy mixed up. . .
 
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