Three pickups... control options?

[slinkp]

You don't often see many basses with three pups.
I'm planning a custom bass with an odd mishmash of pickups
(a 76 Gibson T-bird for the mid position and a ZBS 440 for the bridge), and it was gonna be a two-pup bass but I have this Gibson EB4 pup lying here and I thought hmmm, that would be kinda fun to put in the neck position for when I want a deep dark retro sound. But I can't think of a good way to wire it up.

I have a U-Retro preamp I was going to use, but it's only designed for 2 pickups.

Easiest would probably be to rig up a 3-way selector switch before the preamp, so that I'm feeding in either the T-bird or the EB4 or both to one input on the preamp, and the preamp's blend control mixes that with the bridge pup?

Or maybe I could ditch the U-retro and go passive with 3 volume controls? Or go passive with a strat-style switch?

Balancing the pups seems likely to be problematic, since impedance and output varies wildly.
Would something like Bartolini's buffer circuit help?
e.g. the AGDB at
http://www.bartolini.net/information/electronics/electronics_a.htm


Any other ideas?

 

[A9X]

Rig it with two passive volume controls, just like on a normal passive bass and plug them into input 1. That way you have some volume balance/adjustment between the two pickups. Wire the third pickup into input 2.

There's a URetro forum on The Dudepit where you can check out and see if this will work fine in practice. Surely someone's done it before.

 

[slinkp]

good idea, i'll post there. That'll make 4 forums where I've posted this goofy idea

 

[dunamis]

Link Removed

 

[slinkp]

LOL, I guess pretending it's a Strat is one option! Thanks.

 

[Selta]

V/V/V/T that way you can go any pickup you want any vol, without switching or jacking. I wanted to do a J/P/J bass like this once... mayhaps some day I will..

Ray

 

[slinkp]

JPJ eh? This one looks interesting:

... But I haven't yet heard how it was wired up.

 

[John East]

What we did for the one in the pic was to have a passive blend between the J pickups and then the normal Retro blend between the P and the output of the passive blend. This gives you any blend combination.

I would normally up the input impedance of the input taking the blend to load it less too, as the Retro is normally designed to mimic the impedance equvialent to the VVT set-up, in order that J pickups retain their sound.

John

 

[slinkp]

Cool, thanks John!
Is that just a simple resistor change that I could do myself?
Which resistor(s) should I be looking at?

 

[John East]

It's simply snipping out one resistor as one item, but I best email some details to you as there's at least one other point.

John

 

[slinkp]

cool, you can email me at [email protected]