Wiring Assistance Please

impmann

I'm building an unusual guitar that will have two humbucking pickups - that each are split in two so that effectively there is a humbucker under the bass strings and another under the unwound strings. So think of it as four separate pickups.

I want to have four individual volume controls (one for each pickup output) feeding into a master volume control and a master tone control.

What I don't want is the Gibson thing whereby you turn down one pickup and the other is silenced when the control is at zero.

Therefore... I came up with the below rough schematic (based on just one pickup, the idea being I can double it up for the other) - will this work the way I want it to? Or am I missing something?

 

ICBM

It will work, but you’re much better wiring the master volume the normal way with the rotor to the output, otherwise it will be noisy when the MV is turned down. I also prefer to connect the tone control to the pickup side of the MV, not the jack side. (I know the jack side is ‘50s’ wiring on Gibsons.)

Also bear in mind that there are three volume controls in parallel so the total load will be a third of the resistance of any one. You may want to increase the pickup volumes to 1M.

impmann

Thanks chap.

Actually, thats my bad on on the MV - I meant it to be the 'correct' way around. My bad drawing! Yes, you are probably right about the tone wiring...

As for the pot values - the pickup builder (Kent Armstrong) recommended 250K pots but that was using the pickups in a slightly different configuration (as a Stereo guitar). I have 250k pots (push pulls - as I'm also having series parallel on each individual volume/pickup) - you think they may be a touch dark, then?   

ICBM

Three 250Ks in parallel will give a total of only 83K, which is going to be quite dull. Or you could put the pickup halves - and hence the volume pots - in series...

impmann

ICBM said:

Three 250Ks in parallel will give a total of only 83K, which is going to be quite dull. Or you could put the pickup halves - and hence the volume pots - in series...

OK, I *think* I follow - but surely that would make for a very high output too... and how could you wire that, meaning that when volume pot 1 is all the way down it doesn't turn the whole guitar off?

Bear in mind there will be four pots (one for each 'pickup'), plus a master volume - I am also considering this circuit instead of a straightforward tone control:

http://www.1728.org/guitar14.htm

ICBM

If there are four individual volumes plus a master it’s even worse - the total load with them all in parallel is only 50K. I think you will need to either increase the values, have some of them in series or use an active buffer...