Help Me With My Circuit

[hessodreamy]

A while ago I decided to make my cheap rickenbacker copy into...STEREO...STEREO so I could send different pickups to different amps.

It all worked great until I changed pickups, and now it doesnt work as it should.

I put in a second output jack and a 3 way, 4 pole rotary switch, and here's what its supposed to do:

(Bear in mind that the pickups go to their volume pots before the switch.)

position 1:

Bridge pickup to pickup selector and also to the 2nd output jack

Middle pickup to output lug on selector and also to 2nd output jack

position 2:

Bridge pickup to 2nd output jack

Middle Pickup to output lug on selector

position 3:

Bridge pickup to pickup selector

Middle pickup to 2nd output jack

In all positions the neck pickup goes to the pickup selector.

*****new***********

Here's the circuit diagram:

What happens now is that, in position 1, the bridge pickup is always on, regardless of where the pickup selector is.

The only thing thats changed between working and not working is that the old pickups had only a 2 wires - a cold and hot - wheras the new ones have 4 wires and a ground, but i've only connected the new pickups in a normal series configuration.

So does anyone have any idea why this isnt working as it should anymore?

Edited August 10, 2005 by hessodreamy

[hessodreamy]

Would a proper circuit diagram help y'all figger it?

Could rustle one up, but thought it would be a bit compicated...

[MerlinTheWizard]

Would a proper circuit diagram help y'all figger it?

←

Sure would.

[hessodreamy]

Would a proper circuit diagram help y'all figger it?

←

Sure would.

←

There you go. Diagram put in original post. Apologies for the crudeness of it.

Cheers

[hessodreamy]

Surely someone must be able to help me.

I was banking on the smarts and sharp minds of such a fine bunch of techies. (flattery....flattery...)

[lovekraft]

There's nothing obvious wrong with your diagram (so far as I can tell). I suspect there's a wiring error somewhere.

[JohnH]

Heres my theory:

Position 1 is the one on the right side of the diagram? in which you want the pup selector to be able to select:

main jack:

neck or bridge or both, with middle always on

2nd jack:

bridge and middle

Is that right?

If so, looking at the diagram - The bridge would always be connected to main jack in this position, because it is also connected to the 2nd jack. The middle pup is connected to both jacks - hence the wiring for the middle pup provides another path for the bridge pup to the main jack - bypassing the selector switch, putting bridge always on in position 1.

Can I take another 'shot in the dark'? Your diagram looks very similar (in drawing style too) in several respects to those of Shergold guitars (I have one) - including the use of 100k pots for everything and 47nF caps - wired with 3 coonections to the tone pot with outer lugs from output to ground, instead of having only the cap connected to ground as in most other designs. That puts with all pups in use, 5x 100k resistances in parallel with the output, which may cut down significantly on your treble.

Also, with the way the volume pots are wired, if you have more than one activated, turning one volume down to a low setting will cut down the volume of the other pups too. For that reason, guitars with more than one volume pot often put the wiper on the pup side rather than the output side.

These last too points I raise in case they are an issue for you, although not realted to your question. If they are, the fix is to use 500k pots, with wiring adjusted as above.

regards

JOhn

[lovekraft]

John nailed it! The bridge pickup is "backwashing" through the middle pickup circuit. Good catch!

[hessodreamy]

dagnammit! I see it now.

What threw me off was that it was working before the pickup change, so was looking for something more complicated.

In hindsight it probably didnt work to start off with!

Thanks for the help guys!

Edited August 15, 2005 by hessodreamy