Guitar tone control wiring -

musicalstash

Any ideas what the previous owner was trying to achieve with this wiring ?

Its a 2 pickup guitar with a single tone and volume with a 3 way switch  , the volume works as it should but the tone control doesn't seem to do anything . 

https://ibb.co/2591dp5

https://ibb.co/jG1089v

https://ibb.co/zVvbpz6

thanks

SteveRobinson

Progressive coil split on one pickup maybe?

We'd need to see where the other end of the grey cable goes.

Funkfingers

My guess is that the grey insulated wire will be connected to the output terminal of the selector switch.

The pot to the right only becomes a tone control with the addition of a capacitor to determine the cut-off frequency.

The bent back ground connection only makes sense if the pot was previously used in another circuit. One where the capacitor itself formed the link between the volume and tone pots. e.g. A Gibson-style four-pot control array.

SteveRobinson

If it were connected to the output surely it would act as a volume control?

Funkfingers

Indeed. Therefore, the grey insulated wire goes elsewhere. (Need to know where.)

Your variable coil split suggestion makes sense. It could be a failed attempt at a Blend pot or the Rickenbacker "mystery" fifth control. 

ICBM

I doubt it's a failed attempt at anything - the workmanship is quite neat and professional-looking. The only thing that a variable resistance connection to ground disappearing in the direction of the pickups can really be is a progressive coil split.

Are you certain it doesn't make that sort of difference? It might not actually be that obvious, depending on the type of pickups. One difference would be that hum/buzz increases when the pot is fully down.

musicalstash

Just had the wiring out and it looks like the grey wire runs to the earth on the 3 way switch.

The control doesn't seem to do anything, I have put it through a high gain amp and there no difference to the hum. The alpha pot is not original and is the tone control. 

Funkfingers

The grey insulation covers a red signal-carrying wire, surrounded by bare metal stranded screen. 

Presumably, at the selector switch end, the bare screen is permanently connected to a grounding point on the selector switch. To what is the red wire connected?

Come to think of it, what format is the selector switch? Gibson-style sprung leaf toggle, Fender-style lever type or one of those hateful Asian toggles with its innards inside a metal box?

musicalstash

Funkfingers said:

The grey insulation covers a red signal-carrying wire, surrounded by bare metal stranded screen. 

Presumably, at the selector switch end, the bare screen is permanently connected to a grounding point on the selector switch. To what is the red wire connected?

Come to think of it, what format is the selector switch? Gibson-style sprung leaf toggle, Fender-style lever type or one of those hateful Asian toggles with its innards inside a metal box?

Just to confirm both the red and earth merge within the  grey wire and connect to the earth of the 3 way switch, it's an evh guitar so   guessing that the previous just  disconnected it or tried to bypass the tone control .

Trying to put it back to stock and found the original diagram but cannot make out what rating it should be  . Also the any ideas 8n the brand of the 500k pot, I thought it would be a cts pot but the only markings are on the side. 

https://ibb.co/cTdHt9j
https://ibb.co/mCnrzWn

Funkfingers

WD = WD Music, a purveyor of guitar parts. The commission pots with custom resistance tapers but don't always state what "custom" about them. 

Common values include 250, 500 and 1000. 

•

In the Peavey Wolfgang schematic circuit diagram, the signal arrives at the centre terminal of the tone pot. That portion of your existing wiring is correct.

In order for the control to work properly, you need to desolder the third terminal from the pot chassis and carefully bend it back to its original position. Next, use a .022 or .047uF capacitor to link the straightened terminal and the pot chassis.

The final step is to correct whatever is amiss with the selector switch wiring. It will be necessary to see photographs of the switch in order to suggest how to fix it.

musicalstash

Funkfingers said:

WD = WD Music, a purveyor of guitar parts. The commission pots with custom resistance tapers but don't always state what "custom" about them. 

Common values include 250, 500 and 1000. 

•

In the Peavey Wolfgang schematic circuit diagram, the signal arrives at the centre terminal of the tone pot. That portion of your existing wiring is correct.

In order for the control to work properly, you need to desolder the third terminal from the pot chassis and carefully bend it back to its original position. Next, use a .022 or .047uF capacitor to link the straightened terminal and the pot chassis.

The final step is to correct whatever is amiss with the selector switch wiring. It will be necessary to see photographs of the switch in order to suggest how to fix it.

Thanks all wired now  but in need of a capacitor. Found this in my spares, would it do the job?  

Its rated 0.022uf 400v. 


https://ibb.co/TKjLWNw

Funkfingers

Yes.