varitone, how do you wire these?

[shoulderpet]

Am interested in one of these but my electronics and soldering skills are limited, I am a bit of a wiring simpleton and I can't see how this would connect in a normal two control p bass, obviously this would replace the tone pot, has anyone fitted a varitone that can advise me as to how these are wired, thanks

[John Cribbin]

Google varitone schematic to see the circuit.

 

Normally it works with the tone control. There are various versions, but basically each position on the switch shows a different value capacitor in the circuit, providing a different tone response.

 

Gibson was keen on these back in the day on their semis. By all accounts more were removed by owners, than fitted as an upgrade. It wasn't a popular mod.

 

I used to have a Gibson 330 copy with a varitone, only two of the six positions sounded any good to my ears.

Edited March 19, 2022 by John Cribbin

[itu]

Red one to signal, black to ground. Remove the tone pot. 

 

The basic idea is that different resistors and capacitors direct certain part of the signal away from the output. As there are only two places possible (out and gnd) the highs go to gnd. The amount is dependent on the values of the components.

[shoulderpet]

18 minutes ago, itu said:

Red one to signal, black to ground. Remove the tone pot. 

 

The basic idea is that different resistors and capacitors direct certain part of the signal away from the output. As there are only two places possible (out and gnd) the highs go to gnd. The amount is dependent on the values of the components.

Thanks, so if I was to use the below diagram as a reference I am guessing the red wire takes the place of the short wire linking the volume pot to the tone (except in this case this would be linking the volume pot to the varitone) and then the black goes to the ground on the output jack?

[itu]

Well, there are two options:

- red to the hot output

- red to the pickup's hot wire (here it is white)

Both are practically the same, but you want to try, the change of one wire (red) is quick.

[Andyjr1515]

The original Gibson Varitone (like on the EB-3) was a complicated little thingy electronically.  I know because I built one from scratch (with a LOT of help from the clever folks round here   ).  Complicated and of dubious benefit for some of the switch settings (as @John Cribbin says above).

 

But - if you want to be able to simply switch to a number of different capacitor values 'on full' with a rotary switch like the one you picture, yes - reasonably easy and relatively useful.  There should be a few diagrams on Google.  I'll have a peep when I get a chance if you can't find one.

[Andyjr1515]

This is the general principle from the StomBoXed blog:

 

The feed from the volume pot goes to A and the varying value capacitors are switched through one at a time, all with a common earth

[Rich]

Is there much to be gained from retaining the tone pot and effectively using the varitone circuit in place of the usual 47/50nF tone capacitor? Also I've read in a few places that the inductor (as used on the original Gibbo circuit) is of no/minimal benefit if used with bass, is this the case? 

Edited March 31, 2022 by Rich

[Andyjr1515]

5 hours ago, Rich said:

Also I've read in a few places that the inductor (as used on the original Gibbo circuit) is of no/minimal benefit if used with bass, is this the case?

Well, they tend to be all pretty much different shades of mud - but yes, you can tell the difference with the different settings.

[BigRedX]

When I built my solid electric guitar I included a Varitone mostly because I was trying wring the maximum in tonal variety out of a single humbucking pickup. I found the Gibson style varitone (based on the one in the 345 guitar) was very effective thinning out excessive bottom end from an over-wound humbucking pickup. How useful it would be on a bass guitar would very much depend on the sort of sounds you are after.