Thursday, December 9, 2010

Tone Switch in Gretsch Style

In this post I will show you my idea for a Gretsch style guitar tone switch. It's a three position (cap1 - off - cap2) low-pass filter selector. It can be a very useful tool, if it's well tuned.
In my circuit, I'm using different capacitors values than Gretsch. I'm also using a SPDT on-off-on toggle switch, which is easy to buy and comfortable in mounting.

The lower value tone cap will help you in getting fat overdrive tones.
The higher value capacitor is good for clean, really smooth sound.

I've got three version of this wiring. One is for classic Filtertron pickups (Gretsch, TV Jones). Second is for use with Fender style single-coils.  Third is for PAF style humbuckers and P90's.


How it works?

The guitar signal can go from the pickup selector to the tone switch. When the toggle is in the center position, both capacitors are disconnected from the signal line. By moving the toggle up or down, you can choose one of capacitors. Selected cap will be working together with the pickup as a low-pass filter. It will be cutting out portions of treble, from the main signal line to ground. Higher cap value means less treble in the guitar signal.

About tone

Low value cap:

This capacitor will cut off only really high frequencies. There will be higher cut-off level than in the original version (22nF).
It sounds pretty good with some overdrive. It will give you a fat and still quite distinct tone.
For my taste, it's not so good for a clean sounds - the tone can become a little bit dull and muddy.

High value cap:

The second cap has got higher value than the original one (47nF). It will cut off a lot of high frequencies from the pickup signal. It will make your clean tone very smooth, soft, with significant bass. It will not be so muddy like the original version.

BTW, why the original value cap will cut off less of high frequencies, but the guitar sound will be more dull/muddy?
Dullness or muddiness comes not from bass without higher frequencies. It's not „bass - (middle + treble)”. A dull tone is a signal with a lot of bass with middle frequencies also, but with huge lack of treble.

Tone potentiometer vs tone switch:

A tone pot can give you good control over interference of the capacitor in the signal line. Resistance of this potentiometer makes a wiring a little bit „smoother” - less treble can pass. It can't be controlled.

A tone switch will not affect your tone like a pot. All impact can be switched off/on, but you don't have this precise control over the filter, like with the pot. This is why it's good to experiment with capacitors values.


Remember, that in many Gretsch guitars, the tone switch is placed after the pickup's volume control. Using the vol. ctrl will affect work of the tone filter.

I hope, that this article will be helpful for you, if you are thinking about a new tone switch, or if you want to modify your original Gretsch guitar.

BTW, > here < is the post about a one-cap tone switch, and about using it in few, different electric guitar types.