Tone knob wah

mistercharlie

Is it possible to do something to the tone knob on a strat to turn it into a wah?

I almost never use the tone control, so I thought having a wah in there might be handy, for dialing in cocked-way sounds. 

Funkfingers

It is possible to achieve wah like results by dexterous use of the little finger to rotate a passive treble roll-off control. (I associate this technique with old/dead guitar legends such as Speedy West and Roy Buchanan. Younger readers, find any Greg Koch YouTube video demonstration of his signature Fishman pickups.)


A conventional wah pedal effect relies on an inductor and a supply of power. 

The Eldred "cocked wah sound" modification for Fender Esquire involves a passive network of capacitors and resistors. It should be possible to have variable notch filtering via one or other of the lower two pots of a Stratocaster.

Your opening post refers to THE tone control on a Strat. I am wondering on what sort of Stratocaster-derived guitar do you propose to perform this modification?


My inclination would be to make this capability available to all of my guitars by having it in a pedal.

mistercharlie

Funkfingers said:

A conventional wah pedal effect relies on an inductor and a supply of power. 

The Eldred "cocked wah sound" modification for Fender Esquire involves a passive network of capacitors and resistors. It should be possible to have variable notch filtering via one or other of the lower two pots of a Stratocaster.

Nice. I’ll take a look at the Eldred mod.

Your opening post refers to THE tone control on a Strat. I am wondering on what sort of Stratocaster-derived guitar do you propose to perform this modification?

It’s a Strat, but the second (bridge) tone knob is already performing as a bass-cut knob, which is just about the most useful mod I’ve come across.

My inclination would be to make this capability available to all of my guitars by having it in a pedal.

I have a Cock Fight, but I thought it might be a handy mod to the guitar.

PhilKing

Chandler used to make a control called the Tone-X which was a wah on a pot for your guitar.  You needed a battery, but other than that, it was a wah on a pot.  I used to have a couple but took them out years ago as I realized that having the pedal made it easier to find the sweet spot.

Funkfingers

The EMG-VMC accessory could be adapted to work as a wah. 

So, if you can find one, would the fabled Seymour Duncan Tone Circuits Parametric Midrange Prototype. (As used by Frank Zappa.)

In both instances, one half of the stacked knob selects the centre frequency whilst the other governs the cut/boost.

xscaramanga

The 1997 Joe Perry signature Les Paul has a wah on the neck tone pot, powered by a 9v battery.

(I've got one for sale.)

clarkefan

Didn't Danny Gatton do something like this, using a 1meg pot?

mistercharlie

I’m giving up on this plan, due to it being far too involved, plus there’s no space for a battery in the guitar.

I was hoping for some clever circuit that would use just capacitors and resistors to allow me to dial in a nice narrow resonant peak wah. With all this work, I’ll stick to a cocked wah pedal. 

Thanks for all all the suggestions though. 

ICBM

mistercharlie said:

I was hoping for some clever circuit that would use just capacitors and resistors to allow me to dial in a nice narrow resonant peak wah.

Unfortunately it can’t be done with passive components alone - either the band is too wide, or the roll-off is too shallow, or there’s too much insertion loss... or all three.

Matt_McG

Some people seem to be able to get uncanny tone effects using just a passive tone control:



Things like the Tonestyler use an inductor, but those are stepped.

ICBM

Matt_McG said:

Some people seem to be able to get uncanny tone effects using just a passive tone control:

Certainly, but it's not the same as a narrow bandpass resonant filter.

If you do want a 'hand wah' on the guitar, actually a high-value *linear* pot works well - contrary to what you want for a normal tone control - because it gives all the sweep over a short part of the turn at the bottom end.