Hijack Your Wah Pedal
Using a GCB-95 CryBaby Wah Pedal

This is a simple modification you can perform to your CryBaby wah pedal (and your guitar) to allow you to use one of your guitar pots to 'wah' the sound. I find I can incorporate the wah effect into my guitar playing technique, and I dont need to use my feet. After all, the guitar was made for the hands, not the feet. The Stratocaster guitar (or Strat copy) is a perfect candidate for this project because there are easily reachable controls and because the Strat has 2 tone controls. Most find this unneccessary, as only one master tone will suffice. The fact that the Strat sounds great through a wah is also a great feature, it seems the guitar is a perfect candidate for the wah effect. Do you agree Jimi?

This mod has some pretty neat advantages. I've listed them:

Of course there are the cons:

The first con is the battery switching on the wah. The CryBaby wah has a feature which allows the battery power to be cut when the guitar input chord is pulled out of the input jack. This saves power when the wah is not in use. There is a stero jack in the wah that connects battery negative to ground by using the 'ring' terminal on the jack. Good feature. You can't have everything, but it's easy to work around. Here are your options:

The mod requires work on the wah and the guitar, but is pretty straight forward. Let's tackle the wah mod. Here you only have to switch two wires in the Crybaby Wah pedal. First wire: the black wire from the main pot. This wire connected at the main pot can also be found by testing the resistance to ground. With the wah pedal up the resistance should be pretty much zero ohms. Second wire: the black lead from the battery. You can switch these two wires at the top of the connector that plugs into the circuit board by carefully pulling out the wires and swapping them. The connector has 8 pins. If you are looking at the connector and the main pot is on top, the input jack on the left, count pins from the left. It is the first and third pin. You can also cut and twist the wires if you want to leave the connector alone. Maybe use a small marret or some electrical tape. You can use an spst switch to disconnect battery power instead of disconnecting the battery, on either the positive or negative lead coming from the battery. I just disconnect the battery myself, but another option is to use external power.

Next is the guitar. You'll need to remove the pickguard and input jack. Install a 1/4" stereo jack in the guitar and add a wire from the 'ring' or middle terminal of the stereo jack to inside the pot area. Leave the 'tip' and 'sleeve' the same (resolder). There are now some options. Guitar pots are usually 250k or 500k, audio taper or linear taper. Any pot will work, but will work a bit differently. So there are 4 pots basically, 250k linear, 250k aud, 500k linear, 500k audio. Start by desoldering the wires to the pot you want to use as the wah pot. If you are hijacking a tone control, remove the capacitor lead that connects to the pot lug, if it isn't the lug you plan on grounding. Solder the wire from the 'ring' or middle terminal of the guitar input jack to the center lug of the pot you designate for the wah effect (The pot has three terminals or lugs). There are now three ways to wire the pot:

  1. Ground the left lug
  2. Ground the right lug
  3. Ground both outside lugs

If you only ground the left or the right lug, you will only be able to wah going either ccw or cw direction, near the end of the pot movement. If you ground both, you will be able to wah going either full ccw or full cw direction. Kinda handy. Here's the thing: depending on which pot value you are using, and how you ground the outside lugs, the wah effect will change. This mod does not duplicate the wah effect electrically, but is very good. I find it's good enough.

I ground the lugs of the pot by soldering them to the case of the pot. The pot case is then grounded by another wire and also by the aluminum tape on the backside of the pickguard. By trying different methods, and different pots, you can find what you like but again all combinations listed will work. The audio taper or other non-linear taper pots will be more or less sensitive at either cw or ccw depending on which outside lug is grounded, even when both outside lugs are grounded (see chart). You might like this, again there are three different ways to wire a pot here, and you can always try a different pot entirely. I use a different pot, a 1 Megaohm linear taper pot grounded at both ends. I find the 250k pots don't have enough wah to them, unless you ground only 1 end lug of the pot.

Direction of
Knob Rotation for
Pedal Down Effect
Grounded Lug
full cw left
full ccw right
full cw or full ccw left and right

If you are using an audio taper pot, or other non-linear taper pot (besides a weird reverse log), the wah effect is more sensitive near the cw direction; you require less knob rotation for the wah. The wah is always full (pedal down) when the pot is at the stop, either cw, ccw or both depending on which lug(s) is grounded. You'll just have to experiment. The audio taper pot with both lugs grounded will have the 'pedal up' off-center. The linear taper pot is balanced so if you ground both left and right lugs, you will be able to create the 'pedal down' effect evenly with either cw or ccw knob rotation. 'Pedal up' will be at the knob center, or number 5. You will find that 'pedal up' actually happens before the knob is centered, but even in both directions.

Remember: Use a stereo chord! Get a decent quality shielded stereo instrument chord with 1/4" stereo plugs at the ends. You will only be able to wah with the guitar pot WHEN THE FOOT PEDAL IS DOWN! If you turn the pot on the guitar all the way to where you get the pedal down effect (cw, ccw or either), you will be able to use the foot pedal to wah. If you use a mono guitar plug, the wah will work with the foot pedal, and the guitar will also work as it normally would, without the use of the new on-board wah control of course.

So what to do with the wire from the middle pot tone control you disconnected? If it's a strat, you can leave it off and you can also take the other tone control and remove the wire to the five-way switch and solder it to the left volume pot lug. This will give you a 'master tone control'. I don't use a tone control anyway, I prefer to wire my Strat with my own method. See my strat wiring mod here.



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