Another big one! Here is the famous crybaby GCB-95 wah pedal. A lot of people have this one, therefore, even more people are looking to mod it. A simple google search delivers a wide array of mods that is enough to boggle the mind of anybody trying to choose which ones to do.
I'm not doing anything revolutionary here but I did some common mods that, in my opinion, sound great! Some resistor values are lowered to increase the gain going into the transistor, effectively increasing the gain of the circuit. This however gives a great sounding wah sound!
Here are some pics of the changes I did to the board:
There's a nice little picture of the PCB. There are some variations between the different years. I believe this is one of the most recent GCB-95's.
R5: Changing this will change the Q of the effect. The Q is the width of the bandpass filter. Lower resistance, more subtle wah sound. Higher resistance will give you a sharper more vocal wah.
-68k - (This is the one I choose)
R1: Increasing this will smooth out the transition between heel to toe. Sometimes the stock wah can transition quite rapidly and doesn't sound too good. This should smooth out that transition and increase the mids.Stock: 1.5k
-2.2k - (This is the one I choose)
-330ohm - (The one I choose)
Stock: 68k - (I stuck with this value because I found it had no huge difference with the 47k)
List of mods done on my wah:
- Resistor Stock Mod
- R5 33k 68k
- R1 1.5k 2.2k
- R9 390ohm 330ohm
- R15 68k 68k
Everybody has their own preference of wah pedal. I like the way mine turned out, but I encourage you try different values and find out what works well with your rig. In general, all of these mods increased the gain going into the transistors. You can definitely hear the difference, my wah sounds more vocal, louder, and more gainier.