Ok... a couple days ago I received a broken wah a friend gave me. the circuit seems to be fine, there is no brand on the wah. on bypass everything is ok, but when I engage the pedal, I hear a nasal tone on the guitar, but when I rotate the pot, nothing happens. I made a schem from the board itself, it took me hours but it is done. sorry for the messy schem. can you help me to debug it or identifiying the circuit? Thanks in advance
(https://dl.dropbox.com/u/27080694/wah%20schem.png)
It all looks like a standard wah crybaby etc, with an error. The 1.5k from base q1 to inductor should hook up at bottom of inductor they way you have it drawn, rather than go through the 33k. The 33k would normally be parallel the inductor. If your actual wah is wired this way, it might cause the prob you are experiencing. Compare the schem you drew to a regular crybaby schem and you will see what i mean.
thanks! but I am kinda rusted on electronics, can you make a corrected schem of that part in especific? I gonna look a std wah to compare anyways
you are capable of doing a comparison, i have faith in you!
Ok I will, I'll post my results! I have several months w/o playing with electronics, but i will! :icon_lol:
Ok, I found it, it seems that the PCB is factory defective because there are no bridged solder or anything like that, somewhere in my room I have Tonepad wah wah PCB with some components removed. I gonna remove ell the components of that wah circuit and putting them into the tonepad PCB. hope that works... at least the most important thing are there: the inductor (a very difficult [if not impossible] piece to find in my country [El Salvador]) and the potentiometer (again, in El Salvador all you can get are linear pots)
I'm bumping my thread! ok I made the new PCB and recycled the components. but I'm having an issue: the wah pedal makes random noises and crackles, and worsen if I move the pot. I thought it was the pot, removed the pot but same random crackles, I checked for microphonic (mixed ceramic and film) capacitors (because I had the same problem on an mxr dist+) and bad soldering... everything seems to be fine... can somebody help me? Should I change all the caps and transistors, or it is something else?