Hello
I’m experiencing a rather strange behaviour with an old Shin-Ei Wah Fuzz i am servicing : The fuzz works fine, but the wah is verrrrry silent.
I didn’t know if the low volume (nearly silent) of the wah was caused by a faulty 2PDT (the unit features one switch for the fuzz effect, and one switch for the wah effect, and was covered by dust and dirt), a faulty wah pot, or a faulty component on the PCB. I made some investigations, so here is the situation :
- I unsoldered and rewired all the wires from the original 2PDT to a brand new 2DPT, the « silent wah » issue was still here (so i could tell that the old 2pdt is not the culprit).
- In order to make some tests, i then made different wirings on the wah’s 2PDT. With one of the wiring, i could get a decent volume out of the wah, and i could hear that the « wah pot » works fine, so it’s not the cause either.
- I investigated further, thinking that it might be a faulty transistor or an ageing capacitor… I changed again the 2PDT wiring : there, i managed to get both the fuzz and the wah working altogether at a decent volume… So, it seems that the silent wah issue is not a faulty component on the PCB (at least to my small knowledge), but i suspect it to be related to the wiring between the PCB, the wah 2PDT, the Fuzz 2PDT and the jacks… Could it be that, depending on both 2pdt position, the sound goes to the ground instead of going to the output ?
I am going to make wiring schematics and more detailled informations about the wiring i did, i will post it a bit later today.