80’s Dunlop Crybaby hackery
I got a free 80’s Dunlop Crybaby today and I like the sound of it but… I want to turn it into a box pedal so I can leave it in a toe or heel position into my OpAmp Big Muff Pi. So while I have this thing open I might as well throw some more control/mods on it. Here is some random notes I found on it.
Transistor Notes:
- The 5117 silicon NPN transistors used in 70’s Crybaby wah pedals are not 2N5117’s. The number 5117 is a part number from Thomas Organ company. They are standard T092, e-c-b left to right on the flat side. Although they are obsolete, the modern day equivalent is 2N2925.
Sweep Notes:
- you can widen the sweep by increasing the sweep cap (.01 off q2 emitter/inductor). a little goes a long way, try adding .002 at a time in parallel while listening. you can lower the sweep some without altering the highs. generally, the higher the pot value, the more highs.
Misc:
- “Q” adjustment mod: changed 33K Ohms resistor to a 100K Ohm trimpot. You can use either a 56K or 68K resistor to tune the “Q”. Tuned trimpot to 56K ohms w/ multimeter before installing wah on circuit board.
- Gain/Bass mod: changed the 510 Ohms resistor to a 1K Ohm trimpot. I adjusted trimpot w/ multimeter to 330 Ohms. Recommended trimpot values would be between 270 to 330 Ohms. You can use regular resistors in the 270 to 330 Ohms range.
- Midrange mod: changed 1.5K Ohms resistor to 2.2K Ohms resistor. Other values to try out would be between 1.7K to 2.2K Ohm resistors. I was considering adding a 5K Ohm trimpot in place of the resistor and marking the trimpot on the values mentioned above. I might try this out in the future.
- Volume mod: changed from 68K resistor to 47K resistor
- Lower the wah frequency range: Changing the 0.01uF capacitor to a 0.022uF capacitor.
Mother of all info on wahs can be found here!