Friday, 6 July 2018

GTC Bloody Finger

Original PCB and Schematic available on the PedalPCB website here.
Review and info available here.


  1. Hell yeah! Thanks man. I'm cutting tracks and putting links in right now .I'll let you know when I get it working. Appreciate the effort sir

  2. Side note if anyone managed to get the 1k:8r radio shack audio transformers they are a sub for the tm013. Also there are a ton on eBay

  3. Check the schematic, it is actually a crybaby into a CMOS distortion, the "Tone" pot is the wah's pot. The only difference is the resistor in series with the inductor (the transformer's secondary winding in this case), which is 330k here while 33k in the CryBaby. In the CryBaby it is a common mod to change its value to change the Q of the filter. Often a pot is used, could be a mod here too. Or maybe its value is changed to follow the different inductance of the inductor here. I don't know the inductance of the 42TM013, but I guess it is somewhere around 500mH. I'll try to measure it if I can find one.

  4. Yes, Csaba... the 42TM013 has a primary winding that measures 500mH. You mentioned secondary rather than primary, but otherwise you have the right idea. Smallbear Electronics sells those transformers as a cheap alternative to buying a wah inductor. An inductor would do fine. I have a couple that I swapped out from other wah pedals, so I will probably build this pedal using one of those.

    Looks like fun. Thanks Alex!

  5. Tag it, not as strong a sweep as I expected, maybe the transformer instead of a actual inductor. Like Wad above I'm gonna use a wah reclaimation L and see if it makes a difference

  6. A Red Llama with a CryBaby in a small enclosure?

  7. Does anyone know where to put a gain pot on this circuit? I'm thinking maybe replace a resistor for a potentiometer but wich resistor would it be? This would be just for turning the gain down some if possible?

    1. An easy way, put a volume pot in the input of the circuit, this way you can control the gain same as the volume knob of your guitar. Not the best, but can work.

  8. Just finished this one tonight, it worked the first time I powered it up!
    Such rich sustain!
    Strummed chords sound great, each string rings out, no mud!
    I think this is going to be my new favorite pedal!