This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.

Tuesday, April 17, 2018

CultureJam Shoot the Moon

Here's a great optical tremolo designed by CultureJam. Schematic can be found here. D1 is the external rate indicator and could be used as the on/off indicator as well. Just use part one pole of your 3PDT to break/connect one of the leads of D1. D2 and the LDR should be isolated together (heat shrink tubing works great). Tayda LDRs and either orange or red LEDs seem to work well in this circuit. A NSL32-SR3 optocoupler works well too. 


  1. are the two 220k resistors at the start of the LFO not redundant? You could just connect it to Vr from the power section (the two 100k resistors) or am I wrong?

    1. You're not wrong, but doing so would most likely introduce tick from the LFO into the audio signal. I can't think of an IC-based LFO I've seen that doesn't do this.

  2. good morning everyone, I'm new.
    I have a problem with this project: it works fine for a few minutes then starts to distort and then does not produce any more sound.
    I tried to change all the capacitors and both the ICs. same result.
    any suggestions?
    thanks, Stefano.

    sorry for the english i used the google translator.

  3. Hello to all.
    I solved with a delicate cleaning of the pcb. Probable some small short circuit.
    Now my problem is gain. Simply too much. I have to keep the potentiometer at most at 8 o'clock.
    It's normal?
    Thanks, Stefano.

  4. Just finished this build on the weekend. Everything functions as it should.

    I did have some issues where the LFO was not functioning and the wave control had no effect. I thought the 4558 chip I was using was dead (I pulled it from an old Peavey amp) but it turns out I had a small solder bridge that I didn't see initially.

  5. Just finished it, took 8 hours from etching the PCB to casing it. The Korg SV-1 has an onbeard tremolo, but it doesn't sound right to my ears. It's such a sweet little thing. It was one of those smooth builds. Unlike Valve Wizard's Engineer's Thumb . That circuit drove me nuts. It's still harassing me. I think I has to etch it again one of these days.
    Thank you for the time and love you put in these.
    You're a legend

  6. Does someone know a replace for the 5817 diode?

    1. You can use something like a 1N4001, it'll just drop the voltage a tiny bit more than the 1N5817

  7. Hi! Does anyone have any specifications for the LDR and its attached LED? Also, any replacement ideas for the JRC4558 would be much appreciated.