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.

Monday, November 16, 2015

Seamoon Funk Machine

The Funk Machine is a filter effect that can be used on either bass or guitar (or synth, Rhodes, harmonica, etc). It's also like an auto wah, given that the wah effect is controlled by the string attack of the player. Original units used 2, LM741 chips, but I've laid it out for an LM1458 (which is 2, 741 in a dual op amp). Don't try to use a TL072 or JRC4558, as they will not work in the circuit. Check out the discussion of this circuit over on Tagboard Effects for more info.


  1. GooD Job man !
    i am verified this circuit ...but substitute the resistor 2k2 for 2m2 !!!
    atent this detail !!!

  2. i second that ^ 2k2 should be a 2m2 based on the tagboard layout

  3. Anyone have any issues building this?, I'm pretty sure I've got the layout correct and I'm using an MC1458 op amp and 2N5088 transistor, 2.2M resistor as noted above but I get no sound. There is clean sound on pin 2 of the op amp and a little sound on pin 7 but it is distorted and limited to only a short attack when picking hard. Any ideas?, I've checked component values , swapped op amp and transistor but no luck so far. Don't want this to beat me !

  4. After replacing the 2.2K Ohm resistor for 2.7Meg Ohm and the 100 Ohm one for 51 Ohm one (as per this thread on DIYStompboxes: the effect started to work properly.

  5. Where can I get the construction kit for Seamoon funk machine ?

  6. Verified.


    The 2.2k resistor absolutely needs to be changed to 2.2M
    I haven’t played around with the 100ohm but it can likely be changed for a 1k pot.

    1. How will the 1K potentiometer work at that point? What would regulate that? Greetings!

  7. lo probe y funciona, eso sino dude y lo construi con la resistencia de 2.2M y 52 ohm. Suena lindo, hay una segunda version. Tambien la voy a probar. Muchas gracias por los aportes. Saludos desde Argentina.