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 7, 2016

Parasit Studio Stepping Stone Overdrive

Here's an early design from Freppo from Parasit Studio. It's a punky overdrive/distortion transistor-based circuit. Here's the schematic for reference.

This was my first attempt at making my own overdrive from what I had learnt by building and modding other circuits. I had done a few heavily modded ones before, but nothing really original. I spent countless hours trying out different ideas on the breadboard before I was satisfied with the result. However, going back listening to this one now I find it alittle too thin/midrangy sounding, so I will probably revisit the circuit and improve it some time in the future.


  1. Nice!! I'll check it out over the weekend, please please could you upload the Parasit Phaser layout?!!?

  2. Sorry I dont know how to PM you directly so I've sort of hi-jacked this post.

    As a big fan of this site (I've built over 20 boards from here - some multiple times) I wanted to ask for your advise / critique / anything helpful really concerning my attempts at laying out the infamous and hated Boss MT-2 Metal Zone.

    Theres a post here:

    If you are too busy then no worries and keep up the great work!


  3. Nice sound, Parasit do some cool shit. I've been meaning to buy one of the PCBs for a while now.


  4. I would appreciate if you could design a layout for the arcadiator, I love that effect, regards!

  5. Verified.

    The OD is decently responsive to picking dynamics and the guitar's volume level. It works well for edgy, cutting chords, but like Fredrik says, it's a bit too thin. The sample clip gives a good idea of the sound.

  6. I experimented a bit more and found that the 220nF cap bypassing the JFET's source resistor seems to be acting as a bright boost. The Run Off Groove Azabache has a similar cap on a switch. If you leave the cap out, you will get a sound that is still thin but more balanced. Alternatively, you could try a larger cap to increase the frequency range of the boost.

    I also found that you can use a regular high-gain BJT in place of the Darlington for a less fizzy sound without a noticeable sacrifice in gain.