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.

Wednesday, May 18, 2016

Run Off Groove Big Daddy/Grace

Here are two great sounding, yet simple circuits from Run Off Groove. The Big Daddy uses a JFET gain stage to push a 386 chip, while the Grace uses a JFET buffer in front of the 386 for added sparkle. Schematics, sound clips, and more info can be found on the ROG site.


  1. As I can send you a message ??

  2. Bigdaddy is ok. Grace not so much. The 6.8nF capacitor in Grace must be connected to the source, not the drain, according to the schematic.

  3. Hi!

    Can i use 3.3 cap (50V) instead 2.2?
    Can i use 13k instead 15k resisitor?
    Can i use 4.8M-4.9M instead 4.7M resisitor?

    Its critical for sound?

    Thank you so much and have a good day.


  4. I don't understand the difference in sound between Big Daddy and Grace. I never listened them.

  5. I want to attach a daughter-board BMP Tone Stack or a Hi-cut filter on the Big Daddy. Where do I put In and Out from daughter-board (Toneboard) to the FX PCB? :)

    1. Easiest way is to wire the out of the Big Daddy to the input of the daughterboard.

  6. Ok thanx, what about out on daughterboard? Would that be the new output to 3pdt ?