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.

Thursday, June 16, 2022

Greer Amps Soma 63 Preamp

Cool JFET preamp circuit from Greer. Its supposed to sound like a Brownface-era Fender amp. I'd be curious what it sounds like without the transformer. Should fit just fine in a 125B with top mounted jacks. Schematic for reference.




9 comments:

  1. By emma electronics https://www.freestompboxes.org/viewtopic.php?p=291206#p291206

    ReplyDelete
  2. Buen dia. en cuanto me llegue el transformer , les apoyare con verificar.

    ReplyDelete
  3. Good day. I already have the transformer, but I don't know the orientation of the pins. Could you tell me which one it is?

    ReplyDelete
    Replies
    1. Pin one is indicated by the square pad on the toner transfer (top left)

      Delete
  4. Ya lo construi. Me gustó su sonido. lo voy a incluir en mi cadena de efectos. Gracias David.

    ReplyDelete
  5. Built it, sounds fantastic (with some tweaking of the fet drain resistance..). Note that the perf backside layout is missing the ground connection for the q4 source after the 1k resistor...

    ReplyDelete