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, November 7, 2019

Keeley Mag Echo

Here's Keeley's PT2399-based delay that aims to emulate old tape delays. I think it's the first delay on the blog with built in modulation. It's laid out with board mounted pots for a 125B enclosure with top mounted jacks. FYI, the trimmer controls the gain of the input stage.




52 comments:

  1. I've been looking forward to this one! Now I just have to find time to put it together...

    ReplyDelete
  2. Thank you very much!
    But this is not the first delay with built-in modulation, the Deluxe Pitch Pirate has modulation also, or am I mistaken?

    ReplyDelete
  3. tiempo 1 se debe conectar en pin 6 de PT2399 y no en el pin 5

    ReplyDelete
    Replies
    1. David... I think Paolo is correct:
      "Time 1 must be connected on pin 6 of PT2399 and not on pin 5"

      Gracias, Paolo.

      Delete
  4. Replies
    1. https://www.pedalpcb.com/docs/MagnetronDelay.pdf

      That was the reference from the vero blog that presented this initially.

      Delete
  5. opa2134? thats overkill!! put a TL072!

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
  6. It works! I switched time 1 from pin 5 to 6 and it sounds great.

    ReplyDelete
    Replies
    1. Can you make the video .. sample to me sory my english bad

      Delete
    2. I don't really have a setup for that, sorry.

      Delete
  7. Has the pin in the layout been corrected?

    ReplyDelete
    Replies
    1. This comment has been removed by the author.

      Delete
    2. is possible make?? http://www.freestompboxes.org/viewtopic.php?f=7&t=20607&p=277360&hilit=schaffer#p277360

      Delete
    3. That's a good one, Miguel!
      https://aionelectronics.com/blog/tracing-journal-solodallas-storm/

      Delete
    4. Yes... this is more information and photos of the circuit tracing for that same pedal. Aion sells a PCB for it and you can download the schematic and build info. I found the link in the FSB thread that you posted.

      Delete
  8. Will work fine if replace Opa2134 to TL 072??? Thanks

    ReplyDelete
  9. @Effects Layout, 78L05 for 7805? Will it work fine? All 2399 builds I made were okay with the L05 though. Just want confirm, if you've tried it or anyone has.

    ReplyDelete
  10. Hi, as I suppose, I can replace 1N5817 with 1N4001/4007, right? Or even put a jumper instead?

    ReplyDelete
  11. There is a difference between lm358 and lm358n? can i use the first one?

    ReplyDelete
  12. As far as I know, the N-letter is just a packaging symbol. There's also P version but they can be used interchangeably.

    ReplyDelete
  13. Ive built this pedal completely but i get no sound even when on bypass (checked continuity between joints and its good) but the pedal just gives off high pitched squeel, any idea where to start?

    ReplyDelete
  14. Quizás debes girar el trimbots.... Hay alguna otra modificación para este pedal? Han encontrado alguna falla?

    ReplyDelete
  15. what is the size of the circuit? to print it on the sheet

    ReplyDelete
  16. Ive finally gotten it working, I replaced the extremely large capacitors with ones recommended by the pt2399s manufacturers. The size difference is so large I'm not sure how it ever worked.

    ReplyDelete
    Replies
    1. Hi Justin, can You provide the values of the caps to change and the new ones, please?

      Delete
  17. This comment has been removed by the author.

    ReplyDelete
  18. This comment has been removed by the author.

    ReplyDelete
  19. Hi, built it, works, all pots work, except feedback pot - I just don’t feel the difference when adjusting, can You please tell me what could be the reason?

    ReplyDelete
  20. Hi! Just finished building this, now i have 2 questions:
    1. How shuold i adjust 100k thimpot?
    2. Delay works, but i cant hear modulation (the rate led works when the depth pot is more then 0, but doesnt dim completely). Where should i look?

    ReplyDelete
    Replies
    1. Got it working! I missed a small soldering bridge just near time pot.

      Great delay!

      Delete
  21. I have the same problem. The delay works but the modulation does not. No chorus sound. I have already reviewed the entire circuit but I have not been able to resolve it yet. Or is the modulation sound really discreet?

    ReplyDelete
  22. Works!! Great sound! Thanks

    ReplyDelete
  23. Done and working perfectly. Thank you very much for the layout. The way I'm going to use it, I don't need the Rate led (removing it does not alter the operation) and decided to replace the Speed potentiometer with an internal trimpot. I also changed the 100k log potentiometer for a linear one (I need more precision in the first section of the round).

    ReplyDelete
    Replies
    1. hi, did you have to make any modifications to make it work perfectly?

      Delete
  24. This comment has been removed by the author.

    ReplyDelete

  25. I built the circuit and it is working, but there is background noise, is it normal?

    ReplyDelete
  26. Hello, did anyone test it on a bass? On the guitar it sounds perfect. But with the bass it saturates and distorts a bit.

    ReplyDelete
  27. hi everyone,
    Does the 7805 need a heatsink ?

    ReplyDelete
  28. I've built this circuit but minw has a slight volume drop. Does the trimpot adjust the output?

    ReplyDelete
  29. I succeeded thanks to your website.

    ReplyDelete
  30. Curious how to mod it so you can get the modulation on the dry signal (do becomes a chorus pedal). Add a switch off depth 2 and send it to OPA pin6?

    ReplyDelete
  31. This comment has been removed by the author.

    ReplyDelete