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.




65 comments:

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

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  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?

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

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

      Gracias, Paolo.

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    1. https://www.pedalpcb.com/docs/MagnetronDelay.pdf

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

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

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

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  7. Has the pin in the layout been corrected?

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

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

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    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.

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

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  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.

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

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

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  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.

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  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?

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

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

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  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.

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

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  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?

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  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?

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

      Great delay!

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  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?

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  22. 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).

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

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

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

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  26. hi everyone,
    Does the 7805 need a heatsink ?

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

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    1. Mine too, is there any solution??

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    2. The trimmer adjusts the gain output (i think) lol kramtone?

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  28. I succeeded thanks to your website.

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  29. 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?

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  31. Build it, exelent pedal! Used A TL072 instead of the OPA2134.
    Thank you! replaced a 9.1K resistor instead of the 10K in the level control (after the 1uf on the middel lug of the level pot, to get slightly more echo level in the mix.

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  32. Is it possible to replace a 100k trimpot with a 500k?

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

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  34. I changed 10k resistor near 1uf cap level pot to 6k8 and wet signal raised up as i expected

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    1. edited : my dropped volume issue solved by increasing the only 15k to 80k - 100k, somehow my simple delay cave dweller 2022 nicer than this

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  35. Just finished it (perfboard), and I really like it. The rate LED is not very bright unless depth/speed are maxed so I used a bi-color LED for both rate and on/off indication.

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    1. Mine's not working well.
      (Speed,depth,fdbk) not working...i think i have a faulty 2399.
      And this LM358 pretty hard to find here.

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  36. Hi everyone...
    Is BA10358 the same as LM358?
    Thanks in advance

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  37. Hi friends I made this pedal and works fine but in the Time potentiometer when I put around 7 make a very heavy noise I don’t know what happen any suggestion? Many thanks

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    1. Dear friends I solucionated this problem changing the pot of B50k by one pot of B25k with this solution the noise is not existing. Many thanks.

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    2. but i lost 50% of control with this potentiometer, someone knows how take of this noisse with a potentiomether of 50K many thanks.

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