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, April 16, 2015

MXR DynaComp

Here's the classic DynaComp compressor from MXR. This frequently cloned and copied effect has been an industry standard since it was introduced in the 70s. It uses the CA3080 IC, which can be a bit expensive and/or difficult to source as it is a rather obsolete chip. It might be a good idea to use tantalum capacitors in the place of the 1µ electrolytic caps for noise purposes. You can mount the pots directly to the board using either long leg right angle PCB pots or these more normal ones.


29 comments:

  1. Verified! Any issues, for those who having a fuzzy sound, just find the right spot for the 2K trimpot.

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  2. Is there any drilling template for this one if I mount the pot on the board?

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    1. I haven't made one for this as it's only 2 pots. It also would depend on which type of pots you're using. The holes for the pots would 1.2 inches apart though.

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    2. Using cable to connect the pots would be the best option then. Thanks pal

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  3. is there way to convert another diode to become 1N5817 just like converting LM13700 to ca3080? could not find any in local store. all I have in hand is 1n5819.

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    1. That's just for polarity protection. The 1N5819 is extremely close to the 5817, so that'll work well. 1N4001 or 4148 will also work ok.

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    2. thanks pal, I'll try all of them.
      mind to check my comment on sea blue eq?

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  4. Dude, thank you very much!
    now it perfectly works!

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  5. is it possible to replace 2k trimmer with pot b2k?

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    Replies
    1. Yes, but making it an external control isn't worth it. If you can't find a 2k trimmer just uses 2, 1k resistors.

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  6. Buenas tardes, estoy en los últimos detalles de el armado de este pedal con su esquema, como seria la modificación de ser posible para agregarle un selector de control de ataque? Muchas Gracias, saludos!

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    1. I believe our buddy here was asking about mod of "Attack" knob, which appear in Mini Dyna Comp.
      Any idea?

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  7. Hi, firstly, as ever, thanks for all the work you put into this website!

    So I've just completed this circuit, and it seems to work fine when my guitar volume is very low, up to number 2. I get a nice compression. But when the guitar volume is any higher then I get distortion as well as compression. Tweaking the trimmer does not help, there's just too much amplification somewhere. Any ideas what I should check??

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    1. Me too. Did you solve it? Thanks. (And i have another problem that i'll write in another post in this page). Thanks.

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  8. Replies
    1. Turns out my problem was that I accidentally used a 20k trim pot instead of a 2k!

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  9. is it possible to replace all the 1uFs with non-polar ones?

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  10. I have a problem. It sounds very low. I made it with 3904.

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  11. xcuse my ignorance but what does the acronym C of the 500 piùk potentiometer mean?

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  12. ok, built it on pcb. with 1uf electro, ca3080. I have 2 problems.
    1) A little distortion when i play very loud on the strings.
    2) At any volume, in background, i hear a hiss/buzz that rises and lowers in volume (like sine wave).
    Tips?
    Thanks.

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    1. respecto a la cuestion que mete distorsion lo podes regular con el trimpot si no me equivoco

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  13. I´ve just build this, its my third build, but I can´t make it work. I have some uotput on the amp but extremely low, with the level full up. Any help? Thanks

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  14. I´ve built this twice with 2n3904 transistors first worked nicely but with the second I pick up an FM radio to the point that it make it useless, any ideas what could it be?

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  15. BOA TARDE. ALGUEM TEM UMA MOD PARA O MODO BRIGHT COM CHAVE SPDT?
    GRATO?

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  16. BOA NOITE.COMO POSSO AGREGAR UM CONTROLE DE BLEND?
    GRATO.

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