Friday, 22 April 2016

THAT Jam Compressor

Here is a DIY project similar to the Carl Martin Compressor Limiter.
There are 2 layouts: a large one that works at 9V and a smaller one where you need to decide a way to feed +/- 12V to the circuit (just a charge pump with regulators wouldn't work with this circuit).
You should read the original threads from FSB here and here before building this effect.
Good luck!

15 comments:

  1. Cooll! I guess this will be perfect for my Eurorack. It's hard to find good stripboards for my new enclosure and +/-12v supply. I worry the signals of my modular will be somewhat to hot for this though.

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  2. 330nF is missing a cut under it.

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  3. Thanks Robert.
    It has been fixed.

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  4. is this the right chip? http://www.mouser.com/ProductDetail/THAT/4301P20-U/?qs=sGAEpiMZZMvxTCYhU%252bW9mSHGcoR5HnTi6ZnSaFFEg3U%3d

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    1. That should be the right one.
      Wow! It is expensive!

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    2. Small Bear has it for 9.75 each.

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  5. This is a great layout. But I'd recommend to buy the kit (or pcb) at uk-electronic.de.

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  6. Verified!
    here's the pics:
    http://hpics.li/e2a4209
    http://hpics.li/f3842d9
    http://hpics.li/475668b

    Great comp, better than my Mad Prof Forest Green Comp!

    Family pic with the FGC:
    http://hpics.li/674601f

    No Noise, a great build! Will stay at home.

    Many Thanks for the layout Alex.

    Jack_Vester

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    1. Cool! Thanks Jack!
      Looks cool!

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    2. How do you properly adjust the precision trimmers?

      I read the info here http://www.musiker-board.de/threads/workshop-that-jam-kompressor-f%C3%BCr-bass-und-gitarre-platinen-version-1-4.388884/#post4699621 it mentions setting one at 50 ohms and the other at 20 ohms, but I'm not sure what that achieves.

      There must be a reason the design uses trimmers instead of fixed resistors there, but why?

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    3. I just set the trimmers to have exactly +12,0V and -12,0V

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  7. This comment has been removed by the author.

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    1. thanks for the tip man! That was very helpful!

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  8. Hi Guys! Currently working on this pedal too! How do you guys set the 50k trimmer? is it at 12v too? Thanks!

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