Can anybody help with a DynaComp clone that is not varying in sensitivity?

Discussion in 'Effects, Pedals, Strings & Things' started by soma89, Jan 1, 2020.

  1. soma89

    soma89 Member

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    Hello everyone, Happy 2020!

    I am working on a dynacomp/ross clone that does not have a functioning sensitivity (sustain) knob. It kinda just stays at the same highly compressed state even when I fool around with the adjustment knob.
    I checked everything through a scope. Nothing on the board looks burned.

    Any ideas?
    I do understand some electronics jargon so feel free to get a bit technical on me.

    Thanks in advance
     
  2. Hawkmoon269

    Hawkmoon269 Supporting Member

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    Pick it up and shake it.
     
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  3. coltonius

    coltonius SeƱor Member

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    Is it a PCB project? Vero?
     
  4. soma89

    soma89 Member

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    Its actually a pedal thats already made. Basic DynaComp Schematic
     
  5. David B

    David B Silver Supporting Member

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    Disconnect the sensitivity/sustain pot and measure that it goes from 0-500k (it's likely reverse taper), then check that the leads that connect to the pot are also connected to 27k and Q5. If that all works keep tracing the sensitivity circuit with the schematic.
     
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  6. soma89

    soma89 Member

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    The pot measures fine.

    Its connected to 27k but I'm not sure what else to look for at Q5, as the compression is happening but its just not varying. So I would imagine there would be signal all along that path, no?
     

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