Dr Quack

An envelope filter based on the Dr. Q.

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5 Responses to “Dr Quack”

  1. Matt Says:

    How come this uses a different IC than the schematic and diagram on GGG and GeoFex? They call for a TL072, but I could only find a TL082. Will the TL082 replace the TL072 in the GGG version? And can I use the TL082 in your schematic? Yours looks cleaneer.

  2. Matt Says:

    Also, I hate to be a pest, but can you post a parts list for your diagrams? Thanks for the great blog!

  3. Kevin Says:

    Please can you direct me to a circuit diagram. I can not get hold of the 4558. Can you suggest an equivalent.

    Regards Kevin

  4. Jukka Says:

    Yes the TL082 will work for this circuit, also TL072, LTC1448, MC4558 or other general purpose dual op, with the same pin connections, they might differ a little in sound, the TL072 is a low noise op-amp, and is my favourite, but has no problem using the others if I don’t have the TL072 home.

  5. Gabriel Says:

    i’m sorry for my stuped question but i wanna know what is for that key between the led lamp and 25K potenciometer. because there is only one button in the pedal.


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