Tuesday, 23 June 2020

MXR Distortion Plus


14 comments:

  1. Sorry... tedious question...
    What would the upshot be if I was to use a couple of 1n4148 diodes?

    Thank you 🤗

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    1. You'll end up with a DOD 250 Pre Amp.:-) More volume and a bit more crunch!

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  2. Thank you kindly! I'm gonna do that - because that's what I've got!

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  3. Hello,
    It's funny : I wanted to try to build the "JET" part of the Coron Jet Flanger (a flanger with a distortion thrown in), using the schematic from Dirk Hendrick, and just noticed that you recently posted the MXR Dist+ layout : The Coron Jet distortion is supposed to be based on the Dod250/Mxr Dist+.

    I tried to check the differences in component values between his schematic and your layout, but it seems that the Coron features one more little section which I am struggling to adapt to your layout... Would you mind checking the Coron schematic and see if it is doable?

    - The schematic is here : https://www.dirk-hendrik.com/coron.html
    http://www.dirk-hendrik.com/coron_jet.pdf

    - The component values mods I noticed :
    The 3 electros are 10µF
    The 10nF input cap is 47nF
    The 1nF is 4.7nF
    The 4.7k resistor is 3.3k
    3 x 1M resistors are now 510k

    - It's easy to follow the first half of Dirk Hendrick schematic. Where I am struggling, it is after the diodes : there are two 10µF caps and a 500k pot, and then a 470R resistor leaving the opamp... Also, I don't get the pinouts of the opamp (on your layout, pin5 is not connected to anything, while on Dirk Hendrick layout, "everything" goes to pin5)...

    Would you mind checking the schematic, to see if it would be easy to adapt your layout to this one (I'd be curious to know if both sound identical).
    Thank you!

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  4. So the Distortion+ uses a single opamp. The schematic is very similar on the first half, but it is using a dual opamp, and it also uses the other side. It wouldn't be real quick to adapt this layout, because the pinout is very different.

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    Replies
    1. Hi, Michael,
      Thank you for your answer : that explains everything :)

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  5. I built it today with a coule mods to make it warmer and more bassy : I love it!

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  6. https://youtu.be/kx85XjvdJUE

    Perfect. Thank you!!

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  7. (I added a reverse logarithmic pot for the gain. The sweep is much better.)

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  8. If I were to add a tone control at the output is it a simple matter of changing volume 1 to vol 1/tone1, changing the 1nf to a different value (22nf), and wiring tone lugs 2/3 to the top row around A8?

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    Replies
    1. I think that sounds about right Ben, would look something like

      https://www.muzique.com/lab/swtc.htm

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    2. Let me know how you get on, I've tried adding passive tone controls to pedals but they never sound right. This method looks pretty straight forward. Cheers

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    3. I've always been a fan of the Earthquaker White Light. The weight control on it is pretty effective.

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