Saturday, July 11, 2020

PETE CORNISH: SS-3 Soft Sustain

Pete Cornish's excellent take on the MXR Distortion +  the Pete Cornish SS-3 Soft Sustain.

I used a vintage tin can IC in the first gain stage, and while it added a bit of noise, it certainly added some grit and character.  There's certainly nothing wrong with a standard single op-amp - potentially better, depending on what you want out of this.

The Cornish buffer is included in this layout.

PETE CORNISH SS-3 SOFT SUSTAIN - VERO LAYOUT


PETE CORNISH SS-3 SOFT SUSTAIN GUITAR EFFECT VERO LAYOUT


SCHEMATIC

A schematic from Aion Electronics and their tracing journal can be found here.  This is quite possibly a better source of information for what the SS-2 should be, as there are a couple of different values for capacitors etc.


POTENTIAL MODS

While building this, I tried a few different things with the diodes - maybe too many things.   

Try adding clipping diodes on the first opamp like a Tube Screamer, and swap between these and the hard clippers (sounds bad when on simultaneously).   Different combinations of germanium and silicon are also fun.  There are so many options to try.  I did a crazy layout with a bunch of switching for this, but I gave up on it as it was just too many options for a pedal that already sounds really good as it is.



Build photos below are care of Palelite from Freestompboxes.   It's a really nice-looking build using a slightly earlier version of the layout above.



LTSPICE



Frequency response of treble and locut on a medium gain setting



Same again but with sustain on 100%



Frequency response at various gain settings, with tone control completely open




Output trace at various gain settings, with tone / locut controls completely open



Output trace at various gain settings, with tone / locut controls completely open, at various stages in the circuit





5 comments:

  1. I see 9 eco on the picture but only 8 on the Vero lay out?

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    1. Excellent spotting - that was built with an older layout. On the older layout I included power to the LED on/off light. As part of this, I included an extra resistor and capacitor to help prevent switch pop, and I like the LED turning on slower.

      http://www.muzique.com/lab/led.htm It's the second circuit listed here

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  2. Thanxs for the replies I give it u try

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  3. What enclosures did you use on it? its big, so much better to lay the wiring and the board,very clean...Which are the dimensions??

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    1. I'm not sure what size that enclosure is - the photo is a pedal that was made by someone else using this layout. Maybe a 1590XX? 145m x 121mm x 39mm I think you could probably cramm it in a 1590BB. I'll check measurements later.

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