PETE CORNISH: SS-2 Soft Sustain

The Pete Cornish SS-2 Soft Sustain is Pete's interpretation of a MXR Distortion +   and it's not a bad one at that (it's very nice actually).  If you prefer a bit more control, try the SS-3, as it has bass and treble controls.  The same overall sound, just more tweakable (if that's a word).

Like all things Pete Cornish related, put the Cornish buffer in front of it and wire it buffered bypass.  Why use two single opamps instead of a dual - I don't know, ask Pete.

I did find that in my SS-3 build, using an old tin can single opamp gave me a certain grit and feel that I just wasn't getting with the modern equivalent, at the cost of a bit more noise.  Both options sounded very good - I could have gone either way really.  

PETE CORNISH SS-2 SOFT SUSTAIN - VERO LAYOUT  

LTSPICE

This is from the PedalPCB trace.

This is the frequency repose at a few different points in the signal path, with the sustain on full.

  

Below is the output, with varying amounts of sustain - as gain changes, so does the frequency response.  One lower gain settings the tone control is really necessary to cut down the high peaks.  Higher gain settings provide a prominent mid-range.  

Sustain on 100%, tone at 0, 50% and 100% 

This gives a clear progression of the signal - sine wave, clipped to a square wave in the first opamp, which is rounded out by the diodes, then it changes quite a bit as soon as it passes the 10n capacitor before the tone control (C5).   Increasing the 10n cap changes the response of the circuit quite a bit.

Here's C5 with some different values - 10n is stock.  As you can see, increasing C5 starts to return the signal to something resembling a square wave again as more low frequencies are allowed to pass.