I've uploaded my Approximation of the Mastotron on bass to the SA cloud. It's called GMC Mastotron - Gated Fuzz. It's my 1st attempt at approximating this pedal on my Ultrawave, so I might revise it in a few days with a version that uses morph expression between two specific settings. Currently, I've enabled the Midi Expression to dial in an approximation of the pedal's Tilt EQ, which is curious that it's a EQ tilt with 2 different frequency centres. The 7 Diode Harder Gate sounded most like the distortion characteristics of the Mastotron...however it's not quite the same, but it's the closest I've got so far.
The analogue pedal is very organic and changes it's character a lot depending on the source signal and how hard one hits it. Both it's EQ responce, grit and compression all change a lot depending on it's input. So it sounds vey different between basses or if I pop a wet octaver in front of it. So I've set my patch to emulate my default Mastotron finger style playing sound. This patch on my Ultrawave, it sounds pretty much the same regardless of which bass I'm using (and I have a few!). However, if I want to use an Octave wet only input, I need to change various settings to match the analogue pedal's sound. So I've set the expression pedal to vary the tilt. If I shove the expression pedal to about 80% max and nudge up the treble and sustain to about 1'oclock, I get a similar sound that I get from the analogue pedal in tat context. If I want to add a chorus to this glorious noise...then I need to max out the expression to 100% and nudge the Sustain and Treble to about 2'oclock.
If you're not using Expression over Midi, you'll need to disable that feature and twiddle with the B/M/T controls to suit.
To my ear, it's not an exact copy, but it's a very close approximation. It might even be close enough for me to finally drop the Mastotron from my board. I have a Titan II pedal that's just was curious...so I might see if I can model that pedal into two morph settings too.
Sorry there's no soundcloud files for these yet. Maybe I'll get a chance to actually record something useful this weekend!