
Not sure how much of a clone of the real thing this is, but it definitely looks impressive. Title link takes you to more details and shots.
"The picture above shows the Synthi A clone almost complete. Some mods I have added are arrowed above. First on the oscillators 2+3 I have added audio/LFO frequency switching. On oscillator 1 there is variable synch with oscillators 2 or 3 (switchable). This synch sounds excellent..! In addition I have added switches on all 3 oscilltors that allow a choice of either frequency or waveshape modulation via the control input columns on the matrix patchboard. This is a really worthwhile mod in my opinion..lets you have pulsewidth modulation of oscillators 2 and/or 3 via oscillator 1 for example. I added 3 tiny gren leds above the corresponding matrix columns on the frontpanel. When you switch from frequency to waveshape modulation..the corresponding led lights up to remind you of that."