via this VEMIA auction
"A very rare and collectable educational model from the makers of the VCS3 and Synthi-AKS. According to Robin Wood there were only around 150 of these instruments made. At first glance it appears deceptively simple, but then you notice the Tim Orr designed-filter has low pass, band pass and high pass outputs, all available simultaneously. The Attack/Decay Trapezoid Generator also has three simultaneous outputs for different modes, and can be triggered from the keyboard, the LFO, an external source via the Envelope Shaper or even patched to recycle automatically. The single VCO too, has three outputs available plus a PWM input and the VCA can be varied continuously between amplitude and ring modulation, so there are a lot of patching possibilities. This particular one is not mint, but is at least 'Good' cosmetically. 
Please have a look at the photographs and see for yourself. There are some scuffing marks to the outer Spartanite case, but no cracks, chips or structural damage to the plastic. The catches and hinges show some signs of corrosion but are fully functional. The front panel of the Synthi shows some panel wear, for example where the black lines and lettering have been rubbed off in a few places, but the legend is still readable. The membrane keyboard has a split along part of the top edge and near the bottom left-hand corner but this doesn't affect its function. The previous owner left a set of old batteries in it and these leaked into the rear of the case (but not onto the circuit boards), so the battery cases have been replaced. I've shown a photo of the interior so you can see that the boards are clean and unaffected by this. The good news is that this instrument has been fully overhauled by Lucid in March 2014 and is in perfect operational condition. The membrane keyboard (which usually fails on these) has been repaired and is working as is the touch-slider above it. All slide pots have been opened and cleaned. The Synthi comes with an original set of EMS patch leads, plus an additional set of five stacking leads and a UK 240V to 18V DC power supply."
