Yamaha SY-2

via this auction
"The big star here is the filter; it is the same filter that was put in the mighty Yamaha GX-1 (One could debate as to it being Yamaha biggest, most wonderful synth ever; the only contender being the CS-80 but even then, the GX-1 was much more elaborate and expensive). Personally I'd describe this filter as sitting somewhere between the larger Yamaha CS units' filter and that of the MS-20 (But much more musical than the MS20's). It can get extremely resonate (it has both a low-pass AND high-pass filter, both featuring separate resonance controllers) making it great for squelchy basslines. There are lots of control options for this synth, it just takes a little time to wrap your head around what Yamaha thought was a good thing to name a control function and what it actually does. One could liken it to a 1 (maybe 2) VCO synth with 2 envelopes, a LFO, slide, VCF in, touch modulation, Pulsewidth control, etc. The unit also come with the original foot expression pedal for sweeping the filter, volune, etc, the metal stand legs (two poles are missing the plastic parts on the feet but I'm sure you can find those off an old desk or at Home Depot or something. I've never needed them), and the top of the case which latches on, protecting the synth for transport (as you can see the synth is built like a flight case). There is a section inside the top to store the legs as well."