KORG Delta

images via this auction
"Korg's fully polyphonic Delta is a pretty unique synth. The synth section allows you to combine oscillator footages and has its own ADSR, while the string section has an EQ and a simple AD envelope generator. The two can be combined so you can have a percussive synth sound followed by swelling strings. Both sections go through a gorgeous sounding filter that switches between low pass and band pass. The filter can be swept from the joystick, which can also modulate both the filter and oscillator with the LFO or, oddly, the noise source. Overall a nice surprise and sonically unique compared to Korg's Poly-Ensemble, Lambda, or Sigma."

Some samples at the auction while it's up.