One - it's 86% scale of the original, just a bit smaller with thinner not-quite-mini keys (no aftertouch :-), it has a MIDI and USB connection which allows you to play the thing from the DAW or external MIDI gear. The third thing is build quality, while the mini jacks feel solid enough, there is definitely some play in the knobs. This however is down to the bend in the pot shaft we're told - as the Alps pots are soldered onto the surface of the board and braced with a sort of metal collar that goes right through.
If your unfamiliar with the voice architecture of the MS20 here's a brief outline:
Two VCO's: VCO 1 - Sine, Tri, Saw, Pulse and White noise (32/16/8/4 range) VCO 2 - Saw , Square and thin Square plus Ring Mod (16/8/4/2 range) tunable +/- 5 semi-tones
Two filters High pass and Low pass are both resonant and scream like a banshee when cranked. A single LFO, two envelopes on HADSR (Hold, Attack, Decay, Sustain, Release), and DAR - (Delay, Attack,Release). Patchbay - gives access to some discrete semi modular patching plus Sample and Hold, White or Pink Noise, Pitch to voltage input with envelope follower.
I can testify that all this is exactly as it was on the original - warts and all. By which I mean, like the original you can't modulate the Pulse Width, you can't modulate VCO 1+2 separately or patch envelope 1 control out unless you want it inverse.
Of course these limitations are part of the charm of the original so it doesn't seem right to be overly critical of such an OAP.
Questions, Questions... Does it sound like the original? Yes it does, about as close as something can to electronics that are over 30 years old and have aged. But a remarkably good job.
What about MIDI? Very basic, note on/off are all that are supported, no controllers mapped to knobs - which don't output CC either, just a basic in and out. Keyboard transmits over MIDI but only note information.
CV/GATE Again, it's like the original - it talks in Hz/Volt - not what most Eurorack equipment needs for Control Voltage of oscillators. This means no it wont interface with your Doepfer gear - but it will talk to an an MS20 (see the video).
Shame really, but as the internal synth operates this way, changing that would have meant it wasn't an MS20 I guess. Someone needs to make a cheap format convertor sharpish. Harvestman have the English Tear, and I believe Doepfer do something too.
USB Power? Nope, the unit requires 9v and comes with a power supply - USB does not have enough juice to power it.
Can I Buy One? Probably, though supplies are limited so perhaps not immediately, it retails for around £499/$599/€575.
Korg are making them as fast as they can, but it's a more complex process to make these than stamping out circuit boards we're told.
What Do I Think? Apart from the fact that my original is now worth less, Korg should be given kudos for remaking this - quite a challenge I imagine and resisting the temptation to put a GM bank in it or something shows excellent self control - though I would like to have seen PWM and V/Oct CV.
The choices in the sub £500 quid analog mono are hotting up, but nothing sounds like an MS20 apart from this and the original.