Completely functional and in great working order, no sticky keys, few minor scratchy pots. Nostalgic vintage patina, many cosmetic scuffs and scratches. The real deal, exactly how we like it:)

The original Korg MS-20 is a semi-modular, monophonic analog synthesizer released by Korg in 1978. [1]Core Specifications

• Type: Semi-modular monophonic analog synthesizer 
• Keyboard: 37 full-size keys (C to C, 3 octaves) 
• Polyphony: Monophonic 
• Oscillators (VCO): 2 VCOs
• • VCO 1: Triangle wave, sawtooth wave, square wave (with pulse width modulation / PWM), pink noise, white noise
  • VCO 2: Sawtooth wave, square wave, narrow pulse wave, and ring modulator
• Filters (VCF): High-pass and low-pass filters with peak/resonance and self-oscillation capabilities (using early Korg-35 filter components in original units) 
• Envelope Generators (EG): 2 envelope generators (EG1 and EG2 with hold/delay features) 
• Low Frequency Oscillator (LFO): 1 LFO (modulating VCO and VCF)
• External Signal Processor (ESP): Allows external audio sources (such as guitars or vocals) to track pitch and trigger the synth or run through the filters 
• Patch Panel: 1/4" (6.35 mm) phone jacks for semi-modular signal routing and patching 
• Power Supply: Built-in AC power transformer (voltage varies by regional model, such as 100V, 220V, or 120V) 

The MS-20 was one of Korg's first major successful portable analog monosynths and even today it is still a great little machine! The MS-20 is the big brother to the MS-10. It is an analog two-oscillator monophonic lead and bass synth with hard wired and patchable connections. The hard-wiring can be overridden however, using patch-cords. This type of hard-wired but patchable design was similar to the ARP 2600 of the late seventies. Of course the 2600 was much bigger and better. But the MS-20 offered a lot of flexible control and great sounds at a more affordable price.

In addition to two analog oscillators, the MS-20 featured two resonant VCFs (filters), two VCAs, sample and hold, a noise generator, an assignable mod-wheel and lots of knobs! The VCF (filter) section is capable of high-pass, low-pass, notch and band-reject which is unique and different than your basic lowpass style filter. External sound sources can be routed through the filter section as well. In fact William Ørbit uses the filter in his MS-20 relentlessly to filter and tweak his samples, beats, delay returns, vocals, etc.

There's also a Pitch-CV converter for triggering sounds from external sources. Aphex Twin makes quite a bit of use of this, feeding the input stage of his MS-20s with drum sounds and other untrackable audio to get the synth to make a wide variety of crunch/squawp/screech noises by mistracking the filters, etc.

As for its sounds, the MS-20 sounds great! It makes a great alternative for Minimoog-seekers. The MS-20 is great for just about any type of analog synth sound you could want! Fat round bass sounds, percussive bass or sounds, noise effects, squiggly-bubbly sounds or sinuous-worm leads are all waiting to be unleashed from inside this classic beast. The MS-20 is not only a great sounding instrument, but a great learning-synth. It is fairly easy and intuitive to operate but in doing so you can learn and understand more about synthesis and signal-flow.