The Korg MS20 has a unique place in history in that
it was one of the first (and last) affordable 'semi-modular' synths
available. It also shares a place with the Roland TB303 'BassLine'
in that it's 'sound' was derided upon its release but has now reached
almost cult status.
Essentially, it was a pre-patched 2-oscillator successor to the
1-oscillator MS10. However, on the right of the panel was a patchbay
of 1/4" jack sockets that allowed you to insert patch cords
and 'interrupt' the pre-patched signal/control paths. In many respects,
the concept was not unlike that pioneered on the ARP 2600 but where
the MS20 scored was its price - it was a lot cheaper.
However, many regarded the MS20 (myself included!) as a poor man's
2600 and it was dismissed as a bit of a toy synth and side-by-side
with a MiniMoog, the poor old MS20 did sound a bit wimpy by comparison.
But the MS20 found a great deal of favour with those on a budget
who couldn't stretch to a 'proper' synth such as the aforementioned
2600 or MiniMoog and as a result, the MS20 was a big success for
Korg in the mid-70s when it was released.
On the surface, the MS20 had a modest complement of 'modules' but
on closer examination, you'll find two VCOs, two self-oscillating
filters (one lowpass and one highpass which together can be configured
as bandpass or notch-reject filters), a versatile sample+hold unit,
two envelopes (one AR-type with variable note-on delay; another
ADSR-type with variable hold time), an LFO with variable symmetry
waveshapes, a noise generator (with simultaneous white and pink
noise), an assignable modwheel and more. Damn - the thing even had
a pitch-cv convertor! On their own, these would have probably been
enough to secure some degree of success for the humble MS20 but
the addition of the 35-way patch bay opened the way to some outrageous
experimentation that elevated the MS20 above many of its contemporaries.
Of course, then as now, a synth was measured by the tone of its
filters and it has to be said that the MS20's 12dB/Octave filters
did sound a bit limp and fizzy compared with the MiniMoog's beefy
24dB/Octave 'ladder' filters or ARP's 4075 24dB/Octave filter found
in their Odyssey - the sound of the MS20's filters were simply not
the fashion back in the 70s and early 80s!
However, musical fashion is a fickle thing and the sound of the
MS20 became favoured by many including William Orbit and Vince Clarke
amongst many others - the MS20 even provided the foundation for
the music used in the 'Flat Eric' Levis commercial! Nowadays, most
manufacturers of modern analogue synths go to great lengths to provide
an authentic 'Korg filter' in their module line-up and what was
once considered by many as a weak and feeble pretender is now a
highly regarded part of our modern sonic vocabulary.
Korg pursued the concept with the MS50 - a keyboard-less modular
synth expander that retained the basic components of the MS20. They
also developed a step-sequencer, the SQ10, in the same cosmetic