AW: RE: [AH] Wanted Korg MS-20 or Arp 2600

[Haible Juergen]

>Are there any "hard to find" parts for the Korg MS-20? Seemingly most
pieces
>that have available parts and are close to the original issue price are
>reissued or remade on limited basis... t
>
>[...]
>
>...so I wonder why no one scrambles for MS-20 clones? (except for Paul
Perry
>with his Frostwave filter box)... maybe it's still not "in demand"
enough...
>
>__________
>CHAD GOULD


Until recently, I guess the market prices for a MS-20 was not that high. I
can
remember a time not too far from now when a Minimoog was "the real thing" 
we could not afford, but the MS-20 was a "toy for everyone". AH archives
will surely back this up.

This was an overrating of the Mini, and underrating of the MS-20, of course
(;->).
IMO, everybody needs a Moog filter just to have *that* special sound, but
you can spend hours and hours with the interaction of the two filters in the
MS-20
and still find new timbres - it's much more on the experimental side than,
say, a 
Minimoog.

So with increasing market value, or "awareness of its potential", building
clones
makes more and more sense, nowadays.
No Problem, if you want the filter, meanwhile: Paul Perry offers a stand
alone 
filter in large stompbox shape, and MOTM has a filter module that does an
emulation of the original as close as I can think of (;->). So your lust for
"that
sound" can be satisfied.

Building a *whole* MS-20 is a different thing. First of all, manufacturing
of a synth
with sloped panel and keyboard is not cheap at all today, and building an
expander
module doesn't hit the point. I mean, you can rather buy the filter module
alone
then. Having a compact little patchable like the MS-20 is a nice thing that
goes
*beyond* the sound of its filter, but reducing it to a rackmount box would
spoil
this extra advantage.

If I were to build an MS-20 clone today ...
Well, this is not a theoretical question. I'm actually doing it - sort of.
(Not commercially,
sorry, just a one-off on veroboard with custom made front panel and a
salvaged
keyboard of a dead SH-2000). It will be *not* an exact clone of the MS-20,
because
IMO the original has a few design flaws that I would not like to copy. I'm
aware
that limitations have their charm, too, but oh well, who has not dreamed of
getting
rid of them:
(1) The MS-20's VCOs tend to interlock, i.e. they have a tiny amount of soft
sync
that cannot be switched off. Very slow VCO beating ? - not on the original.
(2) The "good" envelope is hard wired to the VCA, so my famous setting 
ADSR-> VCF and AR -> VCA is problematic. (You can at least add both EG's
for the VCA on the MS-20, but well ...)
(3) The saw waves of the LFO are lacking the sharp transients that you need
to
emulate LFO clocked, fast AD-envelope filter sweeps. (The LFO topology does
not
allow for an easy mod, either)
(4) The "Sample &Hold" is rather a "Track & Hold" on the MS-20. Which is a
nice
*option*, but you *normally* want a normal S&H, without adjusting the LFO
shape.
(5) No aftertouch. IMO, a synth so compact and ergonomic like the MS-20
cries
for adding AT to make it an even better performance instrument.

There may be more points. And before you send your flames, let me clarify
that
I absolutely love the (original) MS-20, and deeply regret that I sold mine.
I just
wanted to say that now as I'm building something similar, I try not to copy
what I
consider design flaws as well. And in general, I want the new instrument to
incorporate features of the earlier Korgs (700 etc.), too. And things like
S&H modulation
or delay vibrato will be hard wired, and not only available thru a patch
panel.
And this old SH-2000 keyboard will give me aftertouch.

BTW, in case you wondered, I will *not* abandon the V/Hz concept. 
Portamento is not the same in V/Oct, for instance. And I'll even incorporate
the nice
autobend feature of the Minikorg.

JH.