[sdiy] analogue physical modelling organ dream

[JH.]

I dream of building another fully polyphonic instrument right now.
It's a dream, mind you, and very unlikely to be realised. But I said that
about other dreams in the past as well.

I think of a small analogue physical modelling organ. It's easy to make
quite convincing
flute sounds from a delay line, a 1-pole filter, and some nonlinear
circuitry. The big
problem is making this track over some octaves without going out of tune.

So if I'd use the same approach as in the PE-1000 - using a lot of voices
instead
of ane tracking voice - the flute might become an array of flutes - a single
register
of a pipe organ - and all the tracking problems, plus the concept of a VCO
itself - would be nonexistent.

I phantasize about using a single PUT for the oscillators, half of a CD4013
to
get complementary clock pulses, a BBD without any optimisation (no bias
trim, no balance trim, to keep things simple), a simple LPF built from a R
and
a C (no more VCF needed ...), plus a handfull of transistors for the
nonlinear
part.

At the moment, I'm making experiments with a PM flute (i.e. tracking), to
find out what results I get with a very simple nonlinear circuit.

Well, I'm aware that with something like 49 BBDs I would only have *one*
register of an organ. The final goal would hardly be a huge church organ -
more likely something like a 2 or 3 register portativ.

JH.