the
middle console has 2 units which I call CHROMATIC GENERATOR.
the photo shows one half of the middle console, which is one complete
chromatic generator.
left
part:
12 VCOs with individual tuning, FM-inputs & outputs. all 12 VCOs can
be free running or can be tuned with one switch in 1/2tone steps.
frequency-dividing these 12 VCOs internal by 2, 4, 8, & 16 bgives all
60 1/2tones within a 5 octave range simultaneous (all square waves),
which leads to the right part.
right
part:
this part contains all 61 1/2tones of the 5-octave range, each 1/2tone
has a CV-input for it's VCA (61 VCAs, built with paia's hex-vca), a
volume-knob & an A/B-position switch.
the lowest horizontal line has the 12 1/2tones oft the lowest octave,
the second line the half tones one octave up etc., the 5th line is the
highest octave. a 5-octave 1/2tone-system includes 26 of 32 possible
harmonics of the harmonic set (with analog accuracy, not digital precision),
so this means additive synthesis with square waves.
with the 2 * 8 ADSRs of the upper console, gated by the individual gates
of the 2 analog sequencers, I can do dynamic additive synthesis with
square waves.
this
may seem complicated, but it works.
more
about additive synthesis with square waves see:
B:Jacoby "walsh functions: a digital fourier saries" in BYTE,
09.77 & in the BYTE Book of Computer Music, 1979.
the
chromatic generator has 27 outputs, which can be used simoultaneous,
among them:
- outputs of each of the 5 octave-lines
- 1 output for all of the 1/2tones whose loudness pots are "on"
- an output for odd harmonics
- an output for even harmonics
- an output for subharmonics
- an output for 1/2tones whose switch is in position A
- an output for 1/2tones whose switch is in position B
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