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control interacts with the others to produce a wide range of
sounds. Continuing practice will make you fluent in moving from
one sound to another quickly and accurately. In the meantime,
here are some hints to help you achieve this sooner.
TUNING AIDS
1. In tuning the oscillators, it helps to leave the VCF and
VCA open--that way you don't have to keep striking a key
as if you were tuning a guitar or piano.
2. To tune a module to concert, or "standard" pitch, set the
keyboard TRANSPOSE switch to 8' and depress the middle A
while you tune one oscillator to your external pitch
source. Then release the A. The second VCO can be tuned
to the first; use sawtooth waves for all tuning proce-
dures.
3. Tune only two oscillators at a time, using the same
oscillator as your reference each time. For example,
make VCO I in the first module your reference; then after
you have tuned VCO 2, close the audio from VCO 2 and open
VCO 1 in the second module and tune it, and finally close
that input and open the one from VCO 2 in the second mod-
ule and tune VCO 2. Then open all four to check.
4. The beat frequency will always double as you go up by
octaves. So after you have tuned at 8', go up to 4' and
then 2' to check on the tuning of each oscillator; read-
just if necessary. If you ever find that an oscillator
seems to go out of tune as you go down again, you may
need to calibrate it.
5. It is generally useful to tune the two VCO's in a single
module to some interval other than unison. Try octaves,
twelfths, fifteenths, and other harmonic intervals
within a three-octave range. Drop the level of the
higher VCO when tuning; it will make the beats more audi-
ble.
6. You needn't attempt to get the beat frequency actually
down to ZERO. "Zero-beat" is an approximate phrase for
anything less than one beat every second or two. In many
cases you will actually want the slight "singing" qual-
ity produced by this slow beating--this is literally a
phasing effect. (Use two sawtooth waves in unison and
play them through short-decay percussive envelopes: lis-
ten to the color changes as the two signals go in and out
of phase.)
7. SETTING PITCHES IN A SEQUENCE. Suppose that you want to
set a pitch sequence for VOICE ONE under the control of
SEQ 1. With both modules open, and assuming they have
already been tuned to unison from the keyboard, switch
