Service manual

c) Repeat paragraphs 4.2.12 and 4.2.13 several
times as scale and high end adjustments interact.
4.2.14 OSCILLATOR B OCTAVE TRANSPOSITION
(Minitmoog Only)
1 OCT tab switch down
2 OCT tab switch up
"B" PITCH control vertical (in deadband)
a) Zero beat oscillator B with oscillator A using
range trimpot R504, Figure 4-5 (oscillators A and B
in unison).
b)Set "B" PITCH control fully clockwise to 10
and zero beat oscillator B with oscillator A using
octave trimpot R510, Figure 4-5 (oscillator B one
octave above oscillator A).
NOTE
Allow a small adjustment latitude by tuning
oscillator B slightly sharp in step b (approx
imately 2 Hz beat rate). Thus oscillator B
will be in tune with oscillator A slightly
before the control reaches full rotation.
4.3 VOICE CALIBRATION
4.3.1 PREPARATION
Set the following controls to their initial position
as follows: Satellite panel marking differences are in
parentheses.
4.3.2 SQUARE WAVE DUTY CYCLE
a) Observe waveform at junction of R44 and
R119 (Figure 4-3).
b) Depress CLARINET (REED HOLLOW, Satellite)
tab switch and adjust square wave adjust trimpot R47
for a symmetrical square wave as shown in Figure 4-6.
EXACTLY 50%
DUTY CYCLE
FIGURE 46 SQUARE WAVE AT JUNCTION
OF R44ANDR119
4.3.3 BAND PASS FILTER RESONANCE (Q) AND CENTER
FREQUENCY (Fc)
a) Observe waveform at source of Q41 (Figure
4-3) with CLARINET (REED HOLLOW, Satellite)
tab switch still depressed.
b) Depress 1 OCT tab switch and C key one
octave up from bottom of keyboard and adjust band
width and center frequency trimpots R130 and R132
to obtain waveform shown in Figure 4-7.
4 UNITS
1UNIT
700 USEC (Fc: R132)
4: 1 RATIO (Q: R130)
V^>»-^
FIGURE 4-7 BAND PASS FIL TER Q AND Fc
AT Q41 SOURCE
4.3.4 LOW PASS FILTER CUTOFF FREQUENCY (FL)
a) Raise all tab switches and depress highest key
on keyboard.
b) Set VOLUME slide control all the way up and
adjust low pass cutoff trimpot R139 (Figure 4-3) until
the waveform at output pin 6 of IC22 (top of R162)
is two volts peak-to-peak.
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