Service manual

FIGURE 4-2 TWO CHANNEL OSCILLOSCOPE TEST SETUP FOR TUNING
should be used if a two channel oscilloscope is
available. In the test setup of Figure 4-2, display
height and audio level are independent and it is not
necessary to trigger the oscilloscope off of a composite
waveform. Trigger the oscilloscope off the lower
of the two frequencies.
4.2.2 POWER SUPPLY ADJUSTMENT (Minitmoog Only)
a) Connect DVM across pins J (+) and K (-)
of oscillator board No. 5 and turn +9 volt adjust trimpot
R4 on main board No. 1 (Figure 4-3) until the +9 volt
line is exactly +9.000 V ±10 mv.
b) Connect DVM across pins L (-) and K (+) of
oscillator board No. 5 and verify that the -9 volt line is
-9.000 V ±200 mv.
4.2.3 KEYBOARD CURRENT ADJUSTMENT
a) Connect DVM across pins A5 (+) and A6 (-)
OCT1 OSCILLATOR AMPLITUDE
KEYBOARD ADJ A HIGH SCALE RANGE DECAY
ADJ RIO FREQUENCY R17 R16 R190
R79 +9V ADJ \VIBRATO ADJUST / R14
UNDER
IC11
0
VCA
BAL
R160
JUNCTION
R165ANDR166
AMPLITUDE
R162 \ ATTACK
IC22 \ \ R174
08 / R47 JUNCTION R130 R21 \ Q41 R132
R64 SQUARE OF R44 BAND OCT2 \ CENTER
WAVE ADJ ANDR119 WIDTH ADJ JUNCTION FREQ
ADJUST R149 AND C30 ADJ
\
Q20 R98 R139 R105
FILTER LOW PASS FILTER
DECAY CUTOFF ATTACK
FIGURE 4-3 MAIN BOARD NO. 1 ADJUSTMENT CONTROLS AND OSCILLOSCOPE TEST POINT LOCA TIONS
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