Casio CZ-1 - Page 124

25-6.
VCA
Offset
Voltage
Adjustment
VCC
(
1
)
Connect
a
digital
voltmt
ter
as
indicated
in
tha
following
uble.
(Refer to
checkpoing
(5)
and
(§)
on page
4)
Connection
point
\
VR
to bt
adjusted
Pin 1
of
opamp
and
pin (|)
of
VCA (GNO)
j
VR2
Pin
7
of opamp
and
pin
®
of VCA (GNO)
VR3
(2)
While
the
test
unit
is
not
producing
any sound,
adjust
VR2 and
VR3
so
that
digital
voltmeter
reading
isO±3mV.
Note: Be
sure to
use
a
digital
voltmeter.
25-6.
BBO
Adjustment
(
1
)
Connect
an
oscilloscope as
shown
in
the Uble
below.
(Refer to
checkpoint®,®
and
(5)
on
page
12)
Connection
point
(MA2M
PCB)
Adjustment
VR
Canter
terminal
of VR1
and
pin
1
of
BBO
MN3209-1 (GNO)
VR1
Center
terminal of VR2
and
pin
1
of
BBO
MN320B-2 (GNO)
VR2
Center
terminal
of VR3
and
pin
1
of
BBO
MN3209-3 (GNO)
VR3
VR
7
Center
1MA2M
PCB]
(2)
Set
the oscilloscope on
AC range,
0.1
V/div, and
10jiS/div, then
observe the
waveforms.
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