Korg Mono/Poly - Page 21

3)
VCO-2,
3,
4
adjustment.
Perform adjustment
in the same way as
for VCO-1
VR positions are as listed
below.
VC01
VC02
VC03 VC04
VR102
VR202
VR302 VR402
VR103 VR203 VR303 VR403
VR104 VR204 VR304 VR404
VR101
VR201 VR301
VR401
.
VCA LEVEL
adjustment (KLM-355).
Connect oscilloscope
(DC 0.5V, 1msec.) to
SIG
OUT
or
PHONE OUT. Use settings
listed below.
Settings:
VCO-4
LEVEL
... 10
(VC01,
2,
3
are
at
0.)
WAVEFORM A
OCTAVE
16'
Play C3 and confirm
1.5Vp-p. Adjust VCA
GAIN
VR10
if necessary.
5. NOISE check.
Set
CUTOFF to
10,
RESONANCE
to
f
and VCOI,
2, 3,
4 to 0.
Set NOISE
LEVEL
at
10 and confirm 3.0~5.0Vp-p.
After check, turn
NOISE LEVEL back to 0.
VCF check and
adjustment.
1)
OFFSET adjustment.
Set
RESONANCE to
0,
CUTOFF to 5.
Use
DVM
to
check both sides
of R10. Adjust
VR-19
to
obtain
0.000V ±10mV.
2)
VCF
LEVEL,
Fc
adjustment
Set
VC04
to 0,
RESONANCE to
10,
EG INT
to
0,
CUTOFF
to
10.
Use
oscilloscope at
DC2V, 0.1msec.
Put
any single key
into HOLD. Confirm cycle T=*
140/isec. and oscillation level is within
7Vp-p
—
11Vp-p (figure
1).
3.5-
5.5cm
l
C
1.3-1.5cm
*i
O.lmsec/div.
Fig.
1.
If
necessary, adjust VR18
for
Fc.
If
oscillation
level
is off,
adjust
VR3 to obtain 20Vp-p
at both
sides of
KLM-355 R10
(with
CUTOFF
at 10 and
RESOat
10).
Confirm
that
oscillation begins
when
RESO-
NANCE is
turned
up to
7 or above.
7.
RESONANCE
VCA check and
adjustment.
Settings:
Oscilloscope
DC
0.5V,
1msec.
VCOI
LEVEL
10
HOLD
ON
CUTOFF
10
Leave others at normal setting.
Play
C3
vary the RESONANCE
setting
and
confirm
oscilloscope traces
as
shown in figure
2.
n
1-1.5Vp-p
(2 -3cm)
1
lUu.
P^i
v
1.5-2.0Vp-p
(3 -4cm)
RESOatO
RESOat
5
Fig.
2.
8.
If indication is less than
1Vp-p when RESONANCE
is
at
5,
then set
VCO
1, 2, 3,
and
4
LEVEL
to
0,
CUTOFF to
5,
and RESONANCE to 10. Then adjust
KLM-355 VR4 to
obtain 60mVp-p across
both
sides
of KLM-355 R44.
VCF
EG
check.
Set
oscilloscope to
DC 2V, 1msec, VCO LEVEL to
10,
HOLD to
OFF,
VCA
EG A to
0,
D to
0,
S to
10,
and R to 10. Then
confirm changes in
oscillation
frequency as
listed below.
CUTOFF
RES
EG
INT
A D S
R
10 10
-5
3 3 2
3
10
+5
3 3 2 3
Oscilloscope waveform
OFF
J
\
High
Low
High
Wb
Low
Low High
Low
9.
VCF KBD
TRACK
check and adjustment.
Set
oscilloscope
to DC2V, 1msec, VCO
1-4 LEVEL
to
0,
RESONANCE
to 10,
EG INT to
0,
KBD
TRACK
to
10,
HOLD
to
ON. Play C3
and turn
CUTOFF
to
obtain
about 4cm
(250Hz),
then play C4
and
confirm
1.1cm ±0.3cm
(1250Hz~414Hz)
as
in
figure
3.
\<z
4cm
*\
J
1. 1cm 1
0.3cm
Fig. 3.
21