Korg POLYSIX Service Manual

(3)
MG
adjustment.
Leaving
other controls
at
the normal
setting,
set MG
FREQUENCY
to
10,
LEVEL
to
10,
and
MOD SW to
VC
A.
1
)
Observe connector
CN03-5
on oscilloscope.
Fig.
2.
2)
Adjust
VR2 to
obtain
1Vp-p<±5%)
level;
adjust
VR5
to
obtain
frequency
of
50Hz
(20msec
±10%).
If
these
values
cannot
be
obtained
after
replacing 1C
LM 13600,
adjust
R78
and
R52
respectively.
3)
Leave
the other
controls at
the
same
settings as
above,
but
change
MG
FREQUENCY
to 0.
Confirm
a
cycle of
1
0
~
40
sec.
Leave
other
controls
at
same
settings
but
change
MG
FREQUENCY
to
4,
and
DELAY to
10.
Confirm
that the
waveform
appears 8
—
12
seconds
after a
key is
depressed.
Fig.
3.
(LEVEL
IVp-p;
frequency
about
10Hz.)
(4)
PW/PWM
check
and
adjustment.
Set
waveform to
PW
and
PWM
SPEED to
0,
and
PW/PWM to
10.
1
)
Connect
oscilloscope
and
DVM to
CN05-1 1
.
2)
Adjust
VR3 to
obtain
+2.2V (±1%).
3)
Change
WAVEFORM
to
PWM
and
PWM SPEED
to 10.
Adjust
VR4
to
obtain a
frequency
of
20Hz.
Use
resistor
inseries
with
VR4
if
adjustment
cannot
be
obtained
in
the same
way as
for
the MG.
Fig.
4.
4)
At
this
time
confirm that
there is a
DC
component of
40.2
~
40.5V.
4.
KLM-366
check and adjustment.
Obtain
ground at
TP5.
(1
)
VCF
offset
adjustment.
Leaving
other
controls
at
standard
settings, set
WAVE-
FORM
to
PW
and
PW/PWM to 10,
1)
Use
oscilloscope
or DVM to check
Q5
(2SC945)
collector.
7)
Adjust
VR7
to
obtain OmV ±2mV.
3)
Repeat
steps 1 & 2
for units No. 0
~
No. 5.
(2)
VCA
level
adjustment.
Set OCTAVE
to
4;
leave others
at
normal setting.
1
)
Connect
oscilloscope to
SIG OUT (TP-1
).
2)
Play
C3
and
adjust
VR9 to obtain a
sawtooth
wave-
form
amplitude
of IVp-p
(±5%).
3)
Repeat
for
units No. 0
~
No.
5.
(3)
VCF
RESONANCE
adjustment.
Set OCTAVE
to
8,
WAVEFORM to
PW, and
PW/PWM
to
10.
Check
CN05-7
with DVM
and adjust to
obtain
0.000V
±20mV.
Check CN05-1
1
with
DVM
and
adjust RESONANCE
VR
to
obtain
8.000V
±20mV.
Leave other
controls at
normal
setting.
1)
Check
SIG OUT
(TP1)
with
oscilloscope and
fre-
quency
counter.
2)
Play any
single
key
and adjust
VR6
so
that
the
VCF
waveform
amplitude is
300mVp-p
±20mV.
3)
Repeat
for units
No.
0
~
No.
5.
(4)
VCF fo
adjustment.
Set
RESONANCE
to
10;
leave others at same
setting
as
above
(3).
1)
Check
oscillation
frequency with
frequency counter
and
tuner (WT-12,
properly calibrated,
chromatic
dial set to C).
2)
Adjust
VR8 to
obtain
/o=523Hz (±10
cent).
3)
Repeat
for units
No.
0
~
No. 5.
4)
Turn
CUTOFF
from
0
to 10
and check to
see that
each
unit's
oscillation
frequency
is
10
—
25Hz at 0
and 19
~
24kHz at
10;
amplitude
should be at
least
300mVp-p
throughout.
(5)
EG
INTENSITY
adjustment.
Set
WAVEFORM
to
PW,
PW/PWM to
10,
CUTOFF to
0,
RESONANCE to
10,
EG
INT to
±5. Leave
others
at
normal setting.
1)
Check SIG
OUT
(TP-1)
with
oscilloscope and
fre-
quency
counter.
2)
Play any single
key and
adjust
VR4
to
obtain an
oscillation
frequency
of
5kHz
(±500Hz)
for units
No. 0
~
No. 5.
3)
Set
EG
INT
to
+3 and
check to
see that
there is
-no
wide
variation
in
pitch
between
units No. 0
~
No.
5.
4)
Set
octave to
4',
RESONANCE to
0,
EG
INT to
4-5,
SUSTAIN
to
0,
DECAY
to 5.
Leave
others at
same
setting as
3)
above.
Check
to see
that
there is no
click
noise for units
No. 0
~
No.
5.
(6)
KBD
TRACK
adjustment.
Set
OCTAVE to
16',
connect
DVM to
CN05-6,
and
adjust
KBD TRACK
VR to
obtain
41.6V.

Korg POLYSIX Specifications

General

Type	Analog
Polyphony	6 voices
Oscillators	1 VCO per voice
Effects	Chorus, Phaser, Ensemble
Keyboard	61 keys
Memory	32 patches
Year Released	1981
Waveforms	Sawtooth, Pulse
Filter	24dB/octave Low Pass Filter
LFO	Triangle