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8.ADJUSTMENT
PROCEDURE
Note: This instrument has been precisely adjusted at the factory. Therefore, do not change the position of any variable
resistors other than those necessary for servicing.
(}
(2
1)
(4)
{5)
(6:
(i)
Power supply (KLM-297)
Use
a digital
multi-meter
to check
power
supply
leads (possible on any of the circuit boards) which
should
measure
+15V
(+14.7
~ £15.8V) and +5V
(£4.7V
~ £5.3V).
Check KLM-301 +5V (above ground) directly with a
digital
multi-meter
and
adjust
VR-1
to
obtain
5.000V {+0.001V),
Also ascertain
that the -5V supply is -4.995 ~
-6.005V.
Key assigner (KLM-300)
Assign mode:
Switch away from test position, then
reset before proceeding.
1) At assign mode 1, play one key at a time and
ascertain
that the
LEDs
light up in the order:
D,~ Dg.
2) At assign mode 2, play two or more keys at once,
then release them and ascertain that the LEDs
light up beginning from the position of the last
key released.
KBD
SPLIT:
Check
each
section
(synthe,
brass,
strings) as follows.
1) KBD
SPLIT at «>— all 61 keys sound,
2) KBD
SPLIT at « —only
lower
two
octaves
sound,
3) KBD
SPLIT at
sound.
4) Check to see that there is a clear and accurate
split between C3 and B2 for all 8 units. If not,
adjust VR-1 as necessary.
b—only
upper
three
octaves
Programmer (KLM-292)
With EG INT (EG INTENSITY) at 0, adjust VR-1
so
that
EG
INT
CV
(302-24-4
or 292-43-3)
is
0.00V (£60mv).
With
EG
INT at -5, adjust VR-2 so that the EG
INT CV is +5.00V (+60mV).
With
EG
INT at +5, ascertain that EG
INT CV
is -5.00V (£60mV).
Adjust VR-3 if these tolerances cannot be met.
Reset
EG
INT to standard
0 setting after adjust-
ment.
PW/PWM
CV adjustment
Set VCO
1 scale to 16', waveform to PW, and PW/
PWM to 10. Use a digital multi-meter to ascertain
that PW/PWM
CV
(301-25-1
or 292-43-6)
is 2.9V
{£50mV). Adjust VR-4 if necessary.
Synthesizer (KLM-302)
Offset check and adjustment
1) Set VCO waveform
to m, set cutoff frequency
to O (and set other controls to standard settings}.
Check
SY-SIG
OUT
(302-24-13)
with oscillo-
scope (0.1 sec/em, 50mV/cm}.
2) Play any single key and ascertain that the DC
output pulse is within £60mV for units O~7.
(2)
(4
(5)
3) If tolerances
are not met, set assign mode to 2,
and adjust VR-1 for the unit in question.
4) After finishing, return assign mode to 1 and cut-
off frequency to 10.
VCA check and adjustment
1) Set VCO 1 waveform to Mand check SY-SIG
OUT
(302-24-13) with an oscilloscope (1 msec/
em, 0,65V/cem).
2) Play key C3 and ascertain that sawtooth
wave-
form amplitude
is 0.65Vp-p
(+0.05V) for units
o~7.
3) If tolerances
are not met, adjust VR-4 for the
unit in question.
4) After finishing, set waveform to PW,
Resonance adjustment
1) Set PW/PWM
to 10, cutoff freq to'5, and reso-
nance
to 8. Measure
cutoff freq CV (302-24-1)
with a digital multi-meter and adjust cutoff freq
and cutoff freq fine to obtain OmV (+10mV).
2) Measure resonance CV (302-24-3) with the multi-
meter
and
adjust
resonance
to
obtain
8.00V
{£80mV).
3) Measure
SY-SIG
OUT
(302-24-13)
with
an
oscilloscope (1 msec/em, 0.15V/em).
Play any single key and ascertain that the VCF
waveform
amplitude
{sine
wave)
is 0.15Vp-p
(£10mV).
4) If tolerances
are
not met, adjust VR-3
for the
unit in question.
Cutoff frequency adjustment
1) Set resonance to 10, PW/PWM to 10, and cutoff
freq to about
6.3
(ascertaining
that
this gives
OmV
+10mV).
Measure SY-SIG
OUT
(302-24-
13) with an oscilloscope (1msec/em, 0.1V/cm)
and a frequency counter.
2) Play any single key and adjust VR-2 so that the
filter
oscillation
frequency
(measured
with
WT-12) is C=523Hz for units O~7.
3) Adjust cutoff freq and cutoff freq fine to obtain
3.00V
(£10mV)
for the cutoff freq CV
(302-
24-1).
4) Play any single key and adjust VR-7 for units O~
7 to obtain C=4186Hz for the filter oscillation
frequency.
5) With cutoff freq CV (302-24-1) at OmV (£10mV),
adjust cutoff
freq fine to obtain
C=523Hz
for
the oscillation frequency of unit 0.
6) Repeat steps 2 through 5 as many times as neces-
sary to reduce deviation to within +5 cents.
KBD
TRACK adjustment
1) Set KBD
TRACK
to FULL,
PW/PWM
to 10,
cutoff freq to about 6.3, and resonance to 10,
2) Play G3 and adjust cutoff freq fine to obtain
C=523Hz (measured with WT-12) for the oscilla-
tion frequency of unit 0.
3) Adjust VR-2 for units
1~7 so that each unit's
oscillation
frequency
is C=523Hz,
under the
same conditions as above.
19
{6
(7
it}
)
4) Play G4 and adjust VR-5 for units O~7 so that
each unit's oscillation frequency is C= 1109Hz.
5) Repeat steps 3 and 4 as many times as necessary
to reduce deviation to within £5 cents,
6) Check from C1 through C6 by ear to make sure
it sounds approximately like a scale. (No need to
use WT-12.)
7) Set KBD
TRACK
to HALF
and
check to see
that it changes to a 1/4 scale.
8) After finishing, switch KBD
TRACK to OFF.
EG
INTENSITY check and adjustment
1) Set cutoff frequency to 0, EG intensity to +5,
PW/PWM
to 10, and
resonance
to 10. Check
SY-SIG
OUT with an oscilloscope (20usec/cm,
0.1V/em) and a frequency counter.
2) Play any single key and ascertain that the oscilla-
tion frequency for units O~7 is 5.5kHz~6,0kHz.
If not within these tolerances, adjust VR-6.
3) After finishing, set EG INT to O, cutoff freq to
10, PW/PWM to 5, and resonance to 0.
EG check and adjustment
1) Set attack to 10 and sustain to 0. Play any eight
keys simultaneously and ascertain that the attack
time
is 20~25
seconds.
If not
within
these
tolerances, use a digital multi-meter to measure
the potential difference between the +5V power
supply and the attack common
line (the chart
pattern
closest to the keyboard
side). Adjust
VR-8 in accordance with the chart in figure 1.
2) Set attack to 0, decay to 10, and sustain to 0.
Play any single key and ascertain that the decay
time is 20~30 seconds. If not within these toler-
ances,
use a digital multi-meter to check the
potential
difference
between
the
+5V
power
supply
and the decay common
line (the chart
pattern after attack). Adjust VR-9 in accordance
with the chart in figure 1.
3) With attack at 0 and decay at Q, turn sustain
from
0 to 10 and check to see that there is a
smooth change in sustain level for units O~7.
4) Set attack
to 0, decay to 0, and sustain to 0.
With
release
time
at about
5 seconds,
there
should be no greater than about 1 second error
between units.
5) After finishing, return
release to O to return to
the standard setting.
Presets
1) Play keyboard, using piano 1,2, and clav.
2) Based on the data on the following page, check
and
adjust test
points
on
the page after next.
Adjust circled points only; others should only be
checked. Adjustment voltages are valid up to
two places.
Voltage
Figure 1, Attack and decay voltage values vs. temperature.
260mV
250mv
240mv
230mV
220mv
Temperature
Tolerance: Within +1mV of value on graph
[Iv]
pest
PIANO 1 | PIANO 2
Vv
point
'cnn
1_|
vco2scALe
| +125
4° | +5
OFF
|+5
OFF
vco1.
2 | wave Form | -1-25 PW | -1.25 Pw | -1.25 Pw
3 | veo1scaLe
|o
ai
-5
16
{5
16
@_|
Preset vor | +2
4
[42
4 | -2
2
©_|
pwrewm
5
3.95
(+2,.6V}
6 | Keb TRACK
[+5 HALF | -5 FULL
|o
OFF
7__|
LFo sPeED
-10 (LOW SPEED)
DETUNE
0
0
0
© _| sustain
5
5
4.3
€ | RESONANCE
| +5
43.07
+5
@_|
cuTOFF FREQ
+2.74
41.94
43.86
© | RELEASE
+0.64
40.18
5
@ | DEcAY
#4
5
5
@ | EG Int
+0.65
-0.66
~08
| @ | attack
43.2
45
+5
16_|
EG MODE
+5
SN
O: Need adjustment,
Others require check only.
|
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KLM-292
OBOE
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