Check And Adjustment - Korg Poly-800II Service Manual

ADJUSTMENT PROCEDURE
Caution:
This product has been thoroughly abjusted at the factory
before shipment. Therefore do not abjust anything other
than those VRs required for servicing.
BEFORE making any calibration abjustments, Be sure
that test data is loaded into POLY-800.
The following setting chart shows the program data used
for servece testing. After inputting the data, save it on tape
for future time saving convenience.
PROGRAM no. 11 (noise level):
Parameter:
Value:
17
0
18
1
31
99
32
0
33
0
35
0
37
15
61
0
62
0
63
31
64
0
65
31
66
0
83
0
84
0
PROGRAM
Parameter:
Value:
PROGRAM
Parameter:
Value:
PROGRAM
Parameter:
Value:
no.
11
2
no.
11
2
no.
11
2
21
12
2
13
12
2
14
12
2
(master oscillator):
13 14
1 0
15 16
0 0
(cut off):
13 14
1 0
15 16
0 0
17
30
17
31
(resonance):
13 14
1 0
15 16
0 0
17
31
18
1
18
1
18
1
31
60
31
12
31
99
32
0
32
12
32
15
33
0
33
2
33
0
35
0
35
0
35
0
38
0
37
0
37
0
41
0
41
0
41
0
42
0
42
0
42
0
43
31
43
31
43
31
44
0
44
0
44
0
45
31
45
31
45
31
46
0
46
0
46
0
83
0
83
0
81
15
84
0
84
0
82 83 84
0 0 0
PROGRAM
Parameter:
Value:
PROGRAM
Parameter:
Value:
no.
11
1
no.
11
1
15
12
1
16
12
1
(delay 1):
13 14 15 16
1111
(delay 2):
13 14 15 16
1111
17
31
17
31
18
1
18
1
31
99
31
99
32
0
32
0
33
0
33
0
35
1
35
1
37
0
37
0
41
0
41
0
42
0
42
0
43
7
43
7
44
0
44
0
45
0
45
0
46
0
46
0
61
0
61
0
71
50
71
0
72
15
72
0
73
0
73
0
74
0
74
0
75
15
75
15
76
0
76
0
77
0
77
0
81
0
81
0
82
0
82
0
83
0
83
0
84
0
84
0
85
2
85
2
86
1
86
1
81
1
81
1
88
0
88
0
1. Power supply circuit (KLM-1032)
Be sure that the specified AC adapter is used: 9V, 300mA,
1) +5V check and adjustment:
Use a DVM (digital voltmeter) to check KLM-596 connector
CN6 Pin 6 and confirm + 5V (=h 0.005V). Adjust VR1 if
necessary.
2) -5V check:
Use a DVM to check KLM-596 connector CN6 Pin 8 and con
firm -5V (within - 4.7V ~ -5.7V)
2. D/A converter check and adjustment (KLM-1032) ]
With joystick bend control at center position: (BEND INT MAX)
connect DVM to KLM-596 IC10 (TL062) Pin 7 and confirm
1.986V ± 0.005V. Adjust VR4 if necessary.
Reference data:
3.990V for an upward pitch bend and
0.020V for a downward pitch bend.
Note:
Adjustment is easiest in the joystick circuit although the idea
is to obtain a 4V ± 0.004V output from IC 38 (TL062) by ad
justing the D/A converter when IC 81C55 port A output is all
high.
13. Noise level check and adjustment: (KLM-1032)
1) Select program no. 11.
2) Depress C3 key and set to HOLD.
3) Connect on oscilloscope to KLM-596 CN6A 3 pin and con
firm noise level of 0.3Vp-p (±20%).
4) Adjust VR3 if necessary.