Roland OD-20 Operating and maintenance manual

SERVICE NOTES
Issued by RJA
Copyright © 2002 ROLAND CORPORATION
All rights reserved. No part of this publication may be reproduced in any form without the written permission
of ROLAND CORPORATION.
Printed in Japan (0800) (NB)
17058015E0
Apr.2002 OD-20(T)
TABLE OF CONTENTS
SPECIFIC.ATIONS............................................................2
LOCATION OF CONTROLS ..........................................4
LOCATION OF CONTROLS PARTS LIST ...................5
EXPLODED VIEW ............................................................6
EXPLODED VIEW PARTS LIST .....................................9
PARTS LIST......................................................................10
CHECKING THE VERSION NUMBER.......................13
RESTORING THE FACTORY SETTINGS...................13
TEST MODE.....................................................................13
BLOCK DIAGRAM.........................................................16
CIRCUIT BOARD(JACK)...............................................18
CIRCUIT BOARD(PANEL) ...........................................19
CIRCUIT DIAGRAM(JACK) .........................................20
CIRCUIT DIAGRAM(PANEL)......................................22
(T)

2
Apr.2002
SPECIFIC.ATIONS
OD-20: Overdrive/Distortion
Nominal Input Level
-20 dBu
Input Impedance
1 MΩ
Nominal Output Level
-20 dBu
Output Impedance
1 kΩ
Recommended Load Impedance
10 kΩor greater
Dynamic Range
102 dB (IHF-A typ.)
Controls
EFFECT ON/OFF Pedal
MANUAL/MEMORY Pedal
DRIVE Knob
BOTTOM Knob
TONE Knob
LEVEL Knob
ATTACK SHAPE Knob
HEAVY OCTAVE Knob
TYPE Knob
VARIATION Button
AMP CTRL (amp control) Button
MEMORY WRITE Button
MEMORY SELECT Button
Indicators
POWER Indicator (serves also as battery check indicator)
EFFECT ON/OFF Indicator
MANUAL Indicator
MEMORY Indicator
VARIATION Indicator
AMP CTRL (amp control) Indicator
MEMORY Number Indicator (1-4)
Connectors
INPUT Jack
AMP CTRL (amp control) Jack
LINE OUT/PHONES Jack
OUTPUT Jack
AC Adaptor Jack (DC 9 V)
Power Supply
DC 9 V: Dry Battery (R6/LR6 (AA) type) x 6
AC Adaptor
Current Draw
85 mA (9 V max.)
* Expected battery life under continuous use:
Carbon: 8 hours
Alkaline: 20 hours
These figures will vary depending on the actual conditions of use.
Dimensions
173 (W) x 158 (D) x 57 (H) mm
6-13/16 (W) x 6-1/4 (D) x 2-1/4 (H) inches
Weight
1.1 kg / 2 lbs 7 oz (including batteries)
Accessories
Owner’s Manual
English :G6017351
Japanese :G6017350
Leaflet (“USING THE UNIT SAFELY,” “IMPORTANT NOTES,” and
“Information”):(********)
Dry battery (LR6 (AA) type) x 6:(********)
* We recommend that alkaline batteries be used when replacing the batteries.
Options
AC Adaptor (PSA-series)
*0dBu = 0.775 Vrms
* In the interest of product improvement, the specifications and/or appearance of
this unit are subject to change without prior notice.

3
OD-20(T)

4
Apr.2002
LOCATION OF CONTROLS
fig.front
fig.rear
1
2
3
6
7910
5
8
11
12
13
14
15
16
17
4
236
457
18

5
OD-20(T)
LOCATION OF CONTROLS PARTS LIST
[Front]
[Rear]
No. PART CODE PART NAME DESCRIPTION Q’TY
1 H5029855 SCREW M4X8 HEXAGON BUTTON HEAD 4
2 G2477122 R-KNOB 5
F3279802 POTENTIOMETERNO CLICK 50KB RD901-40-125F-B54-00D 5
3 G247751001 VGA KEYTOP S BLACK WITH LENS 2
4 G2477122 R-KNOB 1
F3279803 POTENTIOMETER 11 CLICKS 50KB RD901-40-125F-B54-11D 1
5 H5029851 PEDAL SHAFT 1
6 1502928100 LED (RED) L-34HDSL 3
7 G2187540 PEDAL L 1
8 G2017180 CASE 1
9 G2217171 LED PANEL 1
10 G2187541 PEDAL R 1
11 H5029852 SCREW 4M3 FEBZC HEXAGON SOCKET BUTTON HEAD 2
12 G2357116 PEDAL PLATE 62X53 2
13 F5029126 POWER LED L-113GDT 1
14 G247751301 VGA KEYTOP S WITHOUT LENS 2
15 1502928100 LED (RED) L-34HDSL 4
16 G2217170 PANEL 1
17 G2477122 R-KNOB 1
F3279819 POTENTIOMETER CENTER CLICK 50KB RD901-40-125F-B54-0CD 1
No. PART CODE PART NAME DESCRIPTION Q’TY
1 13449150MF PHONE JACK (STEREO) HTJ-064-12D 3
2 G2537552 LABEL CAUTION 1
3 G2217172 REAR PANEL 1
4 G2017621 BATTERY COVER 1
5 G2017148 BOTTOM COVER 1
6 G2357118 BOTTOM FOOT 1
7 F3449415 ADAPTOR JACK KM02009AB 1
8 13449155MF PHONE JACK (MONO) HTJ-064-12I 1

6
Apr.2002
EXPLODED VIEW
fig.expro1
33
32
26
24
c
k
21
b
d
23
25
b
e
f

7
OD-20(T)
fig.expro2
a
11
18
a
12
18
11
16
j
14
15
17
10
13

8
Apr.2002
fig.expro3
1
2
5
3
i
4
g
hRIGHT SIDE
LEFT SIDE
9
6
7
8

9
OD-20(T)
EXPLODED VIEW PARTS LIST
[Part]
[Screw]
No. PART CODE PART NAME DESCRIPTION Q’TY
1 G2017180 CASE 1
2 G2357111 CUSHION R 2
3 H5029851 PEDAL SHAFT 2
4 2215770201 PEDAL GUIDE BUSH 215-702 2
5 2217710900 COIL SPRING 214-109 2
6 G2357116 PEDAL PLATE 62X53 2
7 G2357115 PEDAL FOOT M8 2
8 G2187541 PEDAL R 1
9 G2187540 PEDAL L 1
10 G2017148 BOTTOM COVER 1
11 G2357118 BOTTOM FOOT 2
12 G2017621 BATTERY COVER 1
13 G2017620 BATTERY CASE 1
14 G2177308 BATTERY TERMINAL(+) 1
15 G2177309 BATTERY TERMINAL(-) 1
16 G2177307 BATTERY TERMINAL(+-) 1
17 G2257130 BATTERY INSULATING SHEET 1
18 G2537552 LABEL CAUTION QUICK MANUAL 1
21 G2477122 R-KNOB 7
23 G2257129 INSULATING SHEET 1
24 G2217170 PANEL 1
25 G2217172 REAR PANEL 1
26 G2217171 LED PANEL 1
32 G247751301 VGA KEYTOP S WITHOUT LENS 2
33 G247751001 VGA KEYTOP S BLACK WITH LENS 2
No. PART CODE PART NAME DESCRIPTION Q’TY
a H5029115 SCREW 3X8 PAN TAPTITE-2 FEBZC 7
b H5019110 SCREW M3X6 PAN TAPTITE-2 FEZC 9
c H5029855 SCREW M4X8 HEXAGON SOCKET BUTTON HEAD FENI 4
d H5039205 WASHER 12.5X9.5X0.5/0.9 INTERNAL TOOTH FENI 4
e H5039112 WASHER M9 4
f H5039510 NUT M9X12X2 FENI 4
g H5029852 SCREW 4M3 FEBZC HEXAGON SOCKET BUTTON HEAD 2
h H5039413 NYLON WASHER M4.1X7.5X0.5 BLACK 2
i H5039414 NYLON WASHER M5.1X9.5X0.5 BLACK 2
j H5019430 SCREW M2.6X5 BINDING HEAD TAPTITE FEZC 2
k H5039521 VR ACCESSORY NUT M7 7

10
Apr.2002
PARTS LIST
fig.part1e
SAFETY PRECAUTIONS:
The parts marked have
safety-related characteristics. Use
only listed parts for replacement.
CONSIDERATION ON PARTS ORDRING
When ordering any parts listed in the parts list, please specify the following items in the order sheet.
QTY PART NUMBER DESCRIPTION MODEL NUMBER
Ex. 10 22575241 Sharp Key C-20/50
15 2247017300 Knob (orange) DAC-15D
Failure to completely fill the above items with correct number and description will result in delayed or even
undelivered replacement.
NOTE: The parts marked # are new. (initial parts)
CASING
G2357116 PEDAL PLATE 62X53 2
G2017620 BATTERY CASE 1
G2017621 BATTERY COVER 1
G2017148 BOTTOM COVER 1
G2357118 BOTTOM FOOT 2
# G2017180 CASE 1
# G2217171 LED PANEL 1
# G2217170 PANEL 1
# G2187541 PEDAL R 1
# G2187540 PEDAL L 1
H5029851 PEDAL SHAFT 2
# G2217172 REAR PANEL 1
“KNOB,BUTTON”
G2477122 R-KNOB 7
G247751001 VGA KEYTOP S BLACK WITH LENS 2
G247751301 VGA KEYTOP S WITHOUT LENS 2
SWITCH
01780101 SKQKAB TACT SWITCH SW3, SW4, SW5, SW6 on PB 4
13129778 SKQKAH TACT SWITCH SW1, SW2 on PB 2
JACK,EXT TERMINAL
13449150MF HTJ-064-12D PHONE JACK (STEREO) JK1, JK2, JK3 on JB 3
13449155MF HTJ-064-12I PHONE JACK (MONO) JK4 on JB 1
F3449415 KM02009AB ADAPTOR JACK JK5 on JB 1
PWB ASSY
# E 75D693P000 JACK PWB ASSY
# 75D693M000 PANEL PWB ASSY
IC
# 02897545 MN101C30AHD OD-20 VER1.00 IC(CPU 8BIT) IC6 on JB 1
# F5209123 S-80930ALMP-DAT-T2 IC (REST) IC7 on JB 1
F5179604 CAT24WC02J IC (EEPROM) IC4 on JB 1
02565501 TC220CCA0AF-B01(MR3) IC (DSP) IC5 on JB 1
# F5179125 S-8520E33MC-BJS-T2 IC (DC-DC) IC8 on JB 1
15289109 M5216FP-600D IC (BIPOLAR OP AMP) IC10, IC11 on JB 2
15189261 M5218AFP-600E IC (BIPOLAR OP AMP) IC3 on JB 1
00346445 NJM2100M(TE3) IC (BIPOLAR OP AMP) IC1 on JB 1
02451434 AK4552VT IC (AD/DA) IC2 on JB 1
TRANSISTOR
00679045 2SA1298-Y(TE85R) TRANSISTOR Q5 on JB 1
15309104 2SA1586-GR(TE85R) TRANSISTOR Q4 on JB 1
15319108 2SC-3324GR-TE85R TRANSISTOR Q3, Q12 on JB 2
00562012 2SC3265-Y(TE85R) TRANSISTOR Q7 on JB 1
15319107 2SC4116-GR(TE85R) TRANSISTOR Q6, Q9, Q10 on JB 3
F5139608 IRF7606 POWER MOS FET Q11 on JB 1
# F5329530 2SK879Y FET TRANSISTOR Q2, Q8 on JB 2
15329103 2SK880GR-TE85R FET TRANSISTOR Q1 on JB 1
DIODE
02562878 02DZ5.1-Y(TPH3) ZENER DIODE D8 on JB 1
01019534 1SS355 TE-17 SWITCHING DIODE D1, D4, D6, D10 on JB 4
F5029126 L-113GDT POWER LED LED2 on PB 1

11
OD-20(T)
1502928100 L-34HDSL LED (RED) LED3, 4, 5, 8, 9, 10, 11 on PB 7
F5029117 L-312LRD LED LED6, 7 on PB 2
15339119 1SS-352 DIODE D2 on JB 1
00783034 1SS294(TE85L) DIODE D3 on JB 1
15339120 1SS302 DIODE DA3 on JB 1
F5339137 SS14 VF=0.45V DIODE D5, D7 on JB 2
DIODE
RESISTOR
F5419707 CRN34101J RESISTOR ARRAY RA5,6 on JB 2
# F5399951 68(1/2W) CHIP RESISTOR (1/2W) R64, R68 on JB 2
# F2569127 MINISMDC075 POLY SWITCH R48 on JB 1
00566867 RPC05T 100 J MTL.FILM RESISTOR R37, R76, R77, R79 on JB 4
00567023 RPC05T 101 J MTL.FILM RESISTOR R51 on JB 1
00567156 RPC05T 102 J MTL.FILM RESISTOR R6, R61 on JB 2
00567289 RPC05T 103 J MTL.FILM RESISTOR R1, R7, R11, R12, R13, R14, R15, R17, R19, 25
00567412 RPC05T 104 J MTL.FILM RESISTOR R10, R28, R45, R67, R75, R78, R82, R83, R86 12
00567556 RPC05T 105 J MTL.FILM RESISTOR R2, R3, R5, R27, R29, R44, R60 on JB 7
00567290 RPC05T 123 J MTL.FILM RESISTOR R25, R34 on JB 12
00567301 RPC05T 153 J MTL.FILM RESISTOR R23, R36 on JB 2
00567190 RPC05T 222 J MTL.FILM RESISTOR R57 on JB 1
00567334 RPC05T 273 J MTL.FILM RESISTOR R59 on JB 1
00566934 RPC05T 330 J MTL.FILM RESISTOR R54 on JB 1
00567089 RPC05T 331 J MTL.FILM RESISTOR R62, R69, R82 on JB 3
00567367 RPC05T 393 J MTL.FILM RESISTOR R30 on JB 1
00567245 RPC05T 472 J MTL.FILM RESISTOR R9, R66, R88 on JB 3
00567378 RPC05T 473 J MTL.FILM RESISTOR R8, R16, R21, R26, R31, R41, R47, R52, R53, 11
00567501 RPC05T 474 J MTL.FILM RESISTOR R4, R74 on JB 2
00567134 RPC05T 681 J MTL.FILM RESISTOR R72 on JB 1
# F3829270 27(2W) METAL OXIDE RESISTOR R18, 22 on JB 2
F5429365 10K OHM F RANK (1%) CHIP RESISTOR R24 on JB 1
F5429386 150K F (1608TYPE) CHIP RESISTOR R20 on JB 1
# F5419740 CRN34473J CHIP ARRAY RESISTOR RA4 on JB 1
# F5419741 CRN34681J CHIP ARRAY RESISTOR RA2,3 on JB 2
POTENTIOMETER
# F3279819 RD901-40-125F-B54-0CD 50KB ROTARY POT. W/CENTER CLICK VR2 on PB 1
F3279802 RD901-40-125F-B54-00D POTENTIOMETERNO CLICK 50KB VR1, VR3, VR4, VR5, VR6 on PB 5
F3279803 RD901-40-125F-B54-11D POTENTIOMETER 11 CLICKS 50KB VR7 on PB 1
CAPACITOR
02341489 ECPU1C474MA5 MYLAR CAPACITOR(SUBMI-
CRON)
1
# F5349704 ECPU1C474MA5 MYLAR CAPACITOR (SUBMI-
CRON)
C1 on JB 1
# F5359732 GRM39B102J50PT CHIP CAPACITOR (1608 TYPE) C80 on JB 1
F5359780 GRM39B103K50PT CHIP CAPACITOR (1608 TYPE) C55, C56, C57, C58, C59, C60, C61, C72 on J 8
# F5359382 GRM39B182J50PT CHIP CAPACITOR (1608 TYPE) C89, C95 on JB 2
F5359740 GRM39B222K50PT CHIP CAPACITOR (1608 TYPE) C5, C9 on JB 2
# F5359812 GRM39B473J50PT CHIP CAPACITOR (1608 TYPE) C17, C33 on JB 2
# F5359372 GRM39B683J50PT CHIP CAPACITOR (1608 TYPE) C67 on JB 1
F5359720 GRM39CH101J50PT CHIP CAPACITOR (1608 TYPE) C6 on JB 1
# F5359803 GRM39CH151J50PT CHIP CAPACITOR (1608 TYPE) C83, C85, C88, C90 on JB 4
# F5359370 GRM39CH180J50PT CHIP CAPACITOR (1608 TYPE) C69 on JB 1
F5359704 GRM39CH220J50PT CHIP CAPACITOR (1608 TYPE) C68, C70, C71 on JB 3
# F5359373 GRM39CH271J50PT CHIP CAPACITOR (1608 TYPE) C12, C13, C22 on JB 3
F5359800 GRM39F104Z25PT CHIP CAPACITOR (1608 TYPE) C11, C21, C24, C26, C30, C32, C35, C36, C37 30
# F3629692 0.22/50V CAPACITOR C87 on JB 1
# F3629695TS 1/50V CAPACITOR C2, C3, C19, C29, C91, C94 on JB 6
# F3629678TS 10/16V CAPACITOR C4, C7, C8, C10, C14, C15, C16, C18, C20, C 14
# 13629550KM 100/16V CAPACITOR C31, C49, C52, C54, C76, C78, C81, C86, C92 9
# 13629509KM 47/16V CAPACITOR C34, C74 on JB 2
INDUCTOR,COIL,FILTER
F2449216 SLF7045T-151MR40 SMD COIL L3 on JB 1
02563478 NFM4516P13C204F EMI FILTER C48 on JB 1
F2449210 SLF7032T-4R7M1R7-2(4.7UH) COIL L2 on JB 1
CRYSTAL,RESONATOR
02673278 CX-49G 11.2896MHZ CRYSTAL X2 on JB 1
F5299108 HC-49SM 8MHZ CRYSTAL X1 on JB 1
CONNECTOR
F3439160 53015-0210 2P P=2MM CONNECTOR CN4 on JB 1
F3439165 A2001WR2-10P CONNECTOR CN1 on JB 1
# F3439200 A2001WR2-15P CONNECTOR CN2 on JB 1

12
Apr.2002
WIRING,CABLE
G3487163 WIRING BATTERY L=80MM 2P 1
# G3467251 WIRING 15P L=52MM P=2MM CN2 on PB 1
# G3487421 WIRING 10P L=40MM P=2MM CN1 on PB 1
G3477146 RIBBON CABLE 3P L=40X5X5 MM P=2MM CN3 on JB 1
SCREWS
H5019110 SCREW M3X6 PAN TAPPING-2 FEZC 10
H5029115 SCREW 3X8 PAN TAPPING-2 FEBZC 7
H5039205 WASHER 12.5X9.5X0.5/0.9 INTERNAL TOOTH FENI 4
H5029852 SCREW 4M3 FEBZC HEXAGON SOCKET BUTTON HEAD 2
# H5029855 SCREW M4X8 HEXAGON BUTTON HEAD 4
H5039510 NUT M9X12X2 FENI 4
H5039413 NYLON WASHER M4.1X7.5X0.5 BLACK 2
H5039414 NYLON WASHER M5.1X9.5X0.5 BLACK 2
H5019430 SCREW M2.6X5 BINDING HEAD TAPTITE FEZC 2
H5039521 VR ACCESSORY NUT M7 7
H5039112 WASHER M9 4
PACKING
# G2627250 PACKING CASE 1
G2607212 PACKING CASE LOWER 1
G2237614 REAR PAD 1
G2237613 SIDE PAD 1
MISCELLANEOUS
G2357115 PEDAL FOOT M8 2
H2369427 LED SPACER H=8MM 4
2215770201 PEDAL GUIDE BUSH 215-702 2
2217710900 COIL SPRING 214-109 2
G2257130 BATTERY INSULATING SHEET 1
G2177308 BATTERY TERMINAL(+) 1
G2177307 BATTERY TERMINAL(+-) 1
G2177309 BATTERY TERMINAL(-) 1
G2357111 CUSHION R 2
G2257129 INSULATING SHEET CENTER 1
# G2537552 LABEL CAUTION 1
G2197126 LED GUIDE 1
ACCESSORIES (Standard)
# G6017350 OWNER’S MANUAL JAPANESE 1
# ******** ALKALINE BATTERY LR6SG-P2 3
# G6017351 OWNER’S MANUAL ENGLISH 1

13
OD-20(T)
CHECKING THE VERSION
NUMBER
After you enter test mode, perform step 5.
1. Turn all knobs to MIN (all the way to the left).
2. While holding down the left pedal and the right pedal, insert the 9V plug
into DC IN.
At this time, only the POWER LED will light.
3. Release the left and right pedals. The EFFECT ON/OFF LED will blink.
4. Within four seconds, press the left pedal and then the right pedal.
If you were successful in entering test mode, the EFFECT ON/OFF LED,
MANUAL LED, and MEMORY LED will light.
5. Set the TYPE volume to METAL/LOUD.
. The version number will be indicated as follows.
For Ver1.00, only the MEMORY 2 LED will light.
(The integer portion is indicated by the MEMORY 1 and 2 LEDs
1: MEMORY 1 LED: dark MEMORY 2 LED: lit
2: MEMORY 1 LED: lit MEMORY 2 LED: dark
3: MEMORY 1 LED: lit MEMORY 2 LED: lit
The first decimal place is indicated by the MEMORY 3 and 4 LEDs
0: MEMORY 3 LED: dark MEMORY 4 LED: dark
1: MEMORY 3 LED: dark MEMORY 4 LED: lit
2: MEMORY 3 LED: lit MEMORY 4 LED: dark
3: MEMORY 3 LED: lit MEMORY 4 LED: lit
The second decimal place is indicated by the MANUAL LED and
MEMORY LED
0: MANUAL LED: dark MEMORY LED: dark
1: MANUAL LED: dark MEMORY LED: lit
2: MANUAL LED: lit MEMORY LED: dark
3: MANUAL LED: lit MEMORY LED: lit )
RESTORING THE FACTORY
SETTINGS
Returning Settings to Their Factory Defaults
You can restore the memories (1-4), pedal mode settings, and the MEMORY
Number Indication to their original factory values.
Memory Settings
Memory 1 LOUD
Memory 2 LEAD
Memory 3 OD-1
Memory 4 STACK
Pedal Mode
1 (MANUAL -> MEMORY 1 -> MEMORY 2 -> MEMORY 3 -> MEMORY 4 ->
MANUAL)
MEMORY Number Indication
Lighting Pattern 1(Only the indicator for the selected memory lights up.)
Carrying out the following procedure completely clears the content currently
stored in the memories (1-4).
1. Switch off the power.
Disconnect the connection plug from the INPUT jack.
2. While holding down the WRITE button, switch on the power.
Insert the connection plug into the INPUT jack.
When you release the button, the MEMORY Number indicators blink.
3. Press the MEMORY WRITE button.
After the MEMORY Number indicators begin blinking rapidly, the
setting is stored in memory and the unit returns to its ordinary state.
* To cancel the setting change, operate the EFFECT ON/OFF pedal or the
MANUAL/MEMORY pedal before pressing the MEMORY WRITE button.
The unit will return to its ordinary state.
TEST MODE
Required items
1. Oscillator
2. Noise meter
3. Oscilloscope
4. Monitor amp (e.g., MA-12)
5. Guitar amp (with a channel-switching jack)
6. Stereo plug
7. 47kΩshort plug
1. How to enter test mode
1. Turn all knobs to MIN (all the way to the left).
Connect a short plug (47kΩ) to INPUT.
2. While holding down the left pedal and right pedal, insert the 9V plug into
DC IN.
At this time, only the POWER LED will light.
3. Release the left and right pedals. The EFFECT ON/OFF LED will blink.
4. Within four seconds, press the left pedal and then the right pedal.
If you were successful in entering test mode, the EFFECT ON/OFF LED,
MANUAL LED, and MEMORY LED will light.
2. List of test items
1. IC check
2. Switching noise / shock noise check
3. Residual noise check
4. SW and LED check
5. AMP control check
6. VR Check
7. DAC check (includes FET SW (EFFECT)
inspection)
8. DSP thru check
9. Analog mute check (FET SW (DIRECT)
inspection)
10. Version check

14
Apr.2002
3. Test contents
1. IC check
1. When you enter test mode, the DSP(IC5) and EEPROM(IC4) check will
begin automatically.
2. If no problem is found, the EFFECT ON/OFF LED, MANUAL LED, and
MEMORY LED will light.
3. If a problem is found, the LEDs will indicate the problem as follows.
ON/OFF LED blinking: EEPROM error
MANUAL LED blinking: DSP(PRAM) error
MEMORY LED blinking: DSP(IRAM) error
If a problem is found, the unit will remain in this state, and it will not be
possible to carry out the remaining tests.
2. Switching noise / shock noise check
1. With the EFFECT ON/OFF LED, MANUAL LED, and MEMORY LED lit,
connect a short plug (47kΩ) to INPUT, and a monitor speaker to OUTPUT.
2. Press the EFFECT ON/OFF switch several times, and verify that no
abnormal switching noise occurs.
3. Press the EFFECT ON/OFF switch to make the EFFECT ON/OFF LED
go dark (ANALOG BYPASS), and drop the unit from a height of
approximately 10 cm to subject it to physical shock. Verify that no
abnormal noise occurs.
4. Press the EFFECT ON/OFF switch to make the EFFECT ON/OFF LED
light (DSP THRU), and drop the unit from a height of approximately 10
cm to subject it to physical shock. Verify that no abnormal noise occurs.
3. Residual noise check
1. Connect a noise meter to the OUTPUT.
2. Press the EFFECT ON/OFF switch to make the EFFECT ON/OFF LED
light (DSP THRU), and measure the residual noise.
Verify that the value detected by the noise meter is below -73 dBm (IHF-A).
3. Press the EFFECT ON/OFF switch to make the EFFECT ON/OFF LED
go dark (BYPASS), and measure the residual noise.
Verify that the value detected by the noise meter is below -104 dBm (IHF-A).
4. SW and LED check
1. Press the VARIATION switch, and you will proceed to the switch and
LED check.
First verify that only the VARIATION LED is lit.
The other LEDs will be dark.
Press the switches in the following order, and verify that in a similar
way, only one LED at a time is lit.
2. Press the AMP CTRL switch, and verify that only the AMP CTRL LED is lit.
3. Press the MEMORY WRITE switch, and verify that only the EFFECT
ON/OFF LED is lit.
4. Press the MEMORY WRITE switch, and verify that only the MANUAL
LED is lit.
5. Press the MEMORY WRITE switch, and verify that only the MEMORY
LED is lit.
6. Press the MEMORY SELECT switch, and verify that only the MEMORY 1
LED is lit.
7. Press the MEMORY SELECT switch, and verify that only the MEMORY 2
LED is lit.
8. Press the MEMORY SELECT switch, and verify that only the MEMORY 3
LED is lit.
9. Press the MEMORY SELECT switch, and verify that only the MEMORY 4
LED is lit.
(It is not possible to proceed to other test items before you have finished
the above procedure.)
5. AMP control check
1. Connect the AMP CTRL jack to the channel switching jack of the guitar
amp.
2. Verify that the guitar amp channel is switched each time you press the
AMP CTRL SW.
6. VR check
1. Turn the DRIVE volume from MIN to MAX, and verify that the
MEMORY 1-4 LEDs are all dark when the volume is at MIN (the instant
you begin turning the volume), and light correspondingly as you turn the
volume, so that all LEDs are lit when you reach MAX.
(Each VR you operate here must be left at the MAX position so that you
will be able to proceed to the next test item.)
In the same way, perform this test in the following order for the other
VR’s.
2. BOTTOM volume
3. TONE volume
4. LEVEL volume
5. ATTACK SHAPE volume
6. HEAVY OCTAVE volume
7. With the TYPE volume turned all the way to the left, turn it toward the
right one click at a time, and verify that the LEDs change as follows.
(TABLE A)
dark lit
(TABLE A)
TYPE EFFECT MANUAL MEMORY VARI AMPCTRL MEM1 MEM2 MEM3 MEM4
0 (OD-2/OD-1)
1 (BD-2/DS-1)
2 (HM-2/MT-2)
3 (BOOST/LEAD)
4 (CRUNCH/STACK)
5 (METAL/LOUD)
6 (T-SCREAM/FULL-D)
7 (DST+/CENTA OD)
8 (GUV DS/P-RAT)
9 (R-MAN/MUFF FUZZ)
10 (FACE/OCT FUZZ)

15
OD-20(T)
7. DAC check
1. Set the TYPE volume to BD-2/DS-1.
2. Connect an oscilloscope to OUTPUT, and check the output waveform
(DSP oscillation).
fig.1
(200mV/div, 1msec)
3. Press MEMORY SELECT. The MEMORY 4 LED will go dark, and the
output signal will be muted. Verify that the signal is less than -67 dBm
(IHF-A).
4. Connect an oscilloscope to LINE OUT/PHONES, and check the L and R
output waveform (DSP oscillation).
fig.2
(200mV/div, 1msec)
5. Press MEMORY SELECT. The MEMORY 4 LED go dark, and the output
signal will be muted. Verify that the noise for L and R is less than -68 dBm
(IHF-A).
8. DSP thru check
1. Set the TYPE volume to HM-2/MT-2.
2. Connect an oscillator to INPUT, and input a 344 Hz, 50 mVp-p square
wave.
3. Connect an oscilloscope to OUTPUT, and check the output waveform.
fig.3
(500mV/div, 1msec)
9. Analog mute check
1. Set the TYPE volume to BOOST/LEAD.
2. Connect an oscillator to INPUT, and input a 344 Hz, 50 mVp-p sine wave.
3. Connect an oscilloscope to OUTPUT, and check the output waveform.
fig.4
(20mV/div, 1msec)
4. Press MEMORY SELECT. The MEMORY 4 LED will go dark, and the
output signal will be muted. Verify that its level is less than -77 dBm
(IHF-A).

Apr.2002 OD-20(T)
BLOCK DIAGRAM
fig.block
INPUT
DC IN
OUTPUT
AMP CTRL
LINEOUT/PHONES
IC2
CODEC
IC3
AMP
FET SW
Q2
Q8
FET SW
BUFFER
Q3
AMP,LPF
IC11
TR SW
Q4,Q5,Q7
IC6
CPU
RESET
IC7
IC5
DSP
COMPARATOR
IC10
Q10
FILTER
IC8
DC-DC CONVERTER
Q11,
EEPROM
IC4
BUFFER
Q1
PRE EMPHASIS
AF/AD
IC1
BUFFER
Q12
DE EMPHASIS
BATTERY CN4
TR SW TR SW
Q6Q9
-9V
CN3CN5
WIRING 10P
WIRING 15P
CN1
CN2
CN1
CN2
VR1,VR2,VR3,VR4
VR5,VR6,VR7
SW1,SW2,SW3
SW4,SW5,SW6
LED1,LED2,LED3,LED4
LED5,LED6,LED7,LED8
LED9,LED10,LED11,LED12
RIBON CABLE
PANEL BOARD
JACK BOARD
3pin +
A9
+
D3.3
JK1
1
2
3
JK2
1
2
3
JK4
1
2
3
JK3
1
2
3
JK5
2
1
3
X2
11.2896MHz
1 2
X1
8MHz
1 2
1
2
3
1 2
1 2
16 17

18
Apr.2002
CIRCUIT BOARD(JACK)
Circuit_Jack-1.eps
Circuit_Jack-2.eps

19
OD-20(T)
CIRCUIT BOARD(PANEL)
Circuit_Panel.eps

Apr.2002 OD-20(T)
CIRCUIT DIAGRAM(JACK)
fig.jack
GUITAR INPUT
DC IN
TO BATTERY
OUTPUT
AMP CTRL
148/40us
Pre-Emphasis
DC IN
td=48ms
PHONES/LINE
LED_POWER
LED_AMP_CTRL
CA3
CA3
LED_ON/OFF
LED_4
LED_4
LED_3
LED_MEMORY
LED_VARIATION
LED_MANUAL
LED_ON/OFF
LED_MANUAL
LED_MEMORY
LED_AMP_CTRL
LED_VARIATION
LED_3
CA4
CA4
LED_2
LED_2
P03
P04
LED_1
LED_1
VR_TONE
VR_ATTACK
VR_OCTAVE
VR_LEVEL
VR_BOTTOM
VR_TYPE
VR_DRIVE
CA1
CA0
CA1
CA2
CA0
CA2
SW_ON/OFF
SW_VARIATION
SW_ON/OFF
SW_AMP CTL
SW_WRITE
SW_MAN/MEM
SW_VARIATION
SW_MAN/MEM
SW_AMP CTL
SW_SELECT
SW_SELECT
SW_WRITE
P04
P03
+
+
D3.3
D
+
D3.3
A
+
D3.3
D
+
AA
+
+
D3.3
+
A
+
A
A
+
AA
+
+
D3.3
+ +
+
+
+
A A A
+
D
+
D3.3
D
D
+
D3.3
D
D
D
+
D3.3
D
D
+
D3.3
+
D3.3
D
+
D3.3
D
+
D3.3
+
D3.3
D
D
D
+
D3.3
D
D
+
D3.3
D
+
D3.3
A
D
D
+
D3.3
D
D
-
A
A
D
+
A A A
+
+
D3.3
D
D
+
D3.3
D
D
D
+
D3.3 +
D
DD
-
+
A
A
A
A
A
A
A
A
+
A
+
+
A
+
D3.3
D
+
D3.3
+
A
A
A
R1
10k
C1
0.47S
Q1
2SK880GR
3
1 2
L3
SLF7045T-151MR37-2(150uH)
IC8
S-8520E33MC-BJS-T2
ON/OFF
1
VIN
5
VSS
2
EXT 4
VOUT 3
D7
SS14
C76
100/16
CN3
11
22
33
RIBON CABLE 2mm 3P
1
12
23
3
D5
SS14
IC2 AK4552VT
LIN
2
SDTO 8
RIN
1
VD
5MCLK 11
BCLK 12
PDN 13
DEM1 7
VCOM
14
LRCK 10
VSS
3
SDTI 9
DEM0 6
VA
4
ROUT 16
LOUT 15 +
-
IC3B
M5218AFP
6
5
7
R25
12k
R34
12k
D4
1SS355
12
Q8
2SK879Y
3
12
Q10 2SC4116GR
1
23
C79
0.1
C51
0.1 C54
100/16
C52
100/16
C53
0.1
C77 0.1
C33
0.047
R45
100k
R5
1M
R6
1k
Q11 IRF7606
S
2D7
S
3
D5 G
4
S
1D8
D6
R23 15k
C12 270p
R36
15k
C22
270p
R29
1M
C4
10/16
Q2
2SK879Y
3
12
D1
1SS355
12
R27
1M
R21
47k
C17
0.047
R28
100k
R2
1M
R3
1M
R30
39k
R26 47k
C13 270p
R17
10k
C9
0.0022
C19
1/50
R4
470k Q3
2SC3324GR
1
2 3
C3
1/50
C2
1/50
C31
100/16
C32
0.1
R40
10k
R46
10k
C20
10/16
C21
0.1
R35
10k
R33
10k
+
-
IC1C
NJM2100M
84
C35
0.1
R49
10k
R50
10k
C42 0.1
C44 0.1
C46 0.1
C40 0.1
C38 0.1
C69
18p
X2
CX-49G 11.2896MHz
C67 0.068
C43 0.1
C45 0.1
C47 0.1
C36 0.1
R61
1k
C34 47/16
R54 33
R60
1M
IC5
TC220C120AF-006(MR3)
OSC 1
VSS
2
OSCSEL 3
VSS
4
XTO 5
XTI 6
VDD 7
DIVS0
8DIVS1
9
PLLBP
10
VSS
11 VSS 12
TESTP
13
VDD 14
VDD
15
PLLVAA
16
PLLRO
17
PLLLP
18
PLLAGS
19
PLLAGD
20
VSS
21
VSS
22
VDD 23 VDD 24
RST 25
VSS
26
CD7 27
CD6 28
CD5 29
CD4 30
VSS
31
TESTS
32
VDD 33
CD3 34
CD2 35
CD1 36
CD0 37
VDD 38
DRQ 39
INT0 40
INT1 41
DRST 42
VSS
43
CA4 44
CA3 45
CA2 46
CA1 47
CA0 48
VDD 49
RD 50
CS 51
VSS
52
WR 53
VSS
54
DIV
55
VDD 56
DA0
57
AD0
58
VDD 59
BCK
60
VSS
61
LRCK0
62
LRCK1
63
VDD 64
MCK
65
VSS
66
DA1
67
AD1
68
DA2
69
AD2
70
VSS
71
CTYPE 72
VDD 73
DA3
74
AD3
75
SYI 76
TESTB
77
TESTT
78
VDD 79
VSS
80
C64
0.1
X1
49US SMD1 8MHz
C70 22p
C68 22p
R51
100
C58 0.01 C57 0.01 C59 0.01 C60 0.01 C56 0.01 C55 0.01 C61 0.01
IC4
CAT24WC02J
A0 1
A1 2
A2 3
VSS
4SDA 5
SCL 6
WP
7
VCC
8
R18
27 (2W)
R37
10
C24
0.1
C23
10/16 C25
10/16
C26
0.1
C30
0.1
C29
1/50
JK1
HTJ-064-12D
1
2
3
C5
0.0022 C6 100p
C7
10/16
R16
47k
R8
47k
+
-
IC1A
NJM2100M
2
3
1
R12
10k
+
-
IC1B
NJM2100M
6
5
7
R20
150k(F)
R24
10k(F)
TP1 TH
1
TP2 TH
1
R53
47k
R52
47k
JK2
HTJ-064-12D
1
2
3
RIBON CABLE 2mm 3P
1
12
23
3
C8
10/16
C15
10/16
C16
10/16
Q5
2SA1298Y
1
3 2
R13
10k
Q4
2SA1586GR
1
3 2
R15
10k
R11
10k
R32
10k
C48
NFM4516P13C204F
JK6 DJ-0711-020
2
1
3
JK5 KM02009_B
2
1
3
R57
2.2k
Q7
2SC3265Y
1
2 3
R48
miniSMDC075
C10
10/16
C11
0.1
R14
10k
R19
10k
L2
SLF7032T-4R7M1R7-2 (4.7uH)
IC6 MN101C30A
LED3/D3/P83
57
LED2/D2/P82
58
LED1/D1/P81
59
LED0/D0/P80
60
AN0/PA0 62
AN1/PA1 63
AN2/PA2 64
AN3/PA3 1
AN4/PA4 2
AN5/PA5 3
AN6/PA6 4
AN7/PA7 5
VDD
7
OSC2 8
OSC1 9
VSS
10
P22/IRQ2
29 P23/IRQ3
30 P24/IRQ4
31
P67/A7
44
P27/RST 21
MMOD 13
LED7/D7/P87
53
LED6/D6/P86
54
LED5/D5/P85
55
LED4/D4/P84
56
P66/A6
43
P65/A5
42
P64/A4
41
P63/A3
40
P62/A2
39
P61/A1
38
P60/A0
37
P70/A8
45 P71/A9
46 P72/A10
47 P73/A11
48 P74/A12
49 P75/A13
50 P76/A14
51 P77/A15
52
P21/IRQ1/SENS
28
P20/IRQ0
27
VREF+ 6
VREF- 61
X1 11
X0 12
P50/WE
32 P51/RE
33 P52/CS
34 P53/A16
35 P54/A17
36
P14/TM4IO 26
P13/TM3IO 25
P11/TM1IO 23
P12/TM2IO 24
P10/TM0TO/RMOUT 22
P06/BUZZER/DK 20
P05/SBT1 19
P04/SBI1 18
P03/SBO1 17
P02/SBT0 16
P01/SBI0/RXD 15
P00/SBO0/TXD 14
C78
100/16
C14
10/16
C18
10/16
RA5 100
1 8
2 7
3 6
4 5
D6
1SS355
1 2
C72
0.01
R62
330
D9
N.I.U.
12
D8
02DZ5.1Y
12
RA6 100
1 8
2 7
3 6
4 5
R55
47k
R56
47k
CN2
A2001WR2-15P
1
12
23
34
45
56
67
78
89
910
10 11
11 12
12 13
13 14
14 15
15
RA4
47k
18 27 36 45
RA2 680
1 8
2 7
3 6
4 5
RA3 680
1 8
2 7
3 6
4 5
Q6
2SC4116GR
1
2 3
R41
47k
R44
1M
Q9
2SC4116GR
1
2 3
R31
47k
R47
47k
R58
10k
C80
0.001
R22
27 (2W)
JK4
HTJ-064-12I
1
2
3
CN4
53015-0210
11
22
C39 0.1
C41 0.1
C37 0.1
R10
100k
+
-
IC3A
M5218AFP
2
3
1
+
-
IC3C
M5218AFP
84
C84
0.1
R73 10k
R75
100k
R78
100k
R74
470k
+
-
IC10C
M5216FP
84
R77
10
C93
10/16
C65
10/16
C74 47/16
C63
10/16
+
-
IC10B
M5216FP
6
5
7
C75
0.1
+
-
IC10A
M5216FP
2
3
1
C71
22p
C66
0.1
C62
0.1
R79
10
C94
1/50
D10
1SS355
1 2
C91 1/50
DA3 1SS302
21
3
R76
10
C92
100/16
+
-IC11A
M5216FP
2
3
1
R82
100k
R83
100k
C95
0.0018
R65
330
R9
4.7k
+
-IC11B
M5216FP
6
5
7
R86
100k
R87
100k
C90
150p
R69
330
R67
100k
C87
0.22/50
C49 100/16 C50
0.1
C83
150p
C88
150p
C85
150p
R7
10k
JK3
HTJ-064-12D
1
2
3
C81
100/16
R81 10k
R80
10k
R66
4.7k
R84
10k
R85 10kC89
0.0018
C86
100/16
R64
68(1/2W)
R68
68(1/2W)
R72 680
+
-IC11C
M5216FP
84
D2
1SS352
D3
1SS294
R88 4.7k
R59 27k
CN1
A2001WR2-10P
1
12
23
34
45
56
67
78
89
910
10
R70
10k
C73
0.1
IC7
S-80930CLMC
OUT
1Cp 5
VDD
2
NC 4 VSS
3
IC12
N.I.U.(S-80130ALMC-JAP-T2)
DS 1
GND 2
NC 3
VDD
5
OUT
4
Q12
2SC3324GR
1
2 3
R100
10k
R101
10k
R102
100k
R103
100k
C100 N.I.U.
C101 N.I.U.
C102 N.I.U.
20 21

Apr.2002 OD-20(T)
CIRCUIT DIAGRAM(PANEL)
fig.panel-c
(50KB) (50KB) (50KB) (50KB)
EFFECT
ON/OFF MANUAL
(50KB) (50KB)
MEMORY VARIATION 1234
DRIVEBOTTOMTONELEVEL
ATTACK
OCTAVE TYPE
AMP
CTRL
EFFECT
ON/OFF MAN/MEM VARIATION AMP CTRL WRITE SELECT
(50KB 11click )
SHAPE
HEAVY
(CENTER CLICK )
+
D3.3
D
+
D3.3
D
+
D3.3 + D3.3 + D3.3 + D3.3 + D3.3 + D3.3
+
D3.3 + D3.3
D
+
D3.3
D D D D D D D
+
D3.3
VR2
RD901-40-125F-B54-0CD
1
2
3
VR4
RD901-40-125F-B54-00D
1
2
3
VR1
RD901-40-125F-B54-00D
1
2
3
VR3
RD901-40-125F-B54-00D
1
2
3
VR6
RD901-40-125F-B54-00D
1
2
3
VR5
RD901-40-125F-B54-00D
1
2
3
VR7
RD901-40-125F-B54-11D
1
2
3
LED12
L-113GDT
12
LED5
L-34HDSL
12
LED6
L-312LRD
12
LED8
L-34HDSL
12
LED9
L-34HDSL
12
LED10
L-34HDSL
12
LED11
L-34HDSL
12
LED3
L-34HDSL
12
LED4
L-34HDSL
12
LED7
L-312LRD
12
C1 N.I.U.
SW1
SKQKAH
1 2
SW2
SKQKAH
1 2
SW3
SKQKAB
1 2
SW4
SKQKAB
1 2
SW5
SKQKAB
1 2
SW6
SKQKAB
1 2
CN2
WIRRING 15P
11
22
33
44
55
66
77
88
99
10 10
11 11
12 12
13 13
14 14
15 15
CN1
WIRRING 10P
11
22
33
44
55
66
77
88
99
10 10
22 23