Korg A4 Guitar User manual

SERVICE MANUAL
CONTENTS
1. SPECIFICATIONS 1
2. STRUCTURAL DIAGRAM 3
3. BLOCK DIAGRAM 5
4. CIRCUIT DIAGRAM 6
5. P.C. BOARDS 7
6. HOWTO DISASSEMBLY 9
7. DIAGNOSTIC TEST 11
8. REFERENCE DATA 18
9. PARTS LIST 26

1. SPECIFICATIONS
FOR A4GTR
Internal Effects :COMPRESSOR, DISTORTION/OVERDRIVE, 3BAND EQ, PITCH/DELAY,
CHORUS/FLANGER, REVERB, AMP SIMULATION, NOISE REDUCTION
Programs :Preset; 30 programs
User programable’, 30 programs
Front panel :Volume; INPUT VOLUME, PARAMETER EDITORS, OUTPUT VOLUME
Keys/Switches; BANK UP SWITCH, WRITE KEY, USER/PRESET KEY,
BYPASS/TUNE SWITCH, EFCT/PROG SWITCHES, PROG/EDIT SWITCH,
MODE(Effect)SELECT KEYSCUP, DOWN)
Display; BANK/VALUE Display (8 segment LED x2)
Dot type LEDs; EFCT/PROG LEDs, MODE LEDs, Peak indicator
Rear panel :Power Switch, DC9V Jack, INPUT Terminal, OUTPUT Terminals
(L/MONO, R), PHONE Jack, VOLUME PEDAL Jack, EXTERNAL CONTROL
OUTPUT Terminals (1, 2), MIDI Terminals (MIDI IN, MIDI OUT)
Sampling Frequency.* 48 KHz
Dynamic Range :90dB or more(IHF~A, when bypassing)
TUNER :Measurement Range; A0-C7
Measurement Accuracy; ±0.5 cent.
Power Supply •DC9V
Power Consumption ;350mA
Maximum Input
Level/Impedance *. +7dBu/lMQ
Maximum Output
Level/Impedance :+7.5dBu/lkQ
Dimensions •498(W) x227.5(D) x48.7(H)mm
Weight :2.2kg
1

FOR A4BASS
Internal Effects :
Programs :
Front panel :
Rear panel :
Sampling Frequency:
Dynamic Range :
TUNER :
Power Supply :
Power Consumption :
Maximum Input
Level/Impedance :
Maximum Output
Level/ Impedance :
Dimensions :
Weight :
COMPRESSOR, DYNAMIC EXCITER, 6BAND EQ, SYNTH BASS, DELAY,
CHORUS/FLANGER, REVERB. NOISE REDUCTION
Preset; 30 programs
User programablej 30 programs
Volume; INPUT VOLUME, PARAMETER EDITORS, OUTPUT VOLUME
Keys/Switches; BANK UP SWITCH, WRITE KEY, USER/PRESET KEY,
BYPASS/TUNE SWITCH, EFCT/PROG SWITCHES, PROG/EDIT SWITCH,
MODE(Effect)SELECT KEYS(UP, DOWN)
Display; BANK/VALUE Display (8 segment LED x2)
Dot type LEDs; EFCT/PROG LEDs, MODE LEDs, Peak indicator
Power Switch, DC9V Jack, INPUT Terminal, OUTPUT Terminals
(L/M0N0, R), PHONE Jack, VOLUME PEDAL Jack, EXTERNAL CONTROL
OUTPUT Terminals (1, 2), MIDI Terminals (MIDI IN, MIDI OUT)
48 KHz
90dB or more( IHF-A, when bypassing)
Measurement Range; A0-C7
Measurement Accuracy; ±0.5 cent.
DC9V
350mA
+7dBu/lMQ
+7.5dBu/lkQ
498(W) x227.5(D) x48.7(H)mm
2.2kg
*Specifications, operations and appearrance are subject to change without notice.

2. STRUCTURAL DIAGRAM
PART NO
(§>
PART CODE
745060308
715260308
715230308
540019600
i
HHSjjB PART NAME PART CODE
iX-150G CASE ASSEMBLY (A4 CTR) 646043400
lX-150B CASE ASSEMBLY (A4 B) 646043500
2X— 150 CHASSIS 641034600
3X-150 PHONE JACK SUPPORT 641034500
4X-150G PARAMETER SHEET (A4 GTR) 630018500
4X-150B PARAMETER SHEET (A4 B) 630018600
5ROTARY VR KNOB 620022900
6X-150 CORD HOOK 646043000
7POWER SW KNOB 620018200
8RUBBER SPACER K0C-40577 500019600
9
10
RUBBER FOOT 3x22x3
NAME SEAL
500018300
11 X-507 GND SPRING 644003000
12 P.C.B. ASSEMBLY KLM-1597 (MAIN FOR A4G) 001159700
12 P.C.B. ASSEMBLY KLM-1597 (MAIN FOR A4B) 0011597P1
13 P.C.B. ASSEMBLY KLM-1598 (PANEL) 001159800
14 P.C.B. ASSEMBLY KLM-1599 (REGULATOR) 001159700

m
UPPER CASE ASSEMBLY
PART NO PART NAME PART CODE
1X-150G CASE 646042700
1X-150B CASE 646043100
X- 150 PEDAL 646042800
SW CUSHION KOC-F40427 500013100
PEDAL SPRING K0C-C40896 644006400
5X-150 REFLECTOR 646042900

INPUT
LEVEL
A/D LPF
DSP D/A OUTPUT
L/MONO
LEVEL IND.
CURCUIT
LEVEL
IND .
TUNE
TUNER
CIRCUIT
1^L-J-j j
{^
MUTE
CURCUIT
wDRAM OUTPUT
LEVEL
CPU
ROM 256Kbit
RAM 6Kbit
PHOTO
COUPLER
'n PHONI
*V MINI
MIDI OUT
VOL
PEDAL
EXT
CONTROL
SWITCH LED
—-H
mm tIv*
BANK/PROG
VALUE PARMETER
.
BLOCK
DIAGRAM

4. CIRCUIT DIAGRAM
KLM-1 597/98/99
INPUT
LOR *501- 8000
LOR 4302’ 8000
6

5. P.C. BOARDS

6. HOW TO DISASSEMBLY
1. Remove the case assembly
1) Remove 8pcs. of the rotary VR knobs on the upper case.
2) Remove 16 pcs. of the screws on the chassis.
[PLAX BBZMC 3x10 ]x16
3) Remove 2pcs. of the harnesses and remove the case assembly.