Kenwood KAC-6202 Service manual

POWER AMPLIFIER

KAC-6202

SERVICE MANUAL

KAC-6202

(E type,M type)

Stereo/

Bridgeable

Powe

MAXIMUMPOWER

(K type)

Amplifie

Connecting cord assy (E30-6145-05)

Fuse (F52-0014-05)

Stereo/

Bridgeable

Powe

Amplifie

190mm

Accessory (W01-1607-05)

Screw set (N99-1587-05)

This product uses Lead Free solder.

KAC-6202

BLOCK DIAGRAM

RCA

LINE IN

SPEAKER IN

Rch

Lch

Rch

X09-590

+6dB

ISOLATION

AMP

6dB 6dB-27 0dB(LPF:+6dB) 26dB

INPUT OUTPUT

SW

ST/MONO

+6dB PHASE INVERT

HPF

LPF(+6dB)

HPF

MUTE

SW HPF/OFF/LPF

L

P. AMP

R

COMPONENTS DESCRIPTION

● AUDIO UNIT (X09-5900-10)

Ref. No. Application / Function Operation / Condition / Compatibility

IC1 Buffer amplifier +6dB, low-impedance conversion IC2 Isolation amplifier Common mode noise filtering IC3 Buffer amplifier +6dB,Rch reversal IC4 Reversal buffer amplifier +6dB, reversal amplifier IC5,6 HPF/LPF Fitter with variable cutoff IC7 DC/DC converter Oscillation and control of DC/DC converter Q1,2 Switching Transistor for ON/OFF control of latter step driver Q3~6 Drive transistor FET driver for the latter steps Q7,8 Switching FET Switching FET for the secondary power supply Q201,202 For muting Transistor for muting B-class step Q203~206 Differential amplifying transistor Transistor for first step differentiation amplification Q207~210 Differential amplifying transistor Transistor for second step differentiation amplification Q211,212 Current mirror load Current mirror load of second step differentiation Q213,214 Temperature compensating transistor For prevention of thermal-runaway of the final transistor Q215~218 Over current protection Transistor protection against excess current Q219~222 Power amplification First step of Darlington power amplification Q223~226 Power amplification Second step of Darlington power amplification Q501,502 Constant voltage stabilization Transistor for constant voltage stabilization Q601,602 Switching Transistor for mute ON/OFF control for B-class step Q603,604 Switching Transistor for mute control for B-class step Q605 Switching Transistor for DC protection circuit latch Q606 Switching For DC protection latch ON control Q607,608 Drive transistor For DC protection circuit driving

2

KAC-6202

COMPONENTS DESCRIPTION

Ref. No. Application / Function Operation / Condition / Compatibility

Q609 Switching For PULL-DOWN of DC/DC converter 2 pin Q610~614 Switching Transistor for power supply circuit ON/OFF control Q615 Switching Transistor for mute ON/OFF control for latter steps D1 Circuit protection diode For circuit protection at reverse connection of power supply cord D4~7 Switching Backflow prevention diode D8,9 Rectifying diode Rectification on the secondary power supply side D101~103 Static protection diode For circuit protection against static D201 Switching Backflow prevention diode D202,203 Operation stabilizer diode Contains thermal fluctuation of transistor Vbe of second step differentiation D204,205 Current mirror load Current mirror circuit load D206~211 Switching Backflow prevention diode D501 Indicator LED Indicator for behavior visual check D601 Bias diode Backflow prevention diode D602,606 Switching Backflow prevention diode D603 Level shifter For DC protection circuit bias D604 Switching For turning operation off at P-CON momentary power down D605 Switching For turning off operation at BATT excess voltage and for circuit protection D607 Level shifter For bias of the mute control circuit D608~612 Switching Backflow prevention diode

ADJUSTMENT

No. Item Alignment point Method Align for Note

1

IDLE VR3 (Lch) Connect a DC voltmeter

CURRENT VR4 (Rch) between emitter resister 5 minutes

Q223

R278

Q226

Lch 2.5mV

DC voltmeter

Q225

Q224

R277

VR3Lch

MIN MAX

VR4

Rch

2.5mV

Rch 2.5mV

DC voltmeter

After Power on

3

A B C D E

7

5

W

Q609

KAC-6202

1

PC BOARD (FOIL SIDE VIEW)

AUDIO UNIT X09-5900-10 (J76-0088-11)

R281

R282

C11

W208

C239C240

GND

W202 W203 W204

P1

L-OUT

GND

W207

P-CON

W201

SDG SDG

Q8

L1

TH1

D604

R621

Q612

BE

Q611

R624

W422

D605

C607

R622

D606

R623

R625

R636

BE

Q610

W421

GND

W205

W206

W199

GND

W197 W200

W198

R626

R627

D608

R628

C608

W419

W420

R630

D607

W418

R629

D603

R613 C613 R614

Q613

BE

R631

R638

Q605

C604

W188 W189

W190

W195 W196

W191

W192

W193

W194

BE

W417

BE

Q7

R632

Q614

W416

D602

R611

C602

2

D1

BATT-F

BATT

3

J3

4

R-OUT

1234 56 7

5

Q615

BE

R612

C609

W413

W149

R615

BE

W414

W415

Q607

BE

Q606

R280

C603

W187

C10

R633

BE

D9

D8

W186

W185

W184

W181

W183

W182

W179

W178 W177

W180

W170 W171 W172

W173 W174

L3

W175

W176

-B

GND

R24R25

C6

C5

W411

R634

D610

D609

R279

W209

Q608

R23

R22

THERMAL

R287

R21 R20

Q5

BE

R19

R18

BE

Q4

C4

W409

THERMAL

C8

W167 W168

Q226

BE

W410

GND

W165

BE

Q3 Q6

W407

R3

R8

W408

C3

W169

R10

R14

R26

R15

R7

W406

D6

W163

EB

Q2

BE

W403

BE

D7

Q1

W401

D4

W402

C9 R1

16 9

IC7

18

R11

R6 R4

W404

R2

W405

C12

C7

W161

W159 W160

W158

W162

W156

W164

W166

W157

R278

D5

R9 W400

+B

C1

C2

D211

W398

R275

W395

EB

Q222

Q223

W150

W152

W154

C236 C238

Q216

BEBE

D209

W155

W153

W145

W146

R268

R266 R284

W151

R272

BE

C606

Q218

R28

R274

W39

W148

R270

6

X09-5900-10

Ref. No. Address

IC1 3I IC2 3H IC3 4I IC4 4I IC5 5H IC6 5I

7

Refer to the schematic diagram for the values of resistors and capacitors.

IC7 3E

Q1 2D

Ref. No. Address

Q2 2D Q3 3D Q4 3D Q5 2D Q6 2D Q7 2C Q8 2B

Q201 4H

4