NAD S-300 Service manual

May 2007

NAD

SERVICE MANUAL

S 300

STEREO INTEGRATED

S 300

STEREO INTEGRATED

AMPLIFIER

AMPLIFIER

CONTENTS

FRONT PANEL / REAR PANEL VIEW................................... 3

SPECIFICATIONS................................................... 4

ALIGNMENT PROCEDURE / ALIGNMENT POINTS........................ 5

WIRING DIAGRAM.................................................. 6

PCB LAYOUT ................................................... 7-12

SCHEMATIC DIAGRAM............................................13-21

IC BLOCK DIAGRAM................................................22

ELECTRICAL PARTS LIST ......................................... 23-28

EXPLODED VIEW.................................................. 29

EXPLODED VIEW PARTS LIST ....................................... 30

PACKING DIAGRAM................................................ 31

SERVICE SAFETY PRECAUTIONS

1. Replacingthe Fuses

CAUTION:

WITH SAME TYPE OF FUSE.

REFERENCE NO. PART NUMBER DESCRIPTION

F1*AH 5100-2510-1C Fuse 250mA 250V Time Lag UL/CSA
F2*AH 5120-0061-0 Fuse 12A 250V Time Lag 6.3x32mm UL/CSA

F1*C 5120-0035-0 Fuse 100mA 250V Time Lag LBCVDE/SEMKO
F2*C 5120-0025-0 Fuse 6.3A 250V Time Lag HBCVDE/SEMKO

NOTE:

*AH : NorthAmerican model only
*C : European model only

2. Safety-checkout (NorthAmerican model only)

FOR CONTINUED PROTECTION AGAINST THE RISK OF FIRE REPLACE ONLY

Parts marked with the symbol are critical with regard to the risk of fire and electric shock.
Replace only withparts recommended by the manufacturer.

Before returning the product to the customer, make leakage current or resistance measurements
to determine that exposed parts are acceptably insulated from the supply circuit.

!

2

FRONT PANEL / REAR PANEL VIEW

FRONT PANEL CONTROLS

9

12

7

8

TAPE MONITOR TUNERIR CDAUX VIDEO

345

NA

Dual Mono Integrated Amplifier S300

6

D

1. POWER SWITCH 4. VOLUME CONTROL 7. TAPE MONITOR INDICATOR

2. INFRA-RED RECEIVER 5. INPUT SELECTOR 8. INFRA-RED INDICATOR

3. TAPE MONITOR 6. INPUT INDICATOR 9. POWER INDICATOR

The graphic symbol of a lightning flash with an arrow point
within a triangle signifies that there is dangerous voltage
within the unit and it posses a hazard to anyone removing
the cover to gain access to the interior of the unit. Only

qualified service personnel should make such attempt.

The graphic symbol of an exclamation point within
an equilateral triangle warns a user of the device
that it is necessary to refer to the instruction
manual and its warnings for proper operation of
the unit.

REAR PANEL CONNECTIONS

4

12

3

1. RIGHT BALANCED CD INPUT 6. LEFT TAPE INPUT/OUTPUT 11. AC INLET

2. RIGHT VIDEO INPUT 7. LEFT TUNER INPUT 12. LEFT SPEAKER OUTPUT

3. RIGHT AUX INPUT 8. LEFT AUX INPUT 13. GROUND TERMINAL

4. RIGHT TUNER INPUT 9. LEFT VIDEO INPUT 14. RIGHT SPEAKER OUTPUT

5. RIGHT TAPE INPUT/OUTPUT 10. LEFT BALANCED CD INPUT 15. NAD LINK INPUT/OUTPUT

5

131415

6789

12

10

11

3

SPECIFICATIONS

Measured in accordance with EIA Standard RS-490 (IHF-A-202) 1978.

Continuous average power output at 8 100W (20dBW)

(Minimum power per channel, 20Hz-20kHz,
both channels driven, with no more than rated distortion)

Input impedance Single ended 10K

Sensitivity 350mV

(for rated power into 8 )

W

W

Balanced 20K

W
W

Signal-to-Noise ratio (A-weighted) ref. 1W 88dB

Frequency response 20Hz - 20kHz +/-0.1dB

-3dB

DC - 250kHz

Gain tracking error +/-0.1 at maximum

+/-3dB at -60dB level

Damping factor >110

(ref. 8 , 50 Hz)

W

Physical specifications

Dimensions (WxHxD) 450x160 x400mm

Net weight 25.5 kg / 56.1 lbs

4

ALIGNMENT PROCEDURE

IDLE CURRENT ALIGNMENT (no load, no signal)

1. Connect a digital millivoltmeter between TP301 and TP303, and adjust P501 to
obtain a reading of between 30mV and 35mV.

2. Transfer the digital millivoltmeter to TP302 and TP304 and adjust P502 to obtain a
reading of between 30mV and 35mV.

3. Leave power on for at least 5 minutes to allow the idle currents to stabilize.
Re-adjust P501 and P502 as necessary to obtain a reading of between 30mV to
35mV on each channel.

ADJUSTMENT POINTS

LEFT POWER AMP PCB

TP303

TP301

RIGHT POWER AMP PCB

TP304

TP302

ALIGNMENT

TOOL

P501

P502

5

ALIGNMENT

TOOL

WIRING DIAGRAM

- LEFT +
SPEAKER

TERMINALS

BLACK

J531

RIGHT POWER

AMP BOARD

J517
J521
J515
J519
J525
J523

WHITE

BLUE

WHITE

BLACK

(X6)

J317
J321
J315
J319
J325
J323

J307

RED

BLACK

JK203

J303

+50V

J301

J313

NAD LINK BOARD

BLACK

RED

RED

JK205

JK207

J309

BLACK

SPK

GND L

RED

BLACK

JK209

J404

1

BLACK

RED

GRAY

J403

JK211

MAIN BOARD

J327

-50V

J401

25
26

GROUND TERMINAL

BLACK

RED

RED

SPK

GND R

BLACK

RED

BLACK

BLACK

J402

1

JK212 JK210 JK208 JK206 JK204

J328

-50V

1
2

BLACK

RED

J314

+50V

BLACK

J302

J310

RED

J304

J308

J318
J322
J316
J320
J326
J324

BLUE

WHITE

BLACK

(X6)

+ RIGHT -

SPEAKER

TERMINALS

BLUE

J532

LEFT POWER

AMP BOARD

J518
J522
J516
J520
J526
J524

BLACK

AC INLET

N

BLACK

J36

L

RED

BLACK

PRIMARY - 120V VERSION

WHITE

RED

J35

BLUE

J34

J33

RED

BLACK

J32

J31

J21 J22 J11 J12

YEL/GRN

GRAY

BROWN

TRANSFORMER - LEFT TRANSFORMER - RIGHT

ORANGE

ORANGE

PRIMARY - 230V VERSION

WHITE

J36

BLUE

J35

BLACK

J34

J33

RED

J32

BROWN

J31

J7

25
26

PRIMARY - 230V VERSION

BROWN

J42

J43

J41

1

POWER SUPPLY BOARD

2

FRONT PANEL BOARD

RED

BLACK

J44

BLUE

J45

WHITE

J46

J55

ORANGE

ORANGE

RED

J54

J53

GRAY

BROWN

J41

WHITE

J52

YEL/GRN

PRIMARY - 120V VERSION

RED

BLUE

BLACK

J42

J43

J44

J51

J45

WHITE

J46

J55

J54

WHITE

J53

RED

J52

J51

POWER SWITCH

J102

26
25

2

1

6