NAD
T 742
SURROUND
SOUND RECEIVER
T
742
SURROUND SOUND
RECEIVER
SER
VICE
MANUAL
2
SERVICE SAFETY PRECAUTIONS
1.
Replacing the fuses
CAUTION: FOR CONTINUED PROTECTION AGAINST THE RISK OF FIRE REPLACE ONLY
WITH SAME TYPE OF FUSE.
Reference No
Part Number
Description
M270
*AH
5120-0200-0
5A TIME-LAG 5x20 UL/CSA
M271
*C
5120-0024-0
3.15A TIME-LAG 5x20 VDE-SEMKO
M272
*AH
5120-0052-0
1.6A TIME-LAG 5x20 UL/CSA
NOTE:
<*AH > : USA, CANADIAN MODEL ONLY.
<*C > : EUROPEAN MODEL ONLY.
2.
Safety check out
(Only U.S.A. model)
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.
Parts marked with the symbol
are critical with regard to the risk of fire and electric shock.
Replace only with parts recommended by the manufacturer.
CONTENTS
DESCRIPTION
PAGE
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3-4
REAR PANEL / FRONT PANEL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5
DISASSEMBLY INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6
WIRING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-8
BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
ADJUSTMENT POINTS DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10-11
INSTRUMENT SETUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
ALIGNMENT PROCEDURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12-13
IMPORTANT NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14-24
SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25-42
IC BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43-51
ELECTRICAL PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52-71
EXPLODED VIEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .72
EXPLODED VIEW PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73-74
PACKING DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
3
SPECIFICATIONS
POWER AMPLIFIER AND PREAMPLIFIER SECTION (all channels stated 8 ohms)
Rated distortion
(THD 20Hz-20 kHz FL/C/FR)
0.08%
(THD 20Hz-20 kHz SL/SR)
0.3%
Input Sensitivity
(ref. 8 ohms, 1 kHz)
180+/-30 mV
S/N Ratio
(A-wtd, 1KHz, 1W, 8 ohm)
-78 dB
(A-wtd, 1KHz, 80W, 8 ohm)
FL/FR/C
92 dB
SL/SR
-90 dB
Frequency Response
(20 Hz - 20 kHz)
0 ± 0.8 dB
Channel Balance
(1 dB to -40 dB, 1 kHz)
2 dB
(-41 dB to -50 dB, 1 kHz)
3 dB
Audio muting at 1kHz
53 dB
Headphone O/P in 0.1%, 600 ohm load, CD in 500mV, 1 kHz
10V
Subwoofer out, 500mV in
(THD at 2V O/P, 100 Hz)
0.5%
(S/N at 2V O/P, 100 Hz)
80 dB
Crosstalk
(2V input, 10W, 1 kHz)
> -68 dB
Continuous average power output (L/R/C RL/RR 8 ohms)
50 W
Controls
Bass
(at 500mV in, 1W out, 100 Hz)
±9 dB
Treble
(at 500mV in, 1W out, 10 kHz)
±9 dB
SURROUND SECTION
Channel separation
I/p mode : L, R
: 1V in, 1 kHz, Ch R, L
45 dB
: o/p at unexpected, 1 kHz, Ch C
35 dB
I/p mode : L= -R
: 1V in, 1 kHz, Ch R, L
28 dB
: o/p at unexpected, 1 kHz, Ch C
30 dB
I/p mode : L= R
: 1V in, 1 kHz, Ch R, L
45 dB
: o/p at unexpected, 1 kHz, Ch SL, SR
30 dB
Frequency Response
I/p mode : L, R
: 1V in, 1W, Ch R, L
40Hz
0 ± 1.5 dB
20kHz
0 ± 1.5 dB
I/p mode : L= R
: 1V in, 1W, Ch C
300Hz
0 ± 0.8 dB
20kHz
0 ± 0.8 dB
I/p mode : L= -R
: 1V in, 1W, Ch SL, SR
30Hz
0 ± 1.0 dB
6.5kHz
-3 ± 1.0 dB
S/N Ratio ( 200mV in, 1, A-WTD w/ 1k termination)
I/p mode : L, R
: 1 kHz, Ch L, R
65 dB
I/p mode : L=R
: 1 kHz, Ch C
65 dB
I/p mode : L=-R
: 1 kHz, Ch SL, SR
65 dB
THD (2.2V in, 1W, w/ 80 kHz LPF, 1 kHz)
0.2%
DTS SECTION
Frequency Response
FL, FR, C, SL, SR:
200Hz
0 ± 0.8 dB
20kHz
0 ± 0.8 dB
Distortion 1W all channels
0.08%
4
AM TUNER SECTION
Input level is expressed as the reading in open-circuit
of 75-ohm source impedance signal generator
Usable sensitivity (999/1000kHz)
30 dBµ
S/N Ratio (5mV in)
38 dB
THD (5mV in)
3%
IF Rejection (450 kHz)
45 dB
Image Rejection (F+2xIF)
28 dB
Selectivity
17 dB
Output
130+/- 20mV
Loop sensitivity (20dB S/N)
999/1000 kHz
66 dB
603/600 kHz
66 dB
1404/1400 kHz
66 dB
Frequency response (100 - 2.3 kHz, 5mV)
± 6 dB
FM TUNER SECTION
*C
Input level is expressed as the reading in open-circuit
of 75-ohm source impedance signal generator
Usable Sensitivity ( 98 MHz)
15 dBµ
Signal / Noise Ratio
Mono
72 dB
(60 dBµ, IHF wtd)
Stereo
66 dB
Frequency Response (20 Hz - 15 kHz, 60 dBµ)
0 ± 1.5 dB
Channel Separation (60 dBµ)
100 Hz
30 dB
1 kHz
40 dB
10 kHz
30 dB
Alternate Channel Selectivity
(40 dBµ, ±400 kHz)
60 dB
Capture Ratio (40 dBµ)
3 dB
AM Suppression
(60 dBµ, 100% Mod.FM, 30% Mod.AM)
48 dB
Image Rejection (119.4 MHz)
68 db
I.F. Rejection ( 10.7 MHz)
78 dB
Pilot Suppression (60 dBµ)
60 dB
THD (60 dBµ, L=R 75 kHz for AH, 40 kHz Dev for C)
Mono
0.25%
Stereo
0.35%
Auto-Search Sensitivity
On
24 dBµ
Off
15 dBµ
RDS decode Sensitivity
26 dBµ
POWER RATING
EUROPEAN Model
*C
AC 230V~ 50Hz 1.2A
USA, CANADIAN Model
*AH
AC 120V~ 60Hz 2.5A
PHYSICAL SPECIFICATIONS
Dimensions (Width x Height x Depth)
435 x 131 x 348mm
Net weight
14kg (31 lbs)
Shipping weight
16.7kg (37 lbs)
5
REAR PANEL / FRONT PANEL
REAR PANEL
FRONT PANEL
1. FM & AM ANTENNA
2. TAPE 1 & CD INPUTS
3. 5.1 CHANNEL INPUTS
4. DVD - SAT VCR - VIDEO 4 (AUDIO &
VIDEO)
5. DIGITAL AUDIO INPUTS
6. AUDIO PRE OUTS / SUBWOOFER OUT
7. MONITOR OUT
8. SPEAKERS: FRONT, CENTER & SUR-
ROUND SPEAKERS
9. SOFT CLIPPING
10. IR INPUT
11. AC POWER CORD
12. 12 VOLT TRIGGER OUT
1. POWER
2. STAND-BY INDICATOR
3. DISPLAY
4. FM/AM
5. FM MUTE / MODE
6. MEMORY
7. PRESET / TUNE
8. DOWN / UP
AND
9. VFL DISPLAY
10. VOLUME & SETUP
11. HEADPHONE SOCKET & VIDEO 5 INPUT
12. AUDIO & VIDEO INPUT SELECTORS
13. CD
14. TAPE MONITOR
15. EXT. 5.1
16. SURROUND MODE
17. SET UP
18. TONE CONTROLS