NAD T 175 User manual

NAD
SERVICE MANUAL
T 175
T 175
AV Tuner Pre-Amplifier
AV Tuner Pre-Amplifier
DRAFT DATE: MAY 2008

2
SAFETY INFORMATION
Manufactured under license under U.S. Patent #’s: 5,451,942; 5,956,674; 5,974,380;
5,978,762; 6,226,616; 6,487,535; 7,003,467; 7,212,872 & other U.S. and worldwide
patents issued & pending. DTS is a registered trademark & the DTS logos and Symbol
are trademarks of DTS, Inc. © 1996-2007 DTS, Inc. All Rights Reserved.
MODEL T 175 AV TUNER PREAMPLIFIER
POWER RATING 120V 60Hz 2A
NAD ELECTRONICS INTERNATIONAL
633 GRANITE COURT, PICKERING, ON, CANADA L1W 3K1
DESIGNED & ENGINEERED IN CANADA, CUSTOM
MANUFACTURED TO NAD SPECIFICATIONS IN CHINA
MODEL T 175 AV TUNER PREAMPLIFIER
POWER RATING 230V 50Hz 1A
NAD ELECTRONICS INTERNATIONAL
DESIGNED & ENGINEERED IN CANADA, CUSTOM
MANUFACTURED TO NAD SPECIFICATIONS IN CHINA

3
SERVICE SAFETY PRECAUTIONS
1. Replacing the fuses
CAUTION:
FOR CONTINUED PROTECTION AGAINST THE RISK OF FIRE REPLACE ONLY WITH SAME TYPE OF
FUSE.
Reference Designator Database Part Number Description
F8001*AH 20-001-0076-90 FUSE 1.6A 250V TIME LAG LBC
5x20mm TSD UL/CSA/VDE/SEMKO
F8001*C,CT 20-001-0066-90 Fuse TIME-LAG 1A/250VAC 5X20mm
TSD UL/CSA/VDE/CCC (WALTER)
F8002*AH 20-001-0066-90 Fuse TIME-LAG 1A/250VAC 5X20mm
TSD UL/CSA/VDE/CCC (WALTER)
F8002*C,CT 20-001-0068-90 FUSE TIME-LAG 500mA 250VAC
5X20mm TSD
UL/CSA/VDE/CCC WALTER
NOTE:
<*AH > : USA, CANADIAN MODEL ONLY.
<*C, *CT > : 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 supply circuit.
Parts marked with the symbol are critical with regard to the risk of fire and electric shock.
CONTENTS
DESCRIPTION PAGE
SPECIFICATIONS..............................................................................................................................4 - 6
REAR PANEL / FRONT PANEL VIEW ...................................................................................................7
DISASSEMBLY INSTRUCTIONS ...........................................................................................................8
WIRING DIAGRAM ..........................................................................................................................9 - 10
BLOCK DIAGRAM.................................................................................................................................11
SPECIAL FUNCTION ...........................................................................................................................12
DETAILS & WAVEFORMS ON SYSTEM & TEST & DEBUGGING................................................13-16
PCB LAYOUT..................................................................................................................................17- 34
SCHEMATIC DIAGRAM...................................................................................................................35-53
ELECTRICAL PARTS LIST..............................................................................................................54-72
IC BLOCK DIAGRAM.......................................................................................................................73-96
EXPLODED VIEW.................................................................................................................................97
EXPLODED VIEW PARTS LIST ....................................................................................................98-100
PACKING DIAGRAM...........................................................................................................................101

4
SPECIFICATIONS
PRE AMPLIFIER SECTION
Rated distortion (Ext 7.1 1kHz 500mV input ,Pre-out 1V with 30kHz LPF, FL/C/FR) ≤0.1 %
(Ext 7.1 1kHz 500mV input ,Pre-out 1V with 30kHz LPF, SL/SR/BL/BR) ≤0.1 %
S/N Ratio (Ext 7.1 1kHz 500mV input ,Pre-out 1V with A-WTD, 1kΩ termination, ≥- 85 dB
FL/C/FR/SL/SR/BL/BR)
Frequency Response (20 Hz - 20 kHz) 0±1.0 dB
Channel Balance (1 dB to -40 dB, 1 kHz) ≤2 dB
(-41 dB to -50 dB, 1 kHz) ≤3 dB
Audio muting at 1 kHz ≥55 dB
Subwoofer out, 500 mV in (THD at 2 V Pre-out, 100 Hz) ≤0.5 %
Crosstalk (500 mV input, ref @ 1V out, 1 kHz) ≥-60 dB
Controls
Bass (at 500 mV in, ref @ 1V out, 100 Hz) ±10 dB ±2 dB
Treble (at 500 mV in, ref @ 1V out, 100 Hz) ±10 dB ±2 dB
DOLBY DIGITAL SECTION
Channel Difference (FL ref. Track 30) ±1.2 dB
Frequency Resporse at Dolby config.2 SL Track 46 200 - 20 kHz ±0.8 dB
SR Track 47 200 - 20 kHz ±0.8 dB
C Track 44 200 - 20 kHz ±0.8 dB
Harmonic Distortion (1 V, Audio LPF, Dolby Config 1) FL Track 65 997 Hz ≤0.08 %
FR Track 67 997 Hz ≤0.08 %
SL Track 68 997 Hz ≤0.08 %
SR Track 69 997 Hz ≤0.08 %
C Track 66 997 Hz ≤0.08 %
S/N Ratio (31 for 100mV @ Pre-out, Track 35) CCIR / ARM ≥65 dB
Audio LPF ≥70 dB
A-wtd ≥70 dB
DOLBY PRO LOGIC II SECTION
Frequency Resporse
I/P mode : L, R : 1 V in, 1V @ Pre-out, Ch L/R 40 Hz 0±2.0 dB
20 kHz 0 ±2.0 dB
I/P mode : L=R : 1 V in, 1V @ Pre-out, Ch /L/R 40 Hz 0±2.0 dB
Ch C 20 kHz 0±2.0 dB
I/P mode : L=-R : 1 V in, 1V @ Pre-out, Ch SL/SR 40 Hz 0±2.0 dB
20 kHz 0±2.0 dB
S/N Ratio (200 mV in, 100mV @ Pre-out, A-WTD w/ 1 kΩ 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 (2.2 V in, 100mV @ Pre-out, w/ 80 kHz LPF, 1kHz) ≤0.2 %
MAX VOL PLII Music mode, 1kHz, 1Vp-p, CD in, ≥ 40 dB
NOISE connect to T775 Ext 7.1, measure at T775
Spk out, with ref. to 1W S/N (L,R,C,SL,SR)

5
DTS SECTION
Output Level (Vol 0 dB) : FL/FR/C/SL/SR Track 6 1 kHz 200 ±10mV
Channel Difference (FL ref) : FL/FR/C/SL/SR Track 6 1 kHz 0 ±1.5 dB
Harmonic Distortion (Audio Filter) : FL/FR/C/SL/SR Track 10-14 1 kHz ≤0.08 %
Frequency Response (20 Hz to 20 kHz) Track 26-30 +2/-1.5 dB
Subwoofer Output Level 1 kHz ref at pre-out (FL) Play Track 10, change to 15 12.5 ±1.5 dB
NOISE MEASUREMENT
Surround mode noise (Preout) DVD input 1V (L 20-20kHz -72dB
only), volume @ -12dB, Enhanced Stereo 1 mode, A-WTD -75dB
100mV Preout output reference
Surround mode noise (Subwoofer out) DVD input 1V 20-20kHz -75dB
(L only), volume @ -12dB, Enhanced Stereo 1 A-WTD -78dB
mode, 1V Preout output reference
Surround mode noise (Preout) DVD input 1V (L 20-20kHz -48dB
only), maximum volume, Enhanced Stereo 1 mode, A-WTD -50dB
100mV Preout output reference
Surround mode noise (Subwoofer out) DVD input 1V 20-20kHz -67dB
(L only), maximum volume @ -12dB, Enhanced A-WTD -72dB
Stereo 1 mode, 1V Preout output reference
AM TUNER SECTION
Input level is expressed as the reading in open circuit
of 75-ohm source impedance signal generator
Usable sensitivity (999/1000 kHz) ≤60 dBμV
S/N Ratio (5 mV in) ≥38 dB
THD (5 mV in) ≤3 %
IF Rejection (450 kHz) ≤36 dB
Image Rejection (F+2xIF) ≥28 dB
Selectivity ≥17 dB
Output 170 -20/+30 mV
Loop sensitivity (20 dB S/N)
999/1000 kHz ≤66 dB
603/600 kHz ≤66 dB
1404/1400 kHz ≤66 dB
Frequency Response (100 - 2.3 kHz, 5 mV) ±6 dB
FM TUNER SECTION *C *AH
Input level is expressed as the reading in open circuit
of 75-ohm source impedance signal generator
Usable sensitivity (98 MHz) ≤15 dBμ≤15 dBμv
S/N Ratio (60 dB, IHF wtd) Mono ≥60 dB ≥60 dB
Stereo ≥63 dB ≥63 dB
Frequency Response (20 Hz - 15 kHz, 60 dBμ) 0 ±1.5 dB 0 ±1.5 dB
Channel Separation (60 dBμ) 100 Hz ≥30 dB ≥30 dB
1k ≥32 dB ≥32 dB
10 kHz ≥30 dB ≥30 dB
Alternate Channel Selectivity (40 dBμ, ±400 kHz) ≥60 dB ≥45 dB
Capture Ratio (40 dBμ) ≤3 dB ≤3 dB
AM Suppression (60 dBμ, 100% Mod. FM, 30% Mod. AM) ≥48 dB ≥48 dB
Image Rejection (119.4 MHz) − ≥65 dB

6
I.F. Rejection (10.7 MHz) ≥78 dB −
Pilot Suppression (98 MHz) ≥50 dB ≥50 dB
THD (60 dBμ, L=R 75 kHz for AH, 40 kHz Dev for C) Mono ≤0.5 % ≤0.5 %
Stereo ≤0.5 % ≤0.5 %
Auto-Search Sensitivity On ≥24 dBμ≥24 dBμ
Off ≤15 dBμ≤15 dBμ
RDS decode Sensitivity ≤26 dBμ−
PHYSICAL SPECIFICATIONS
Dimensions (Width x Height x Depth) 435 x 134 x 353 mm
Net Weight 9.45 Kg (20.79 lbs)
Shipping Weight 13.9 Kg (30.58 lbs)

7
FRONT PANEL
REAR PANEL / FRONT PANEL VIEW
REAR PANEL
1. 7.1 CH INPUT
2. AUDIO PREOUT
3. MP DOCK
4. FM,AM ANTENNA INPUT
5. XM MODULE INPUT(AH)
DAB MODULE INOUT(C,CT)
6. RS-232
1. POWER BUTTON
2. STANDBY LED
3. INFO
4. AM/FM/DB
5. TUNER MODE
6. MEMORY
7. NAVIGATION AND
ENTER BUTTON
8. VACUUM, FLUORES
CENT DISPLAY(VFD)
9. REMOTE SENSOR
10. VOLUME
11. SOURCE
12. LISTENING MODE
13. TONE CONTROLS
14. TONE DEFEAT
15. FRONT INPUT/MP
16. PHONES
17. FRONT INPUT JACKS
18. MP/MIC INPUT
7. +12V TRIGGER OUT
8. IR IN/OUT
9. AUDIO/VIDEO 1~6 IN
10. MONITOR(S-VIDEO,VIDEO)
11. AUDIO/VIDEO 3/4 OUT
12. ZONE 2,3,4
13. HDMI
14. DIGITAL AUDIO IN/OUT
15. COMPONENT IN/OUT
16. AC POWER INLET
17. SWITCHED AC OUTLET
18. POWER

8
DISASSEMBLY INSTRUCTIONS
1. Remove machine screws M4.0 x 8.0 (x6pcs) from the side panels.
Remove tapping screw 3.0 x 8.0 (x 4pcs) from the back panel.
Refer to Figure No. 1.
2. Pull both sides of the TOP COVER slightly outwards and tilt approx. 35 ° and then
remove in the direction as indicated. Refer to Figure No. 2.
Figure No. 1
Figure No. 2

9
WIRING DIAGRAM

10
WIRING DIAGRAM PARTS LIST
Item Database Part Number Description Remark
1 17-012-3970-90 CABLE ASSY 4 WAYS AWG26 2.5P UL2468 PSU-J8002A
L=600mm (RoHS)
2 17-012-3966-90 CABLE ASSY 1 WAY AWG18 UL1672 BLUE PSU-J8011
L=120mm FASTON 4.8mm (RoHS)
3 17-012-3967-90 CABLE ASSY 1 WAY AWG18 UL1672 BROWN PSU-J8012
L=100mm FASTON 4.8mm (RoHS)
4 17-012-3940-90 CABLE ASSY 3 WAYS #26 2.5P UL2854 L=110 VOL BD-
(ROHS) J6004A/B
5 17-012-3999-90 CABLE ASSY 1 WAY AWG18 UL1007 L=100MM VOL BD-J6103A
W/ HEADER (RoHS)
6 17-012-4000-90 CABLE ASSY 2 WAYS AWG18 UL1007 3.96P VOL BD-
L=340MM (RoHS) J1002B/J6102A
7 17-012-3938-90 CABLE ASSY 1 WAY AWG18 UL1007 L=320MM DSP BD-J1002A
W/ HEADER (RoHS)
8 17-012-3971-90 CABLE ASSY 20 WAYS AWG28 UL2651 L=120mm KEY BD-J2002B
PCB MOUNT (RoHS)
9 17-012-3171-90 CABLE ASSY 6 WAYS AWG26 2.5P UL1533 L=160mm V6 BD-J2006B
(RoHS)
10 17-012-3404-90 CABLE ASSY 6 WAYS AWG26 2.5P UL1007 L=150mm V6 BD-J2005B
(RoHS)
11 17-012-3936-90 CABLE ASSY 3 WAYS AWG26 2.5P UL2854 L=310 CONN#1-J9006A
(RoHS)
12 17-012-3937-90 CABLE ASSY 5 WAYS AWG26 2.5P UL2854/1533 CONN#1-
L=230/320 (RoHS) J9004A/J9005A
13 17-012-3964-90 CABLE ASSY 3 WAYS AWG26 2.5P UL2854 L=230 CONN#1-
(RoHS) J9008A/B
14 17-012-2924-90 CABLE ASSY 1 WAY AWG18 UL1015 BLACK MCU BD-
L=260MM W/ RING TERMIMAL (RoHS) JP2004A
15 17-012-3930-90 CABLE ASSY 4 WAYS AWG26 2.5P UL1533 L=160mm MCU VD-J2008A
(RoHS)
16 17-010-0122-90 FFC CABLE 17 PINS P1.25 L=360MM 15 & 16 PINS TUNER-J6003A
VOID (RoHS)
17 17-012-2875-90 Cable assy 1 way AWG=16 UL 1015 Green/Yellow CHASSIS GND,
L=100mm(RoHS) AC OUTLET
GND
18 17-012-3938-90 CABLE ASSY 1 WAY AWG18 UL1007 L=320MM TUNER-J9104A
W/ HEADER (RoHS)
19 17-012-3965-90 CABLE ASSY 3 WAYS AWG26 2.5P UL2547 L=500 TUNER-J2016A
(RoHS)
20 17-012-3968-90 CABLE ASSY 1 WAY AWG18 UL1672 BLUE L=80mm J8015, J8017
(RoHS)
21 17-012-3969-90 CABLE ASSY 1 WAY AWG18 UL1672 BROWN L=80mm J8013, J8016
(RoHS)
22 17-012-3972-90 CABLE ASSY 26 WAYS AWG28 UL2651 L=450mm J2301C
(RoHS)
23 17-012-4001-90 CABLE ASSY 1 WAY AWG18 UL1007 L=420 TUNER-
W/ HEADER (RoHS) J9101A,J9102A

11
BLOCK DIAGRAM

12
SPECIAL FUNCTION
Function Keys Notes
Factory Reset AH Source Down + Front/MP
Factory Reset C Source UP + Front/MP
Toggle IR Channel Source Down + Power Only for v1.08 or higher.
Check MCU Version Source Down + Source UP For v1.03 or higher, this checks all versions.
Check DSP Version Source Down + Listening Mode Only for v1.02 or older.
Check Current Video Mode Source Down + Tone Controls
MIC Test Source Down + Tone Defeat
VFD Test Source Down + Display
PAL/NTSC Source Down + Memory
DAB/XM Source Down + Tuner Band Must cycle power before change takes effect.
9k/10k Source UP + Tuner Band Must reselect AM before change takes effect.
XM 1kHz Test Tone Tuner Band + Tuner Mode XM must be selected first.
XM Signal Strength Tuner Mode for 0.5 seconds XM must be selected first.
XM Diagnostics Mode Tuner Mode for 3 seconds XM must be selected first.
Check DAB Module Version Tuner Mode for 3 seconds DAB must be selected first.
Enter Diagnostics Mode Source Down + Enter
Diagnostic Mode Down Source Down + Cursor Right
Diagnostic Mode Up Source Down + Cursor Left
Power Off All Zones Power Toggle or Power Off for 3 seconds

13
DETAILS & WAVEFORMS ON SYSTEM TEST & DEBUGGING
DSP
U1007 Pin 70 - Clock for external memory,
100MHz
U1007 Pin 17 - X1001C output, 24.576MHz
U1007 Pin 2 - Master clock (Analog), 12.288MHz U1007 Pin 2 - Master clock (PCM), 11.2896MHz
U1007 Pin 12 – Left/Right clock (Analog), 48kHz U1007 Pin 12 - Left/Right clock (PCM), 44.1kHz

14
U1007 Pin 9 - Serial clock (Analog), 3.072MHz
MCU
U2001 Pin 12 - X2001A output, 20.000MHz
HDMI
U12 Pin 38 – U3 output, 28.636MHz

15
U9 Pin 1 –DAC_HS (OSD Off), 31.48kHz U9 Pin 54 –DAC_VS (OSD On, NTSC), 60Hz
U9 Pin 1 –DAC_HS (OSD On), 15.72kHz U9 Pin 54 –DAC_VS (OSD On, PAL), 50Hz
U9 Pin 54 –DAC_VS (OSD Off), 60Hz U9 Pin 4 –DAC_FLD (OSD Off), Idle

16
U9 Pin 4 –DAC_FLD (OSD On, NTSC), 30Hz U9 Pin 51 –PCLK (OSD On), 27MHz
U9 Pin 4 –DAC_FLD (OSD On, PAL), 25Hz
U9 Pin 51 –PCLK (OSD Off), 27MHz

17
PCB LAYOUT
DSP BOARD - COPPER SIDE

18
DSP BOARD - COMPONENT SIDE

19
KEY BOARD - COMPONENT SIDE KEY BOARD - COPPER SIDE

20
PRE-OUT BOARD- COPPER SIDE