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NAD T 975 C/AH Service Manual

Manual is about: seven channel amplifier

Summary of T 975 C/AH

  • Page 1

    / $ 8 1 $ 0 ( &, 9 5( 6 / $ 8 1 $ 0 ( &, 9 5( 6 7 &$+ $%, / - 4 , ! 5 . ! - % #) 6 2% 3 ‹ 1$' 1$' (/(&7521,&6 ,17(51$7,21$/ 7252172 7 + $ & 5( ,) ,/ 3 0 $ /( 1 1 $ + & 1( 9( 6 7 + $ & 5(, ), / 3 0 $ /( 1 1 $ + & 1( 9( 6 6(9(1&+$11(/$03/,),(5.

  • Page 2: Contents

    Contents front panel/rear panel view 3 specifications 4 alignment procedure/alignment points 5-6 wiring diagram 7 schematic diagram 8-15 pcb layout 16-23 electrical parts list 24-37 exploded view 38 exploded view parts list 39 packing diagram 40 service safety precautions 1. Replacing the fuses caut...

  • Page 3

    7 ' $ 1 7 ' $ 1 0$,16 ,1 0$,16 ,1 0dqxidfwxuhg'dw h ' h )d e 6huldo 1r1r 'h 6hulh v &$87,2 1 $77(17,2 1 0,1,080 63($.(5 ,03('$1&( 0,1,080 ,03('$1&( '(6 +$87(6 3$ 5/(856 21( 3$ ,5 2+0 0,1 6 3($.(5 21( 3$ ,5 ( 2+0 0,1 6 3($.(5 )86( )86( 63($.(5 63($.(5 63($.(5 63($.(5 63($.(5 63($.(5 63($.(5 63($.(5 6...

  • Page 4: Specifications

    - 4 - specifications continuous average power 140 w (21.5 dbw) output into 8 ohms or 4 ohms (min. Power per channel, 20 hz – 20 khz, both channels driven, with no more than rated distortion) rated distortion 0.03% (thd 20 hz – 20 khz) clipping power 170 w(22.3 dbw) (maximum continuous power per chan...

  • Page 5

    Alignment procedure (t975) a. Thermal sense adjustment this adjustment should be always done when the t975 is in a cool condition. (that means the temperature inside the unit should be almost same as the ambient temperature.) connector p208b that connects the transformer and power board should be re...

  • Page 6

    For example; all 7 channels at 50w/4 ohms for 10 minutes or 5 minutes or even less (as long as the fan can starts turning). Turn off the signal but still keep the unit operating for 1 minute. Then run all 7 channels at 1khz, 0.25w at 4 ohms load, monitor the voltage at tp1 j201. Adjust rv201 to get ...

  • Page 7

    Agnd +62v +62v -62v -62v agnd agnd agnd isctrig ac off sen protect -68v +68v -18v +18v sc pnp sc npn agnd +62v +62v -62v -62v agnd agnd agnd isctrig ac off sen protect -68v +68v -18v +18v sc pnp sc npn agnd +62v +62v -62v -62v agnd agnd agnd isctrig ac off sen protect -68v +68v -18v +18v sc pnp sc n...

  • Page 8

    Input offset isctrig +62v sen 62v testpoint 5 +12v -12v +12v -12v +12v -12v -12v offset +62v sen isc 62v input tp5 sc npn sc pnp /1kv /1/2w /1% temp sen all polyester capacitors are 63v unless noted. All elec. Capacitors are 50v unless noted. All resistor are 1/6w rj13 unless noted. /1kv /1kv /1kv /...

  • Page 9

    +62v -62v +68v isctrig agnd sc npn output output ac off agnd -62v agnd ac off sc pnp -62v sen -18v -68v protect -68v +62v +18v offset protect isctrig tp2 sen offset agnd sc npn sc pnp agnd testpoint5 testpoint5 sen agnd agnd -18v -18v +68v tp1 tp2 tp1 +68v agnd +18v ac off -62v -68v -18v protect +62...

  • Page 10

    Sen5 sen3 sen1 sen2 sen3 sen7 fan1 fan1 sen6 sen4 sen5 prot3 -70v fan1 sen2 dgnd scled stby agnd4 fan2 sen5 +18v +70v isctrig_6 isctrig_7 isctrig_3 sen7 agnd4 -18v acoff agnd6 +8v sen3 -62v_3 agnd6 -62v_4 agnd4 fan3 sen6 scled isctrig_4 prot4 +8v dgnd dgnd prot7 isctrig_1 prot2 +62v_4 -62v_4 agnd4 d...

  • Page 11

    Prot1 +12vd s c le d stbyled +12vd p r o t2 p r o t3 p r o t4 p r o t1 p r o t5 p r o t6 p r o t7 prot3 prot2 prot4 +5vd prot6 prot5 scled prot7 dgnd stbyled green stbyled +5vd /1/2w ch2 led ch3 led ch4 led ch5 led ch6 led ch7 led ch1 led all polyester capacitors are 63v unless noted. All elec. Capa...

  • Page 12

    -62v_4 stby -62v_3 dgnd dgnd dgnd dgnd scp_4 +62v_3 scled +62v_4 +8v +8v dgnd scled scn_4 scp_3 scn_3 +62v_3 -62v_3 scp_4 -62v_4 +62v_4 stby scp_3 scn_4 scn_3 scn_3 scp_4 dgnd stby scp_3 +62v_3 +8v -62v_3 scled +62v_4 -62v_4 scn_4 /1% /1% /1% /1% /1% /1% /1% /1% /1% /1% /1% /1% /1/2w /1/2w /1/2w /1/...

  • Page 13

    7v w505 only for c version 0v w503&w504 only for ah version only used for c version only used for ah version neutral live from power supply board from main transformer to main transformer power switch board f1 (user accessible fuse) t975 120v/230v table w501&w505 230v 120v no insert insert t20al/250...

  • Page 14

    Agnd4 -62v_4 +62v_4 agnd4 +62v_4 agnd4 -62v_4 agnd4 prot6 dgnd stby dgnd prot3 scled prot4 prot7 scled prot5 +8v prot1 prot2 stby agnd +8v -68v +68v dgnd agnd acoff +18v fan2 -18v fan3 fan1 +8v agnd6 +62v_3 agnd6 -62v_3 agnd6 +62v_3 dgnd scled scn_3 scn_4 scp_4 +62v_3 scp_3 -62v_3 -62v_4 +62v_4 -68v...

  • Page 15

    Tp902 115deg thermal circuit breaker tp902 115deg thermal circuit breaker 1 2 j901 2pin2.54-c j901 2pin2.54-c 1 2 tp901 115deg thermal circuit breaker tp901 115deg thermal circuit breaker 1 2 tp904 115deg thermal circuit breaker tp904 115deg thermal circuit breaker 1 2 tp903 115deg thermal circuit b...

  • Page 16

    C1 g 1 j102 j101 rl101 rv 101 attention: t975 vm1.0 2006/05/18 utiliser un fusible de rechange de meme type! Q14 0 q13 9 r10f c125 r10e rv103 r 10t r 1 0 k r1e2 solder r10h q127 amp board - solder side continued protection against risk of fire replace only with same type fuse and rating! Caution: r1...

  • Page 17

    P202a p201a nad 2006/05/18 f203&f204 is t1.25al/250v c210 f203 t975 seven channel amplifier q207 prot5 c257 c256 r2a3 p205b sen 5 r2 a 2 c275 psu board - solder side hs214 d 224 g2g1 ac in gn d curre nt ac o u t br208 +5 v d re l a y ~ ~ c255 c227 c228 ic 206 c 280 r2 e 9 r 215 c281 r 214 c 262 r213...

  • Page 18

    Softclipping protect led board - solder side t975 softclipping protect led board 317 softclipping protect led board - component side 325 r348 331r346 c301 r3 1 7 r 324 r345 329 r301 301r315 r322 r302 r309 r303 303 p 301a soft cli ppi ng r350 p 302a 332 d 309 d3 1 0 r 344 330 r 316 315 309 r330 r331 ...

  • Page 19

    C401 r410 r406 r402 trig board - solder side trig board - component side vm1.0 2006/05/18 t975 softclipping trig board c403 p401b r403 r411 r407 d403 r401 r405 d401 r409 s402 r413 d404 r412 r408 c404 s401 r404 s401 401 c402 d402 1 - 19 - pcb layout.

  • Page 20

    P621b p 611b p 612b p 613b 1 p 604b 9 1 1 1 1 p 606b 9 9 p 605b 1 9 9 1 9 p 614b p 615b 1 9 p 607b 1 scled p 608b stby dgnd 1 8v 1 9 1 scn 4 62v 3 -62v 3 62v 4 -62v 4 scn 3 scp 3 p 618b scp 4 12 p622 1 2 9 fa n 2 dg nd 2 fa n 1 dg nd 9 p 616b p 617b 1 1 p 610b 9 1 9 p 609b 1 2 fa n 3 dg nd 9 9 1 p62...

  • Page 21

    T975 power led board power led board v m 1.0 200 6/05 /18 d701 p701a 1 - 21 - pcb layout.

  • Page 22

    T975 switch board switch board vm1.0 2006/05/18 1 p801a s801 1 - 22 - pcb layout.

  • Page 23

    Tp board t p 901 901 t9 7 5 tp b o a r d v m 1. 0 2 00 6 /0 5 /1 8 t p 902 t p 904 t p 903 - 23 - pcb layout.

  • Page 24

    Electrical parts list designator description part type part number footprint ah p/n 01-97501-10 c p/n 01-97501-20 pcb1 board (amp) - 24 - diode d101 switch diode 1n4148 33-44148-00 dax/.300x.080/.031 d102 switch diode 1n4148 33-44148-00 dax/.300x.080/.031 d108 switch diode 1n4148 33-44148-00 dax/.30...

  • Page 25

    Electrical parts list designator description part type part number footprint q157 transistor 2sc2240-gr 31-02240-00 to92/100/ecb q158 transistor 2sa970-gr 31-00970-00 to92/100/ecb q159 transistor 2sc2362 31-02362-00 to92/100/ecb q159 transistor 2sc2240-gr 31-02240-00 to92/100/ecb q160 transistor 2sc...

  • Page 26

    Electrical parts list designator description part type part number footprint r160 metal oxide film resistor 2.7Ω, 2w , 5% 07-30279-02 ax/.800x.200/.037 r167 metal film resistor 220kΩ, 1/6w , 5% 07-20224-50 ax/.200x.080/.031 r168 metal film resistor 100kΩ, 1/6w , 5% 07-20104-50 ax/.200x.080/.031 r170...

  • Page 27

    Electrical parts list designator description part type part number footprint r10v metal film resistor 100kΩ, 1/6w , 5% 07-20104-50 ax/.200x.080/.031 capactior c102 polyester capacitor 100nf, 10%, 63v 25-10461-00 rad/.300x.150/ls.200/.035 c103 alu electrolytic capacitor 100uf/25v, 20%, 105 06-10121-0...

  • Page 28

    Electrical parts list designator description part type part number footprint l101 inductor 0.7uh, horizontal type 08-01079-01 rad/.850x.450/ls.700/.059 relay rl101 relays jqx-115f/024/1hs1 12-03101-03 relay_1 pot rv101 pot 5k, rk09k1110482-5ka 09-01502-00 vpot1 rv102 semi pot 300Ω, vertical type 09-...

  • Page 29

    Electrical parts list designator description part type part number footprint br206 bridge kbj2506 33-32562-00 bridge/1.180x.180/.087 br207 bridge kbj2506 33-32562-00 bridge/1.180x.180/.087 br208 bridge db104g 33-30142-00 bridge/.400x.500/.051 transistor q201 transistor ksa1220aystu 31-01220-00 to126...

  • Page 30

    Electrical parts list designator description part type part number footprint r214 metal film resistor 1k8Ω, 1/6w , 5% 07-20182-50 ax/.200x.080/.031 r215 metal film resistor 1k8Ω, 1/6w , 5% 07-20182-50 ax/.200x.080/.031 r216 metal film resistor 1k8Ω, 1/6w , 5% 07-20182-50 ax/.200x.080/.031 r217 metal...

  • Page 31

    Electrical parts list designator description part type part number footprint r284 metal film resistor 10kΩ, 1/6w , 5% 07-20103-50 ax/.200x.080/.031 r285 metal film resistor 10kΩ, 1/6w , 5% 07-20103-50 ax/.200x.080/.031 r286 metal film resistor 10kΩ, 1/6w , 5% 07-20103-50 ax/.200x.080/.031 r287 metal...

  • Page 32

    Electrical parts list designator description part type part number footprint c223 polyester capacitor 10nf, 10%, 250v 25-10322-01 rad/.300x.150/ls.200/.036 c224 alu electrolytic capacitor 1000uf/80v, 20%, 105 06-10281-01 cpcyl1/d.900/ls.400/.062 c225 alu electrolytic capacitor 1000uf/80v, 20%, 105 0...

  • Page 33

    Electrical parts list designator description part type part number footprint p205b connector molex 52807 right angle/non-zif/top contact style/16pin fpc1.0-16p) 13-21016-02 blkcon.100/vh/tm2sqb/w .300/1 6 p206b housing 12pin2.0-c 13-22012-00 blkcon.100/vh/tm1sq/w .200/12 p207a connector ribbon 6p2.0...

  • Page 34

    Electrical parts list designator description part type part number footprint q316 transistor 2sc1815-gr 31-01815-00 to92/100/ecb q317 transistor 2sc1815-gr 31-01815-00 to92/100/ecb q318 transistor 2sc1815-gr 31-01815-00 to92/100/ecb q319 transistor 2sc1815-gr 31-01815-00 to92/100/ecb q320 transistor...

  • Page 35

    Electrical parts list designator description part type part number footprint d401 zener diode 24v, 1/2w 33-12400-00 dax/.300x.080/.031 d402 zener diode 24v, 1/2w 33-12400-00 dax/.300x.080/.031 d403 zener diode 24v, 1/2w 33-12400-00 dax/.300x.080/.031 d404 zener diode 24v, 1/2w 33-12400-00 dax/.300x....

  • Page 36

    Electrical parts list designator description part type part number footprint p602b connector molex 52207 right angle/smt/zif/top contact style/16pin 13-21016-01 p603b connector s10b-ph-sm3-tb 13-22010-01 p604b connector molex 2145/3215 top entry/9pin 13-25009-00 p605b connector molex 2145/3215 top e...

  • Page 37

    Electrical parts list designator description part type part number footprint transformer 18-97132-01 connector connector ribbon one terminal:kst fdfd2- 187(8), another terminal kst fdfd2-250, wire:16aw g,double- insulated,white,300v,105c 1672 , l=600mm 14-97301-00 connector ribbon one terminal:kst f...

  • Page 38

    ) 6 ) 6 ) 6 6 6 35 ) 6 ) ) 3 6 & 6 3 6 3 6 6 & 6 & 6 & 6 6 6 & & & & 6 & & & $ 6 6 6 6 $ 6 $ $ $ $ $ 6 6 6 $ 6 $ $ & 6 6 6 6 5 5 6 5 6 5 5 6 6 5 75 75 6 75 75 6 7 6 & 6 6 3 3 3 3 3 3 3 6 3 6 6 6 6 ) ) ) ) 6 6 3 ) & & 6 & & 6 6 & & & & & 6 6 6 6 3 3 ) 6 & 6.

  • Page 39

    R e f .No p ar t no. De s c r ip tion qty. R e f .No p ar t no. De s c r ip tion qty. C 001 66-075002-0 c hassis 1 r 002 11-05202-10 s witch 1 c 002 66-010006-0 b racket1 1 r 003 11-05402-10 s witch 1 c 003 01-97506-00 c onnection b oard 1 r 004 13-22012-00 housing 1 c 004 66-010008-0 b racket3 2 r ...

  • Page 40

    - 40 - packing diagram.