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NAD M25 AH Service Manual

Manual is about: SEVEN CHANNEL AMPLIFIER

Summary of M25 AH

  • Page 1

    Ser vice m anual ser vice m anual m25 c/ah mo d el: m 3 se r v ic e m a n u a l © nad 2005 nad electronics international toronto m25 c/ah seven channel amplifier m25 c/ah seven channel amplifier seven channel amplifier.

  • Page 2: Contents

    Contents front panel/rear panel view 3 specifications 4 alignment procedure/alignment points 5-6 wiring diagram 7 schematic diagram 8-16 pcb layout 17-23 electrical parts list 24-40 exploded view 41-44 exploded view parts list 45 packing diagram 46 service safety precautions 1. Replacing the fuses c...

  • Page 3: Front Panel Controls

    Front panel / rear panel view front panel controls 1. Power switch 2. Power indicator 3. Soft clipping indicator 4. Protection indicator 1. Ac inlet 2. Input jack 3. Level control 4. Speaker terminals 5. Auto trigger switch 6. 12v trigger input 7. Soft clipping switch 8. Mains fuse 9. Ground termina...

  • Page 4: Specifications

    - 4 - specifications continuous average power 160 w (22.0 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 180 w (maximum continuous power per channel). Ihf ...

  • Page 5

    Alignment procedure a. Thermal sense adjustment this adjustment should be always done when the m25 is 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 removed to avoid...

  • Page 6

    For example, all 7 channels at 50w/4ohms 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 of pot rv201. Adjust rv201 ...

  • Page 7

    Agnd acin acin acout acout +5 v +5 v relay relay sc npn sc pnp +18v -18v +70v -70v protect sen ac off +62v -62v -62v agnd agnd agnd isc trig agnd +62v +18v -18v +70v -70v protect sen ac off sc npn sc pnp +62v -62v -62v agnd agnd agnd isc trig agnd +62v +18v -18v +70v -70v protect sen ac off sc npn s...

  • 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 protect -68v +62v +18v offset isctrig tp2 tp1 sen offset agnd sc npn sc pnp agnd tp5 tp5 sen agnd agnd -18v -18v protect protect protect protect +68v -68v +68v agnd +18v ac off -62v -68v -18v protect +...

  • Page 10

    Sen5 sen3 sen1 sen2 sen3 sen7 fan1 fan1 sen6 sen4 sen5 -70v fan1 fan2 +18v +70v agnd4 -18v acoff -62v_3 agnd6 -62v_4 agnd4 fan3 agnd1 +62v_4 -62v_4 agnd4 +62v_4 fan2 +62v_3 agnd6 fan3 fan3 agnd6 +62v_3 -62v_3 dgnd off1 off2 off3 off1 off2 off3 stby +62v_4 -70v -70v +70v +18v +18v stbyled +62v_3 +62v...

  • Page 11

    Prot6 stbyled prot5 prot4 prot4 prot5 prot2 scled prot3 prot3 prot1 +12vd sc l e d +12vd +5vd prot7 dgnd dgnd +5vd stbyled pr o t 1 pr o t 2 pr o t 3 pr o t 4 pr o t 5 pr o t 6 pr o t 7 all polyester capacitors are 63v unless noted. All elec. Capacitors are 50v unless noted. All resistor are 1/6w un...

  • 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 to power switch board from power supply board from main transformer to main transformer f1 (user accessible fuse) m25 120v/230v table w501&w505 230v 120v no insert insert t20al/2...

  • Page 14

    Agnd4 -62v_4 +62v_4 agnd4 +62v_4 agnd4 -62v_4 agnd4 +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 scn_3 +18v acoff -18v +68v prot5 sen5 scp_3 -68v scn_3 +18v acoff -18v +68v prot6 sen6 scp_3 -68v scn_3 +18v acoff -18v +68v prot7 sen7 s...

  • Page 15

    S801 sddlb1027u-rn s801 sddlb1027u-rn 1 2 p801a 2p2.54-a100b p801a 2p2.54-a100b 1 1 2 2 schematics diagram - 15 -.

  • Page 16

    120deg thermal autoreset switch red ul1015 14awg 300mm blk ul1015 14awg 300mm gry ul1015 14awg 300mm 0v 42.9v no load 41.1v/17.4a(voltage between pin8 to pin9) 57.4v no load 55.2v/13.5a(voltage between pin7 to pin9) 42.9v no load 41.1v/17.4a(voltage between pin9 to pin10) 57.4v no load 55.2v/13.5a(v...

  • Page 17

    J103 j104 j10 1 rv1 01 c1g1 rl101 g1g2 continued protection against risk of fire replace only w ith same type idling current r141 r139 q120 d105 c159 r142 r143 r1p2 r1n6 solder m25 poweramp module vm1.0 2005/08/08 q148 r1n2 r198 fuse and rating! D106 c132 r1a6 r130 r132 q114 q115 r176 d109 c117 r152...

  • Page 18

    P202a p201a designed by:hansong m25 team 2005/08/08 vm 1.0 f201&f202 are t1.6al/250v f203&f204 are t1.6al/250v c210 f203 br202 b hs214 hs205 e be nad m25 thx seven channel amplifier q208 q207 r296 c274 r2a2 r2a3 d215 hs206 d224 r2f3 g2 g1 ac in is e n dg nd 6 ac o u t p207a +5 v d re l a y br208 ~ 1...

  • Page 19

    P621b p 604b 1 9 1 1 1 p 606b 9 1 p 605b 9 1 p 612b 9 p 613b 9 1 p 611b 9 1 9 p 607b 1 1 1 9 p 608b p622 1 9 p 615b 2 2 p 614b 9 p623 1 1 p 610b 9 1 9 p 609b 1 2 p 616b 9 p 617b 9 1 vm1.0 2005/08/08 dg nd fa n 2 8 p619b 1 p620b 8 bus606 bus605 bus604 1 fa n 3 -68v + 68v ac o f f p603b + 18v -18v dg ...

  • Page 20

    Po w e r r 345 d308 d310 q 332 r 348 r 347 q 330 r343 p301a p301a q331r346 q329 r344 d307 q310 r331 q326 q319 r340 q313 d305 ch 6 q327 r334 r341 r306 r320 q320 q314 d306 ch 7 r335 q328 r342 r307 r321 q321 ch 3 q324 q311 r338 r332 d303 ch 4 q317 r304 r318 q325 r339 q312 d304 ch 5 r333 q318 r305 r319 ...

  • Page 21

    Vm1.0 2005/08/08 r401 r409 r405 c401 c402 1 r406 r410 d402 r402 m25 softclipping&trig board r412 r404 r408 j401 r413 s402 d404 p401b c404 c403 s401 r403 r407 r411 d403 d401 pcb layout trigger board - component side trigger board - solder side - 21 -.

  • Page 22

    S 801 1 1 v m 1. 0 2005/ 08/ 08 m25 s w itc h b oar d p 801a pcb layout sw board - component side sw board - solder side - 22 -.

  • Page 23

    Tr502 c501 w503 for ah version w501 only used w502 only used for c version r v 501 m 2 5 s t a ndby b oa r d vm 1.0 2005/08/08 p501b w5 01 p502b w 5 0 2 1 p505b rl501 tr501 w503&w504 only w504 for ah version d501 p503b for c version w505 only w505 p506b p504b pcb layout standby board - component sid...

  • Page 24

    Designator description part type part number footprint d100 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d101 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d102 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d103 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d104 switch diode 1n4...

  • Page 25

    Designator description part type part number footprint q119 transistor 2sa1015-gr 31-01015-00 to92/100/ecb q120 transistor 2sa970-gr 31-00970-00 to92/100/ecb q121 transistor 2sa970-gr 31-00970-00 to92/100/ecb q122 transistor 2sa970-gr 31-00970-00 to92/100/ecb q123 transistor 2sa1360-o 31-01360-00 to...

  • Page 26

    Designator description part type part number footprint r122 metal film resistor 100Ω, 1/6w, 5% 07-20101-00 ax/.200x.080/.031 r123 metal film resistor 100Ω, 1/6w, 5% 07-20101-00 ax/.200x.080/.031 r124 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r125 metal film resistor 1kΩ, 1/6w,...

  • Page 27

    Designator description part type part number footprint r180 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r181 metal film resistor 22kΩ, 1/6w, 5% 07-20223-00 ax/.200x.080/.031 r182 metal film resistor 3k3Ω, 1/6w, 1% 07-23301-00 ax/.200x.080/.031 r183 metal film resistor 220kΩ, 1/6...

  • Page 28

    Designator description part type part number footprint c106 ceramic capacitor 10pf, 5%, 1kv 05-10013-01 cpax/.200x.100/.031 c107 ceramic capacitor 15pf, 5%, 1kv 05-15013-01 cpax/.200x.100/.032 c108 polyester capacitor 10nf, 10%, 63v 25-10361-04 rad/.300x.150/ls.200/.031 c109 ceramic capacitor 22pf, ...

  • Page 29

    Designator description part type part number footprint c151 alu electrolytic capacitor 1uf/50v, 20%, 105 06-10951-03 cpcyl/d.200/ls.200/.031 c152 polyester capacitor 1nf, 5%, 63v 25-10261-00 rad/.300x.150/ls.200/.031 c153 ceramic capacitor 470pf, 10%, 1kv 05-47113-00 cpax/.200x.100/.038 c154 alu ele...

  • Page 30

    Designator description part type part number footprint d207 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d208 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d209 switch diode 1n4148 33-44148-02 dax/.300x.080/.031 d210 zener diode 8.2v, 1/2w 33-18209-01 dax/.300x.080/.031 d211 zener diode 8...

  • Page 31

    Designator description part type part number footprint q217 transistor 2sd667-awc 31-00667-00 to92/100/ecb q218 transistor ksc2690aystu 31-02690-00 to126/90/ecb q219 transistor ksc2690aystu 31-02690-00 to126/90/ecb q220 transistor ksc2690aystu 31-02690-00 to126/90/ecb q221 transistor 2sc1815-gr 31-0...

  • Page 32

    Designator description part type part number footprint r231 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r232 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r233 metal oxide film resistor 10kΩ, 1/2w, 5% 07-30103-00 ax/.400x.100/.031 r234 metal oxide film resisto...

  • Page 33

    Designator description part type part number footprint r285 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r286 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r287 metal film resistor 10kΩ, 1/6w, 5% 07-20103-00 ax/.200x.080/.031 r288 metal film resistor 10kΩ, 1/6w...

  • Page 34

    Designator description part type part number footprint c214 alu electrolytic capacitor 3300uf/35v, 20%, 105 06-33231-00 cpcyl1/d.900/ls.350/.062 c215 alu electrolytic capacitor 100uf/35v, 20%, 105 06-10131-05 cpcyl1/d.300/ls.200/.031 c216 alu electrolytic capacitor 100uf/35v, 20%, 105 06-10131-05 cp...

  • Page 35

    Designator description part type part number footprint c255 alu electrolytic capacitor 2200uf/25v, 20%, 105 06-22221-04 cpcyl1/d.900/ls.350/.062 c256 polyester capacitor 10nf, 10%, 100v 25-10312-01 rad/.300x.150/ls.200/.035 c257 polyester capacitor 100nf, 10%, 100v 25-10412-02 rad/.300x.150/ls.200/....

  • Page 36

    Designator description part type part number footprint f203 fuse t1.6al/250v 20-12162-01 t1.6al/250v f204 fuse t1.6al/250v 20-12162-01 t1.6al/250v w201 jumper 10mm 21-06101-00 10mm w202 jumper 10mm 21-06101-00 10mm w203 jumper 20mm 21-10201-00 20mm bus201 busbar 69-046003-0 bus202 busbar 69-046002-0...

  • Page 37

    Designator description part type part number footprint q328 transistor 2sa1015-gr 31-01015-00 to92/100/ecb q329 transistor 2sa1015-gr 31-01015-00 to92/100/ecb q330 transistor 2sc1815-gr 31-01815-00 to92/100/ecb q331 transistor 2sc1815-gr 31-01815-00 to92/100/ecb q332 transistor 2sa1015-gr 31-01015-0...

  • Page 38

    Designator description part type part number footprint p302a housing 1.0-11-16ps 13-21016-06 blkcon.079/vh/tm1sq/w.200/ 16 d401 zener diode 24v, 1/2w 33-12400-06 dax/.300x.080/.031 d402 zener diode 24v, 1/2w 33-12400-06 dax/.300x.080/.031 d403 zener diode 24v, 1/2w 33-12400-06 dax/.300x.080/.031 d40...

  • Page 39

    Designator description part type part number footprint rl501 relays 832a-1a-c-bh dc5v 12-03101-02 p501b jack pcfs250l 32-26304-10 p502b jack hs4-ci9120-b009v1-m032 32-26304-00 p503b housing 2pin2.54-c 13-22502-00 blkcon.100/vh/tm1sqb/w.200 /2 p504b housing 2pin3.96-c 13-23902-00 blkcon.156/vh/tm1sqb...

  • Page 40

    Designator description part type part number footprint bus605 bus-bar 69-010002-0 bus606 bus-bar 69-010002-0 s801 switch sddlb1027u-rn 11-01101-20 p801a connector 2p2.54-a150b 14-97302-11 xhb-2.5a-2y fan efb1212l 35-01212-00 fuse t20al/250v(ah) 20-11203-10 fuse t10al/250v (c) 20-12103-20 fuse holder...

  • Page 41

    A001 a002 a008 a003 a004 a005 a010 s004 s005 s007 s006 s008 s002 s003 a009 a006 a007 s001 exploded view - 41 -.

  • Page 42

    S009 tr01 tr03 tr02 tr04 tr05 s010 s011 s012 insulator exploded view - 42 -.

  • Page 43

    C001 c002 c003 c004 s007 c008 s013 s014 c009 s018 c010 c011 s007 c012 c005 s005 c006 c007 c011 s017 s015 s016 exploded view - 43 -.

  • Page 44

    F003 f002 f001 f005 f006 t001 t002 s028 r001 r004 r005 r003 r002 c013 c014 c015 c016 f007 f004 f008 f009 tr01 s023 s024 s017 s013 s019 s020 s022 s017 s007 s021 s013 s013 s017 r006 s007 s007 s026 s025 s017 s023 s027 s006 s029 r007 s005 s016 c001 c017 c005 exploded view - 44 -.

  • Page 45

    Ref.No part no. Description qty. Ref.No part no. Description qty. A001 70-046001-0 main heatsink 7 f007 11-01101-20 switch 1 a002 01-52510-10 amp module pcb boards(ah) 7 f008 01-52503-00 protect&softclipping led board 1 01-52510-20 amp module pcb boards(c) 7 f009 75-062001-0 sleeve 2 a003 67-046011-...

  • Page 46

    6 5 7 9 10 8 4 3 2 11 1 ref.No part no. Description qty. 1 88-046002-0 shipping carton box 1 2 88-046001-0 gift carton box 1 3 89-046001-1 m25 botton polyfoam 1 4 00-52500-20 m25 unit 1 5 87-046002-0 non-woven cloth bag 1 6 90-010003-0 polyfbag 1 89-046002-0 m25 top polyfoam 1 8 88-043003-0 m15acces...