Pioneer SX-750 User's Manual
Contents
1. Ceramic 0 01 CKDYF 103Z 50 Electrolytic 0 47 Bk CEA R47P 50 Ceramic 0 047 25V CKDBC 4732 25 Ceramic 0 047 25V CKDBC 4732 25 Ceramic CKDBC 473Z 25 Ceramic 0 047 25V CKDBC 473Z 25 0 047 25V CKDBC 4732 25 Ceramic 0 47p 500V CGB R47K 500 Ceramic 0 047 25V CKDBC 473Z 25 Ceramic CKDBC 473Z 25 Ceramic 0 047 25V CKDBC 473Z 25 Ceramic 390p 50V CKDYB 391K 50 Ceramic 390p 50V CKDYB 391K 50 150 50V CCDSL 151K 50 Ceramic CKDYF 1032 50 Electrolytic 100 16V CEA 101P 16 Electrolytic 220 16V CEA 221P 16 Mylar 0 047 50V CQMA 473K 50 Polystyrene 510p 50V CQSH 511J 50 Electrolytic 4 7 16V CSZA 4R7M 16 Electrolytic 1 25V Electrolytic 3 3 10V Electrolytic 0 22 35V Polystyrene 510p 50V Polystyrene 510p 50V CSZA 010M 25 CSZA 3R3M 10 CSZA R22M 35 COSA 511J 50 COSA 511J 50 Mylar 0 0047 50V COMA 472J 50 Mylar 0 0047 50V COMA 472J 50 Ceramic 0 04 50V CKDYF 4032 50 Electrolytic 220 6v CEA 221P 6 Ceramic CCDXL 120K 50 Polystyrene 330p 50V CQSA 331J 50 Ceramic 0 01 50V CKDYF 103Z 50 Ceramic 0 04 50V CKDYF 403Z 50 Ceramic 0 04 50V CKDYF 403Z 50 Electrolytic 4 7 35V CEA 4R7P 35 Electrolytic 47 6V CEA 470P 6 Electrolytic 220 16V CEA 221P 16 Ceramic 220p 50V CCDSL 221K 50 Ceramic 0 01 50V CKDYF 10322. Electrolytic CEA 101P 6 Ceramic CCDSL 0500 50 Ceramic CCDSL 050D 50 Electrolytic CEA 221P 35 Electrolytic CEA 221P 35 Electrolytic CEANL 4R7P 25 Electrolytic CEANL 4R7P 25 Mylar CQMA 122J 50 Mylar 122J 50 Mylar CQMA 562J 50 Mylar 562J 50 Mylar CQMA 183J 50 Mylar CQMA 183J 50 Mylar 823 50 Mylar 823J 50 Mylar COMA 272J 50 Mylar COMA 272J 50 OTHERS Nut B71 004 Washer ABE 001 53 5 I gt e 9 lt a lt tc o 12 6 110 WI 96 186052 o MS SO 9 2 oy 2X 125852 8947 01524 MU 01 MS MS 80 011061 400159 40814 4081 42 9081 8 001 Were My 58605250 9 022 3 s 9 y ZX BELVSZ 9 y MD 0959 080096 y i 24 Q AWG 046 AWG 046 AWE 073 AWM 094 AWR 099 No 4 AWG 046 No 8 21V AWE 073 No 33 21V AWR 100 No 7 41V 5 T 2 C2 20 Q3 AWR 099 No 11 41 04 AWR 099 No 9 aes 3 sSx 750 1 7 19 10 34 19V 0 1 19 AWR 099 23 099 No 17 AWR 099 No 1 30 AWG 046 No 1 8 AWR 099 No 8 2 41 _ 4 Parts List of Power Amplifier Assembly A
3. tee us 4 H E Es et eH 8 20 gp en NS ESL St ee ee LET b OIN i j E f x 48 M a L i HA1138 AM IC _ 73 ER E S HEEL 2 E la Eu E oed HA1196 E us 2 kbir 7061 nal Appearance of Transistors and ICs SA823 3C945A B 2SB507 e 250313 C 1234567 A7061AP 298527 Qa A7136P1 250357 1 Bi E 25 1166 B2 5 58541 50388 D 25 30 sx 750 TA7136P1 HA1137 HA1138 HA1196 25 461 B 25 535 Ks 2SC 1344 5678 HA1201 2SA725 49 124 FILTER amp MUTING ASSEMBLY AWM 094 9 9 25 733 2 0 04 0 2SC94SAx3 0 Dz 152413 2 i H AWE 073 1 AWE 073 No 22 32 AWE 073 44 AWH 046 No 28 19V AWG 046 No 7 19V 5 List of Filters amp Muting Assembly AWM 094 EMICONDUCTORS Diode Diode 152473 152473 Transistor 2SA733 Q Transistor 25 733 Transistor 2SC945 R Transistor 2SC9
4. 750 gt 099 24 33 AWG 046 No 6 AWG 046 No 5 AWM 094 No 3 STEREO _ 8 AWR 099 24 1086 6 5004 3 100 14 M 00 ID PHONO SIGNAL METER Parts List of Tuner AF amp Control Assembly AWE 073 SEMICONDUCTORS FET Transistor Transistor Transistor Transistor Transistor Diode Diode Diode Diode Diode Diode Diode Diode Zener Diode Zener Diode SWITCHES Rotary switch FUNCTION Lever switch TAPE MONITOR Lever switch DUPLICATE Lever switch MODE Lever switch MODE Push switch FM MUTING TRANSFORMERS COILS FM antenna coil FM RF coil FM RF coil FM O S C coil FM IF transformer FM IF transformer FM IF transformer 3SK45 B 2SC535 B 25 717 1201 1137 TA7061 AP HA1196 HA1138 TA7136 P1 TA7136 P1 2SA725 G 25 1344 0 or 28 1345 0 28A733 Q 152076 152076 152076 152076 18188 1 15188 1 152076 152076 152076 152076 152076 WZ 192 WZ 210 ASD 049 ASK 102 ASK 092 ASK 090 ASK 090 ASG 097 ATC 021 ATC 015 ATC 016 ATC 022 ATE 026 ATE 027 ATE 013 Description Part No AM O S C coil FM ceramic filter FM Ceramic filter FM Ceramic filter AM Ceramic filter RF Choke coil RF
5. Ts 22771 800 HU Rig as HANS 16 IE mi 10 9 4 j 6 1 L 3 MS d ieri n ma 4 a 88 Rs 150 04 39K FILTER 4 MUTING Ass y AWM 90 Ry 24K 225 PRT 90 Fy 25 su l E Q 1 gt 1 4 28313952 FD 0 0 EF Lime n 2 557 WK 065 Be QM 3 M EM om 55a 1 7 Sie Se 19V 4 SWITCHES AMP Assy 065 5 FUNCTION 5 LOUDNESS Sip SPEAKER e AM 0 WER FF 2 725 04 2SA726 73 2 2 SP 9 PHONO 5 3 SP OFF 4 AUX MIO OFF ON 4 SPB SP A B 5 TAPE MONITOR 52 HIGH FILTER 6 Toe Sn Bow DUPLICATE Sp MUTING u 1 OFF ON ON OFF Sa MODE 5 RELAY L 0 2501313 4 STEREO MONO 41 5 3250109 m RESISTORS 12 IN OHM 1 4W 55 TORELANCE UNLESS OTHERWISE NOTED MQ ja TATIS6P1 CAPACITORS 5 INuF UNLESS OTHERWISE NOTED pF NOTES lt gt mA SIGNAL VOLTAGE NECESSARY FOR OBTAINING 56W 8Q OUTPUT POWER 1k Hz DC VOLTAGE AT NO INPUT SIGNAL OC CURRENT AT NO INPUT SIGNAL 53 SP Cy 25 Rw43K TONE CONTROL
6. d He 9911250 999919 b 660 ASSW Nollo3lONd 414408 HIMOd ONI 038315 0000000 OOL YMY ASSY 414406 HIMOd G emas 990 duv 4 5379345 ae 3 HBT MY 974 05 8 u3wv3dS YOLVDIONI NOILISOd 1 xw ET 914 Sid e 23 TWIQ wamogd 246 T 7405 2 ee aa 0 d 2111 B r su til TEL H 4 4 2 13 me
7. Amplifier assembly AWK 065 Terminal SPEAKERS AKE 029 11 8 PACKING Vinyl bag 11 024 Operating instructions ARB 174 M T type antenna ADH 002 Sheet cover AHG 034 ide pad AHA 112 Packing case AHD 357 KU model AHD 358 KC model 12 SCHEMATIC DIAGRAMS P C BOARD PATTERNS AN 12 1 SCHEMATIC DIAGRAMS TUNER v AF Ass y AWE 073 10 2 MES ATI Va Tes Te TOM aay 71 a 3 RS Bg abe 81218 Dy Dg ISIBBFM x SWITCHES S FUNCTION MODE RELAY lent STEREO MONO So SPEAKER 2 FM LOUDNESS POWER OFF OFF ON 4 AUX MIC MONITOR a 1 0 2 HIGH FILTER S DUPLICATE Acid OFF OFF ON FM MUTING ON OFF RESISTORS Rowe IN OHM 1 4W 5590 TORELANCE UNLESS OTHERWISE NOTED M MQ poo CAPACITORS INwF UNLESS OTHERWISE NOTED pF NOTES SIGNAL VOLTAGE NECESSARY FOR OBTAINING 56W 8O OUTPUT POWER ik Hz V DC VOLTAGE AT NO INPUT SIGNAL lt mA 0 CURRENT AT NO INPUT SIGNAL CO 220 35 D PARTS LIST POWER SUPPLY Assy AWR 100 0 0 181886 0 0 SR3AN 8x4 0 STEREO IND BV SO mA fo 004 DE EMPHASIS AsS y 2 2 2801648 x2 I 095 9 e m 9561643 Ay 21K 181555 4 ate 5 D x d 209 P 50 Gp Opry GG POWER 0
8. 1 7 1 1 This Service Manual is applicable only to the KC KU model sz TRUE T 11 p me w CONTENTS T AT FRONT PANEL FACILITIES 3 CONNECTION DIAGRAM iniri A i PE CIRCUIT DISCRIPTIONS ET Oe OEM TU Mutina Circuit iarann ne xm m med el aug BA Gqudicer Amplifier dc cia stadi 2 20 26 tub SMicrophone Circuit 2 2 2 22 Geer Helden BS Control 22 gt 2 254 0 5 58 Power Amplifier ees cec a e E i etuer sa ats ues T INC OU EM M EN ADJUSTMENTS PN ______ ia Ia ada a Pa areg Power Amplifier Section ARI n EIER RO EXER OR RON ARRAY 1 E ES PARTS LOCATION EET Front Panal nik oo kb erica yee RE 10 2 Front Panel View with removed front panel
9. OSS e bia EE EU er exeo VIGW RE E D scs aerate Solas owen sae a VIRA a CENE e na 8 CORR OR A CR a 0 rrr DUELO So ee LIST ee er ee E c 7 a i COO D 1 GET SX 750 12 118 4 SCHEMATIC DIAGRAMS P C BOARD PATTERNS AND PARTS LIST 12 1 Schematic Diagrams 122 Miscellaneous Parts se 12 3 Internal Circuitry of Integrated Circuits 124 Filter amp Muting Assembly 094 12 5 Tone Control Assembly 046 12 6 Power Amplifier Assembly AWH 046 12 7 Power Supply amp Protection Assembly AWR 099 12 8 Power Supply Assembly AWR 100 12 9 Headphone Jack Assembly AWX 106 12 10 Tuner AF amp Control Assembly AWE 073 12 11 Amplifier Assembly 065 12 12 De emphasis Switch assembly AWX 095 1 SPECIFICATIONS Semiconductors ee ae 1 A 7 mue Ss 42 SE a a
10. 5 4 PHONO EQUALIZER AMPLIFIER IC TA7136P1 is used with independent left and right channels Grade G styrole capacitors and grade F metal film resistors comprise the equal izer elements leading to an RIAA deviation within 0 2dB from 30Hz to 15kHz Fig 6 sx 750 5 5 MICROPHONE CIRCUIT A 2 stage transistor amplifier monophonic is provided in addition to the phono equalizer ampli fier A selector switch cuts the AUX jack input when a plug is inserted into the MIC jack The amplified microphone signal is then supplied to both the left and right channels The FUNCTION switch is set to the AUX position when using a microphone Function SW B AUX Rech Mic Lch AUX Function SW Fig 7 5 6 TONE CONTROL CR type tone controls are connected to an ex tremely low output impedance flat amplifier IC TA7136 31dB gain Bass can be varied in the range of 8dB 100Hz and treble in the range of 9dB 7dB 10kHz A switch also allows the tone controls to be switch ON OFF R1 and R2 are designed to provide the same loss when the TONE switch is OFF as obtained with the TONE switch ON and the BASS and TREBLE controls at center positions flat Frequency response thus becomes flat when the TONE switch is set to OFF R3 and C1 form a 6kHz 6dB octave HIGH CUT filter which is connected following the TONE switch TONE CONTROL Fig 8 15 5 7 PROTECTION CIRCUI
11. 50 Ceramic CKDYF 1032 50 Electrolytic CSZA OR1M 35 Ceramic 0 01 50V CKDYF 1032 50 Ceramic 0 01 50V CKDYF 103Z 50 Ceramic 0 04 50V CKDYF 4032 50 Ceramic CKDYF 40327 50 Ceramic 0 01 50V CKDYF 1032 50 Ceramic 150p 50V CCDSL 151K 50 Ceramic 47p 50V CCDSL 470K 50 Ceramic 0 04 50V CKDYF 403Z 50 Ceramic CKDBC 4732 25 0 047 25V Electrolytic 10 16V CKDBC 4732 25 CEA 100P 16 CEA 100P 16 CSZA 010M 25 CSZA 010 25 Electrolvtic Electrolvtic Electrolvtic CEA 221P 25 CEA 221P 25 CEANL 4R7M16NF 101P 6 CEA 101P 6 Electrolytic Electrolytic Electrolytic Electrolytic Electrolytic CCDSL 0500 50 CCDSL 0500 50 CCDSL 270K 50 CCDSL 270K 50 CQSA 102G 50 Ceramic Ceramic Ceramic Ceramic Polystyrene 102G 50 COSA 352G 50 COSA 352G 50 CSZA 2R2M 25 CSZA 2R2M 25 Polystyrene Polystyrene Polystyrene Electrolytic Electrolytic CCDSL 221K 50 CCDSL 221K 50 CSZA 2R2M 25 CCDSL 101K 50 CCDSL 150K 50 Ceramic Ceramic Electrolytic Ceramic Ceramic CSZA 2R2M 25 CEA 221P 35 CCDSL 221K 50 CCDSL 221K 50 124K 50 Electrolytic Electrolytic Ceramic Ceramic Mylar COMA 124K 50 CEA 100P 16 CKDYF 4032 50 4032 50 CCDSL 820K 50 Mylar Electrolytic 10 Ceramic 0 04 Ceramic 0 04 Ceramic 82p CCDSL 820K 50 CKDYF 4032 50 Ceramic 82p Ceramic 0 04 ACK 015 ACM 006 Tunning capac
12. DIAL ILW INATE 300mA 3 W om iD a POWER ASS Y AWH 046 MISCELLANEOUS PARTS INDUCTORS Peon Transistor 280 388 R Transistor 2SB 541 R Transistor 2SD 388 R Transistor 2SB 541 R Lamp assembly 8V 0 3A AEL 060 Lamp assembly 8V 0 3A AEL 060 Lamp assembly 8V 0 3A AEL 060 Lamp with leads 8V 50mA AEL 064 Lamp with leads 8V 50mA AEL 068 Lamp with leads 8V 50mA Lamp with leads BV 50mA Lamp with leads 8V 50mA Lamp with leads BV 50mA AEL 066 AEL 067 AEL 069 AEL 069 Fuse 1 5A AEK 104 Fuse 0 5A AEK 107 Fuse 0 8A AEK 111 Fuse 0 8A AEK 111 Fuse 4A AEK 100 5 TRANSFOMER Description ATT 264 ATT 301 T22 025 AXB 004 T24 030 Power transformer KU model Power transformer K C model Ferrite balun Ferrite bar antenna Chock coil ESISTOR m Carbon film 2 2M YW RDWPS 225 SxX 750 CAPACITORS Electrolytic 15 000 50V ACH 057 Electrolytic 15 000 50V ACH 057 Ceramic 0 01 150V DC1 4kV ACG 003 Ceramic 0 01 150V DC1 4kV ACG 001 12 3 INTERNAL CIRCUITRY INTEGRATED CIRCUITS HA1137 FM IF IC
13. Parts List of Power Supply Assembly AWR 100 SEMICONDUCTORS L km eee 151885 151886 151886 151886 151886 SR3AM 8 SR3AM 8 SR3AM 8 SR3AM 8 t RESISTORS Metal oxide 4 7k 2W Metal oxide 4 7k 2W CAPACITORS Description No RS2P 472K RS2P 472K Electrolytic 470 10V CEA 471P 10 Electrolytic 0 01 250V ACG 001 Electrolytic 0 01 250V ACG 001 Electrolytic 0 01 250V ACG 001 Electrolytic 0 01 250V ACG 001 ACG 001 ACG 001 Electrolytic Electrolytic THERS Fuse clip AKR 013 Fuse clip AKR 030 SX 750 12 9 HEADPHONE JACK ASSEMBLY AWX 106 AWR 099 No 3 AWR 100 15 AWR 099 No 5 AWR 099 No 2 AWR 099 15 4 PLO POWER IND S10 b F 9 1 2 SPEAKER A OUT gt 10 6 8 2 SPEAKER A OUT Lch T Parts List of Headphones Jack Assembly AWX 106 RESISTORS Symbol Metal oxide 150 2W RS 2P 151J Metal oxide 150 2W RS 2P 151J Carbon film 27 RD PS 270 64 FM 13 319 FM 8 13V 11 9 250717 S o SIGNAL METER 0 12 B 13 9 IF KILLER QUT 22 AM INPUT 219 C 22 n5 Ry 560 0001 Cgc 00035 m 2 2 PHONO 2 473 TSK Ras 910K 3 T 100K B 21V 330 5 i 25mA Ren PHONO a e Ra 560 Cas0001 00035 For units which amplifier assembly AWK 065
14. a e aa ad a 40 Amplifier Section Continuous Power Output from 20 Hertz to 20 000 Hertz Both channels driven 50 watts per channel 8 ohms 60 watts per channel 4 ohms Total Harmonic Distortion 20 Hertz to 20 000 Hertz from AUX Continuous Rated Power Output No more than 0 1 25 watts per channel power output 8 ohms 1 watt per channel power output 5 No more than 0 05 more than 0 05 Intermodulation Distortion 50 Hertz 7 000 Hertz 4 1 from AUX Continuous Rated Power Output No more than 0 1 25 watts per channel power output Sohms No more than 0 05 1 watt per channel power Outputs ohms No more than 0 05 Damping Factor 20 000 2 30 Input Sensitivity Impedance CDS c 2 5mV 50k ohms Rau um mes AT s E er 5mV 50k ohms CUT A 150mV 50k ohms MAREPEAWVT e 150mV 50k ohms So iol rev 150mV 50k ohms TAPE PLAY 2 DIN connector 150mV 50k ohms PHONO Overload Level T H D 0 1 200mV 1kHz Output Level Impedance 150 oco se rape qe s METRE 150mV TAPE 2 DIN connector 30mV 80k ohms BEBO ERES a i A B A B 5 6 Low Impedance Frequency Response PHONO RIAA equalization LARA C 30 Hertz to 15 000 Hertz 0 2dB Fi 10 Hertz to 50 000 H
15. is used in place of IC Q9 Q10 TA7136P indicated by red line see Page 73 1 IF KILLER CENTER METER 32 28 27 0 152076 5 2 5 ES R22 330 5 3 Cu 04 Ps it ez 4 5 6 4 0 1131 b 5 H U R 33 9 D D4 1 182076x3 43 20 VR 47K z 25 Si 41 18 23 OUT D4 152076 H trm r VCO KILLER x 355 1 222 35 Ro H 24 ST IND ba low 8 MUTING Assy AWM 094 i e Lo O O sb 1 PE 33K R 47K 740 st Ts 733 100 30 FM SIGNAL METER OUT 3 FM SIGNAL METER IN 42 1 zx 93 d BE 5 2 O16 R TO TONE CONTROL Ass y x 5 a L I 5631646 6 4 REC REC MON REC L CHANNEL R CHANNEL l 2 AWG 046 8 046 21 094 No 1 19V AWG 046 No 7 19V AWH 046 No 28 19 34 33 30 31 29 AWX 095 3 59 AWX 095 1 40 AWX 095 2 41 AWX 095 No 4 42 43 AWM 094 No 2 44 Np Ease DE eg omm Pam E
16. 00uF electro lytic capacitor 6 ADJUSTMENTS 6 1 AM SECTION 1 2 3 Set function switch to Connect AM signal generator through 1k ohm resistor to AM antenna terminal Set DUPLICATE switch to OFF and connect an AC voltmeter to TAPE 1 REC jacks Set AM SG for 400Hz 30 modulation 74dB output Set SX 750 dial indication and AM SG fre quency for 600kHz Adjust T8 core for maximum reading on AC voltmeter Set SX 750 dial indication and AM SG fre quency for 1 400kHz 11 12 13 14 Adjust TC2 for maximum reading voltmeter Set AM SG for 30dB output Set SX 750 dial indication and AM SG fre quency for 600kHz Adjust T8 and bar antenna core for maximum reading on AC voltmeter Set SX 750 dial indication and AM SG fre quency for 1 400kHz Adjust TC2 TC4 for maximum reading on AC voltmeter Repeat steps 10 13 to eliminate variations AC voltmeter readings AC voltmeter AM signal generator Fig 14 SECTION measuring equipment as shown in 1 SG to 100 modulation 75kHz iation at 400Hz and 100dB output SX 750 front panel set FM switch to ON muting to OFF and VOLUME control to inimum position st TC6 to center of turning range ine FM SG and SX 750 to dial readings of djust 74 core for maximum indication signal meter just T6 core for center of scale indication on uning meter t FM S
17. 1 Dial 1 illumination 1 1 S MPX d od ox 4 Ratio detector T DTE Muting HA1136 Auto SW DD gt indicator AM 13V i 25 ON L5 1 FM MUTING a TUNING meter ATA POWER AMP PROTECTION CIRCUIT a Q 1 5V 35V IN 55 poen Ww 3 FILTER Sw 24 4 5 H JL i 136 Em Relay drive detection ER SUPPLY Program Sob 520 54 526 SSS 41V indicator 1 3 FM Regulator PHONO 1 0 1 O5 dus me Lodi LR PHONES SPEAKERS S FUNCTION switch 5 SPEAKERS switch 1 AM 1 PONER OFF E 3 PHONO 3 OFF 4 AUX MIC 4 B Power 5 A B indicator ie 5 CIRCUIT DESCRIPTIONS 5 1 AM TUNER Composed of single IC HA1138 combining a 1 stage RF amplifier and a 2 stage IF amplifier Fig X 5 2 FM TUNER Front End The outstanding performance exemplified by the remarkable 8048 imaging and 90dB spurious rejection originates in the dual gate MOS FET RF amplifier and 4 gang variable capacitor tuning circuit A modified Clapp circuit is employed in the local oscillator leading to high frequency Stability Since the output is taken from the oscillator tuning circuit higher harmonics in the oscillator signal and spurious response become reduced Antenna SX 750 IF Am
18. 100 No 15 AWH 046 22 AWX 106 No 1 AWH 046 36 13 5V 250945 22 AWE 073 No 26 13V AWE 073 No 9 13V PL8 AWE 073 24 AWX 106 No 4 PL9 1 S10 b F 2 SPEAKER OUT A R ch 15 7 6 PL1 PL2 PL3 2 AWX 106 No 3 ri PEAKERAL GRADI E C HEREIN Parts List of Power Supply amp Protection Assembly AWR 099 Q1 H 1 25 1649 Carbon film 203 or 2SC869 C Transistor 2SC1649 N or 2SC869 C Transistor 25 1647 25 945 Carbon film RD PS 153 Carbon film RD PS 153 Carbon film RD PS 154 Carbon film RD PS 153 Carbon film RD PS 153 Transistor 25 1647 25 945 Transistor 25 823 or 2SA733 Q Transistor 2SC1647 P or 2SC945 A Carbon film RD PS 153 Carbon film RD PS 154 Carbon film RD PS 822 Carbon film RD PS 332 Carbon film RD PS 683 Carbon film RD PS 470 Metal oxide RS1P 221K Transistor 2SC1167 Y or 2SC1384 R Transistor 2SD313 D Transistor 25 945 Wire wound RT5B 151K Carbon film RD PS 273 Transistor 250313 0 Carbon film RD PS 223 Carbon film RD PS 392 Carbon film 330 Carbon film 332 Carbon film 102 Transistor 25 945 0 Transistor 2SB507 D Diode 151554 Diode 151554 Diode 151554 Diode 151554 Diode 181555 CAPACITORS Diode 151555 Diode 181554 Electrolytic 0 22 10V Diode 151555 Electrolytic 0 2
19. 2 10V Zener diode WZ 140 Electrolytic 330 Electrolytic 330 6V Electrolytic 3 3 10V Carbon film 102 Carbon film RD PS 102 CEA 331P 6 CEA 331P 6 CEA 3R3P 10 Zener diode WZ 240 Zener diode WZ 140 Electrolytic CEA 221P 16 Electrolytic 220 16V CEA 221P 16 RESISTORS Electrolytic 100 35V CEA 101P 35 Electrolytic 100 50V CEA 101P 50 Carbon film RD PS 272 Carbon film 272 Carbon film 272J Carbon film RD PS 272J Carbon film 473 Electrolytic 100 50V CEA 101P 50 CEA 4R7P 35 CEA 221P 16 CEA 101P 35 CCDSL 101K 50 CEA 101P 50 Electrolytic Electrolytic 220 16V Electrolytic 110 35V Ceramic 100p 50V Electrolytic 100 50V Carbon film RD PS 473 Carbon film RD PS 153 Carbon film 153 CEA 101P 50 CEA 331P 50 Electrolytic Electrolytic 330 50V i CEA 331P 50 Carbon film RD PS 153 Carbon film RD PS 153 OTHERS Carbon film RD PS 222 Carbon film RD PS 820 Heat sink ANH 117 0 Heat sink ANH 259 0 Relay ASR 018 61 12 8 SUPPLY ASSEMBLY AWR 100 4 12 48V 02 05 1 1886 4 C2 Cs 13 48 De 03 SR3AM 8x4 01 Co 1 41 3 E 6 4v 4 TI No 4 6V 9 7 6 4 3 5 8 1 m L mom AWH 046 10 No 41V AWH 046 No 5 No 20 41V C FAC120V GE
20. 45 R Transistor 2SC945 R Carbon film Carbon film 910 Carbon film 2 4 Carbon film 2 4k Carbon film RD PS 911 RD PS 911 RD PS 242 RD PS 242 RD PS 102 Carbon film RD PS 513 Carbon film 150k RD PS 154 Carbon film 10k RD PS 103 Carbon film 75k RD PS 753 Carbon film RD PS 243 Carbon film 180 RD PS 181J Carbon film 4 3k RD PS 432J Carbon film 150k RD PS 154J Carbon film 150k RD PS 154 Carbon film RD PS 102 Carbon film RD PS 154 Electrolytic 2 2 25V Electrolytic 2 2 25V Electrolytic CSZA 2R2M 25 CSZA 2R2M 25 CEA 100P 35 Electrolytic CEA 101P 35 CKDYF 403Z 50 CSZA 010M 25 Ceramic Electrolytic Low pass filter ATF 033 L type terminal 035 SX 750 51 12 55 TONE CONTROL ASSEMBLY AWG 046 2 1 7136 1 C R Lch In 54 N 047 25 22K VR2 a 100K Cis 0 082 0 018 43K 4 3 96 2 In 60 047 25 2 2K gt 17 T Ce x SP m 8 0 136 1 046 30 AWH 046 29 AWE 073 15 AWE 073 16 1 2 3 4 5776 AWE 073 No 34 19V AWM 094 No 1 19V AWH 046 28 19V AWE 073 33 21 lt 1 AWH 046 No 21 21V 2 Parts List of Tone Control Asse
21. 561 Carbon film 56k RD PS 563 Carbon film RD PM 153 Carbon film 56 RD PS 560 Carbon film RD PS 471J Carbon film RD PS 102 Carbon film RD PS 222 Carbon film RD PS 163 Carbon film 1k RD PS 102J Carbon film 100k RD PS 104 Carbon film RD PS 222 Carbon film 5 6k RD PS 562 Carbon film 222 Carbon film RDVPS 222 Carbon film 2 RD PS 222 Carbon film RD PS 222 Carbon film 5 RD PS 222 Carbon film RD PS 303 R43 Carbon film 30k RD PS 303 R44 Carbon film 47k RD PS 4736 Carbon film RDVPS 683 R45 Carbon film 47k RD PS 4736 Carbon film RD PS 683 Carbon film RD PS 822 Carbon film RD PS 622 Carbon film 2 RDVPS 622 Carbon film RD PS 394 Carbon film RD PS 822 R48 Carbon film 3 3k RD PS 332 R49 Carbon film 3 3k RD PS 332 Carbon film RD PS 101 Carbon film RD PS 394 Carbon film RD PS 104 Carbon film 104 Carbon film 105 Carbon film RD PS 151 Carbon film 150 RDVPS 151J R54 Carbon film 39k RD PS 393 R55 Carbon film 5 1k RD PS 512 Carbon film 3 3k 332 Carbon film RD PS 104 Carbon film RD 4PM 104 Carbon film RD PS 272 Carbon film RD PS 104J Carbon film 2 2k RD PS 222 R58 Carbon film 1 RD PS 102J R59 Carbon film 680 RD PS 681 R6O Carbon film 47 RD PS 470 CAPACITORS Carbon film 100 RD PS 101 Ceramic CCDSH 150K 50 Ceramic CCD
22. 99 Knob TONE AAD 013 Knob HIGH FILTER AAD 013 Knob BALANCE AAB 099 nob TUNING AAA 036 TAPE CE VOLUME LOUONESS MODE OUPLICATE 3 E M Y 2 SOURCE 2 nob FM MUTING AAD 112 hone jack MIC AKN 013 nob FUNCTION AAB 100 nob TAPE MONITOR AAD 013 nob DUPLICATE AAD 013 nob MODE AAD 013 nob LOUDNESS AAD 013 nob VOLUME AAB 100 10 2 FRONT PANEL VIEW with removed Front panel Double meter AAW 040 Dial pointer assembly AAF 048 INDICATOR AEC 241 POWER STEREO Phone jack Headphones AKN 010 Rotary switch SPEAKERS ASA 038 Lever switch TONE ASK 090 Lever switch HIGH FILTER ASK 090 Variable resistor BASS ACV 138 Variable resistor TREBLE ACV 138 Variable resistor BALANCE ACV 135 INDICATOR FM PHONO AUX AEC 255 Tuning shaft assembly AXA 124 nob FM MUTING AAD 112 Phone jack MIC AKN 013 otary switch FUNCTION ASD 049 ever switch TAPE MONITOR ASK 102 Lever switch DUPLICATE ASK 092 Lever switch MODE ASK 090 Lever switch LOUDNESS ASK 090 Variable resistor VOLUME ACV 179 28 10 3 Power amplifier assembly AWH 046 Power supply amp Protection assembly AWR 099 Power transfomer ATT 264 KU model ATT 301 KC model Electrolytic capacitor ACH 057 Pully A
23. Angle Filter amp muting assembly 094 4 crew 3x6 _ ABA 048 Wire saddle E UY 3x6 Screw 3x6 ABA 048 Tuning drum assembly AXA 070 Rotary switch FUNCTION ASD 049 Push switch FM MUTING ASG 097 Lever switch DUPLICATE ASK 092 Lever switch TAPE MONITOR ASK 102 116 PART VI NOTE Parts indicated in green type cannot be supplied Shaft M49 025 ully AEC 101 Headphone jack assembly AWX 106 Special nut ABN 018 ABA 002 Dial pointer assembly AAF 048 Nylon sheet AEC 191 Screw ABA 002 switch ASA 038 Screw ABA 002 Screw 3x6 ABA 048 p termimar 2P y Side frame Screw 3x6 Angle Screw 3x6 ABA 048 Tone control assembly AWG 046 Special nut ABN 018 S b chassis ABA 048 1 2 3 117 PART VII Although there are some units in the 8 750 NOTE series which do not contain green line encircled Parts indicated in green type cannot be supplied components this is not an error AC power cord Ferrite bar antenna Screw 3x10 ABA 082 Screw ABA 002 Strain relief 079 B Screw Screw for ground 017 Screw 3x8 ABA 057 Washer M3x0 5t ABE 011 De emphasis assembly AWX 095 Rear panel erminal antenna AKA 002 AC socket OUTLETS AKP 004
24. Choke coil RF Choke coil RF Choke coil Choke coil RF Choke coil RF Choke coil RESISTORS Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film 2 2uH 2 2uH 2 2uH 2 2uH 18uH 2 2uH 2 2uH 5 6k 1 8k 22 27 4 7k 10k 4 7k 22 22k 100 56 56 560k 47k 2 2k 8 2k 15k 470 470 ATB 013 ATF 013 ATF 013 ATF 013 ATF 027 T24 028 T24 028 T24 028 T24 028 ATH 007 T24 028 T24 028 Description Part No 562 RDAVS 182 220 RD VS 270 RDAVS 151 102 472 RD VS 103 RD VS 472 RD AVS 222 RD PS 101 RD VS 220 RDAVS 223 RD PS 101 RDVPS 331 331 560 RD PM 560 RD PS 564 471 RD PM 331 RD PS 473 RD PS 222 RD PS 822 5 682 RD 4PS 332 RD PS 153 471 471 RD PM 562 562 RD PS 221 Carbon film 3 3k RD PS 332 Carbon film RDVPS
25. EC 153 29 Lamp assembly AEL 060 Acrylic board AEC 251 Tuner AF amp control assembly AWE 073 Tuning drum assembly AXA 070 Filter amp muting assembly AWM 094 Tuning shaft assembly AXA 124 amp assembly AEL 060 Lamp assembly AEL 060 104 BOTTOM Tone contr AWG 046 NE m m ud Rotary switch SPEAKER ASA 038 Cover Capaciter Power transfomer ATT 264 Power supply assembly AWR 100 Power amplifier assembly AWH 046 8 TRIP sx 750 assembly s TA AT KS 144 4 gt gt 46 a 4 lt 4 e aoe PN Tuner control assembly Mur SER AWE 073 4 446464 4 ae we ee 2 MAD 10 5 REAR VIEW Ferrite bar antenna Slic AXB 004 ASI Terminal ANTENNA AKA 002 CAUTION 00 NOT REMOVE SCREWS SEE BOTTOM NOTICE Terminal INPUT AKB 027 Terminal TAPE 1 AKB 027 Terminal TAPE 2 AKB 027 REC PB connector AKP 007 witch DE EMPHASIS 15 Wooden cabinet 053 mm pm CAUTION SPEAKER IMPEDANCE 40 OR MORE SPEAKER 82 OR MORE SPEAKER Laie es L OUTLETS SWITCHED UNSWITCHEC power cord ADG 005 Terminal SPEAKER AKE 029 ske
26. Ferrite antenna 300u V m Ext antenna fir osc 727227 15 A AAA a 35dB aoe awa ssp SENTIT 50dB A 40dB TE 65dB Ante na Built in Ferrite Loopstick Antenna Miscellaneous Power 120V 60Hz Power Consumption 160W UL 350W max 480 W 149 H 371 D mm 18 7 8 W x 5 7 8 H x 14 5 8 D in Weight without package 13 7kg 30 Ib 2 oz withipackage 15 3kg 33 Ib 11 oz Furnished Parts 22 7 1 1 NOTE Specifications and design subject to possible modification without notice due to improvements SX 750 2 FRONT PANEL FACILITIES POWER INDICATOR LAMP Lights when SPEAKERS switch is moved to any position from POWER OFF and power is supplied to the receiver SPEAKERS SWITCH Functions both as power switch and speaker selection switch POWER OFF AC power is off A Sound will be heard from speakers con nected to A speaker terminals OFF No sound will be heard from speaker sys tems This position should be used when listening with headphones 1 Sound will be heard from speakers con nected to B speaker terminals A B Sound will be heard from speakers con nected t
27. G output to 8 10dB and adjust cores of 1 T2 and for maximum indication on meter ne FM SG and SX 750 to dial readings of FM SG output to 100dB and adjust TC6 for maximum indication on Signal meter 12 13 14 15 16 17 19 20 Set FM SG output to 8 10dB and adjust 5 and TC6 for maximum indication on Signal meter Repeat above adjustment steps 57411 and adjust for optimum conditions Tune FM SG and SX 750 to dial readings of 90MHz Adjust T5 core for maximum indication on Signal meter Detune SX 750 to noise only Adjust T6 for center of scale indication on Tuning meter Tune FM SG and SX 750 to dial readings of 98MHz Set FM SG output to 60dB and adjust upper core of T7 for maximum reading on AC volt meter Adjust lower core of T7 for minimum audio frequency output distortion Set FM SG for 100dB output and adjust VR1 so that Signal meter indicates 5 of the scale Distortion meter AC voltmeter FM signal generator Fig 15 19 6 3 Adjustment 1 2 3 Connect the output signal 19kHz of MPX SG Connect measuring equipment as shown in Fig 16 Tune FM SG and SX 750 to dial readings of 98MHz Set FM SG for 60dB unmodulated output PILOT OUT terminal to the horizontal input of an oscilloscope and pin 20 of the tuner assembly AWE 073 via a probe to the oscilloscope vertical input Adjust VR2 s
28. P 10 47p 10p 100 12 12 DE EMPHASIS SWITCH ASSEMBLY AWX 095 C2 0 0012 Parts List of De emphasis Switch Assembly AWX 095 Description Part No Slide switch DE EMPHASIS ASH 015 Mylar capacitor 0 0012 50V CQMA 122J 50 Mylar capacitor 0 0012 50V 122J 50 74 m PIONEER ELECTRONIC CORPORATION 4 1 Meguro Meguro ku Tokyo 153 Japan U S PIONEER ELECTRONICS CORPORATION 75 Oxford Drive Moonachie New Jersey 07074 USA PIONEER ELECTRONIC EUROPE N V Luithagen Haven9 2030 Antwerp Belgium 4 PIONEER ELECTRONICS AUSTRALIA PTY LTD 178 184 Boundary Road Braeside Victoria 3195 Australia 76E04Y 5IK MAY 1976 2 Printed Japan lt 181 0 gt AMENDMENT TO SX 750 KU KC Service Manual A misprint appears on page 52 12 5 TONE CONTROL ASSEMB LY AWG 046 in point of voltage value Please replace the original P C Board by the ones provided below AWH 046 No 30 AWH 046 No 27 AWE 073 No 15 Ti No 16 1 8 AWE 073 34 19V AWM 094 No 1 19V AWH 046 No 28 19V AWE 073 No 33 21 AWH 046 21 21V a iM aw hm 5 ina i AM FM STEREO RECEIVER X 75 KC KU SIGNAL METER TUNING METER A TUNER u AF 55 AWE 073 A 2 0 38 45
29. SL 101K 50 Ceramic CKDYF 1032 50 Ceramic CCDSL 020C 50 Ceramic CKDYF 1032 50 Carbon film 1k RD PS 102 R63 Carbon film 100k RD PS 104 R64 Carbon film 100k RD PS 104 R65 Carbon film 2 2k RDVPS 222 Carbon film 2 2k RD PS 222 Carbon film 100k RDJAPS 100K Ceramic CKDYF 1032 50 R68 Carbon film 100K RD PS 100K Ceramic CCDSH 180K 50 R69 Carbon film 47k RD PS 473 Ceramic CCDSH 180K 50 R70 Carbon film 47k RD PS 473 Ceramic CCDSL 040D 50 Metal film 1 54k RN PT 1541F Ceramic CGB R39K 500 Metal film 1 54k RNAPT 1541F Ceramic CCDRH 150K 50 R73 Metal film 75k RN74PT 7502F Ceramic CCDCH 080F 50 R74 Metal film 75k RNAPT 7502F Ceramic CCDCH 330K 50 R75 Metal film 910k AW 9103F Ceramic CCDCH 150K 50 Metal film 910k RNAPT 9103F Ceramic i CKDYB 103K 50 Carbon film 560 RD PS 561 R78 Carbon film 560 RD PS 561 Ceramic CCDSL 101K 50 Ceramic 1032 50 R79 Carbon film 1 2k RD PS 122 Ceramic 2 1032 50 R80 Carbon film 1 2k RD PS 122 Ceramic 1 CKDYF 103250 R81 Carbon film 100k RD PS 104J Ceramic CCDSL 150K 50 Carbon film 100k RD PS 104J R83 Carbon film 330k RD PS 334J R84 Carbon film 11k RDMPS 113 Carbon film 18k RD PM 183 Carbon film 91k RD PS 913 Ceramic CKDBC 4732 25 Ceramic 1 4732 25 CKDBC 4732 25 CKDBC 4737 25 Ceramic 103250
30. SZA 010M 25 Electrolytic CSZA 010M 25 Ceramic CCDSL 560K 50 Ceramic CCDSL 560K 50 Ceramic CCDSL 121K 50 CCDSL 121K 50 CEA 221P 6 CEA 221P 6 CEA 101P 35 CEA 101P 35 Ceramic Electrolytic Electrolytic Electrolytic Electrolytic CCDSL 150K 50 CCDSL 150K 50 CEA 221 6 CEA 221P 6 CCDSL 181K 50 Ceramic Ceramic Electrolytic Electrolytic Ceramic CCDSL 181K 50 CCDSL 181K 50 CCDSL 181K 50 CKDYF 4032 50 CKDYF 403Z 50 Ceramic Ceramic Ceramic Ceramic 0 04 Ceramic 0 04 180p 0 047 0 047 CKDYF 4732 50 CKDYF 473Z 50 CKDYB 561K 50 CKDYB 561K 50 ACE 008 Ceramic Ceramic Ceramic 560p Ceramic 560p Metallized mylar 1 OTHERS Heat sink ANH 117 T63 009 AKM 018 AF chock coil 2 2uH Contact strip 3PL type o 9 gt ES LU 9 o a 2 o tc gt gt o tc o a 12 7 ASE NI LI v MISSY 08 001 9911252 Lo 21991254 sq gt t 1791252 55515150 6 9 wgiggse V6 AGL AVE 665151 Lg sg 6 9125 0 ox a 0 8 R29 150 SW 073 18 AWH 046 33 AWR 100 No 12 48V AWH 046 29 37V AWR 100 No 13 48V b on og AWH 046 No 16 AWH 046 No 6 AWH 046 No 11 AWH 046 No 1 2 106 2 AWR
31. T This protection circuit functions to protect the speakers and the power amplifiers from damage due to short circuit of the load etc and performs a muting operation to cut noise and distortion which occur when switching the power on and off The circuit is shown in Fig 15 and consists of a bridge type over current and overload detector a differential amplifier DC voltage detector and a power switch ON OFF detector section Relay Driving Circuit Q4 Q6 in Fig 9 circuit In the normal condition reverse bias is applied to the base of Q4 and Q4 is in a off state When one of the above mentioned detection circuits goes on current flows through R11 the base potential falls and Q4 is turned on Consequently Q5 comes on and Q6 goes off When Q6 goes off the current of the relay circuit is cut to release the switch of the output circuit When the power switch is turned on a delay operation occurs in this circuit R17 and C3 in the base circuit of Q6 are the time constant elements which determine the delay time When the power switch is turned on C3 charges to a potential of 60 volts through R17 and R18 and Q6 is kept in the off state during this time When the power source is switched off the muting operation of Q5 prevents shock noise In the normal condition the potentials of 33 volts and 5 1 volts are applied to Q5 through R14 and R15 The resultant poten tial at the base of Q5 is 1 volt in the cutout condition Wh
32. WH 046 SEMICONDUCTORS TA Transistor 2SA798 F Transistor 2SA798 F Transistor 2SC1438 V Transistor 25 1438 Transistor 2SD357 C Transistor Transistor Transistor 280357 25 527 25 527 Diode Diode Diode 152473 152473 STV4H STV4H RESISTORS RS1P 561K RS1P 561K 564 RD PS 564 RD PS 222 Metal oxide Metal oxide Carbon film Carbon film Carbon film RD PS 222 RD PS 563 RD PS 563 RD PS 563 RD PS 563 Carbon film Carbon film Carbon film Carbon film Carbon film RD PS 202 RD PS 202 RD PS 182 RD PS 182J RD PS 112 Carbon film Carbon film Carbon film Carbon film Carbon film RD PS 112 RD PS 273 RD PS 273 RD PS 392 RD PS 392 Carbon film Carbon film Carbon film Carbon film Carbon film RD PS 101 RD PS 101 RD PSF 151 RD PSF 151 151 Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film RD PSF 151 RD APSF 100 100 RD PSF 100 100 RT5B OR5K RT5B OR5K RT5B OR5K Wire wound Wire wound Wire wound 57 RT5B OR5K RD APSF 100 Wire wound Carbon film RD PSF 100 RD PS 100 RD PS 100J Carbon film Carbon film Carbon film Semi fixed Semi fixed ACP 019 ACP 019 CAPACITORS mil Electrolytic C
33. connected to the receiver may be recorded onto the other with or without editing For normal operation this switch must be in OFF upper position PROGRAM SOURCE INDICATORS Indicate program source selected by means of FUNCTION switch TUNING KNOB For selection of FM or AM stations FM MUTING BUTTON For selection of FM broadcasts button should be in ON released position When button is in ON position unpleasant interstation noise is suppressed When signal strength is poor it may not be possible to bring in the desired station if MUTING is ON In this case press button to place it in the OFF position FUNCTION SELECTOR For selection of program source AM AM broadcasts FM FM broadcasts PHONO Playing records AUX MIC For use of component connected at AUX terminals of receiver or microphones which may be plugged into MIC jack NOTE AUX and MIC program sources cannot be used simul taneously When using AUX hi fi component micro phone should be disconnected MIC JACK Accepts standard plug Microphone input signal enters both R and L channels TAPE MONITOR SWITCH For program sources other than tape deck playback REC or PLAY SOURCE For program sources other than tape deck playback 2 For monitoring of playback or record mode of tape deck connected to TAPE 2 terminals REC or PLAY NOTE When not monitoring record or playback mode of a tape deck switch should be
34. ctor becomes reduced and clipping occurs power supply voltage is limited by IC voltage endurance For this reason current from an external source is inserted at Q3 and Q6 collectors to become I and L The same current amounts are ob tained as I and I from the emitters Q3 and Q6 therefore operate with adequate current and distortion at this stage becomes remark ablly improved A feedback amplifier amplifies the demodulated output Composite signal AF amp Fig 4 Equivalent Circuit of Demodulator T Current Phase comparator Demodu 2 Trigger circuit lator A LI LI n fx1 2 192 oE O a o E 1 9 STEREO Raf Sepa Raf Muting Lout adj Rout signal indicator Fig 3 Block Diagram of HA1196 14 53 FM MUTING CIRCUIT At time of detuning more than 70kHz and with an antenna input of less than 10dB 1u V a DC voltage is produced at pin 12 of HA1137 This voltage is employed as the muting trigger With the MUTING switch ON Q1 becomes ON Q2 OFF in the 91 92 Schmitt circuit as the muting trigger is produced 98 becomes ON when Q2 is OFF and Q4 Q5 and Q6 also become ON With Q4 amp 5 ON the FM output becomes grounded while IC output is grounded by Q6 to apply muting OUTPUT HANS Fig FM Muting Circuit
35. cuit functions and the relay switch of the output circuit is turned off After the cause of the overload is removed the bias of Q1 is reduced and the relay switch turns on tc automatically restore normal operation Fig 18 b shows the equivalent circuit at the time of a negative half cycle In this circuit a potential is produced between b and e as above and 01 15 turned on Power amplifier Relay driving circuit Relay Fig 12 Equivalent Circuit of 5 750 5 8 POWER AMPLIFIER CIRCUIT Composed of differential first stage all stages direct coupled pure complementary OCL circuit Open gain at 1kHz is approximately 80dB and NFB amount is approximately 50dB R3 and R4 are provided with this circuit in order to obtain adequate stability even with the NFB disconnected Q1 form a differential amplifier 100 d c feed back is applied from the junction point of the power stage to the base of 01 so the potential of the junction point is always maintained at the same level 5 9 POWER SUPPLY Two windings are provided in the power trans former secondary and each is separately bridge rectified One of these is sent as 48 VDC to the voltage stabilizer circuit to become 13V 33V and 37V regulated voltages for supply to each assembly The other secondary voltage is bridge rectified and becomes 4IV or supply to the power amplifier predriver stage Extremely low power supply impedance is maintained by a 15 0
36. en the power supply is turned off comprise the relay driving Over current Power amplifier M he of 5 1 volts disappears immediately due to the small time constant of the power circuit Thus a positive base potential remains switching Q5 on which in turn switches off Q6 and hence the relay Detection of DC Voltage This is a differential amplifier consisting of Q2 and Q3 as shown in Fig 10 The bases of Q2 and Q3 are connected to the center points of the right and the left power amplifiers When the DC balance of the power stage is lost for some reason a potential difference is produced in the input signal to the differential amplifier and the collector currents of Q2 and Q3 are put out of balance Thus the relay driving circuit functions and the relay switch is turned off Power amplifier Fig 10 DC Voltage Detection Circuit voltage detection detection circuit circuit Relay driving circuit Fig 9 Protection Circuit 16 Over current and Overload Detection The equivalent circuit of this detector section is shown in Fig 11 and Fig 12 a shows the equiva lent circuit at the time of a positive half cycle When this equivalent circuit is overloaded the balance of the bridge formed by 1 R1 and RL is disturbed and a potential is produced between b and a in such a direction that Q1 is turned on When Q1 is turned on the collector current increases the relay driving cir
37. ertz 1 dB Tone Control BEN rs 8dB 7dB 100 Hz TREBEE M e ca cade cada os 9dB 7dB 10 kHz Filter Tar 6 kHz 6dB oct Loudness Contour Volume control set at 40dB position 6dB 100 Hz 10 kHz Hum and Noise IHF short circuited A Network rated power PROMO L a aa 70dB AUX an MERE 90dB FM Section Usable Sensitivity 10 7dBf 1 9uV 19 0dBf 9 8uV 50dB Quieting Sensitivity MOGNO 8 3 17 2dBf 4 STEREO 222242 39 2dBf 50uV Signal to Noise Ratio at 65dBf MONG 1 a E 72dB STEREO IE 67dB Distortion 65dBf 100Hz MONO 0 1596 STEREO 20 0 3 2 0 1596 STEREOD 7 0 3 6kllz MONO se DAM 0 4 Frequency Response 30Hz to 15 000Hz 73 CU 1 0dB Alternate Channel Selectivitv 80dB Spurious Response 72 24 2 90dB 727 2079 COT 80dB Iis Response 2 ARA ETT 100dB S gbression 55dB Mutii ilffeshold 14dBf 2 8uV Stereo Separation 40dB 1kHz 30dB 30Hz 15kHz Subcarrier Product Ratio 62dB SCA RejectiomRatig 7 c Ge oe tee 62dB Antenna Input 0 300 ohms balanced 75 ohms unbalanced AM Section Sensitivity IHF
38. in SOURCE position In position 1 or 2 the program source indicated by the FUNCTION selector will not be heard through speaker systems or headphones 3 CONNECTION DIAGRAM REAR VIEW Outdoor FM antenna T type FM antenna 2 indoor or outdoor 22 m Please see following section Antenna and Ground Connections for instructions regarding FM antenna connection AM ferrite antenna CAUTION SPEAKER IMPEDANCE A 8 40 OR MORE SPEAKER MORE SPEAKER ND SPEAKERS AC OUTLETS 5 SWITCHED UNSWITCHED 1 300W 120 Ground de emphasis switch For normal FM reception this switch should be set on 75uS unit is set to this when leaving factory The 25uS setting is used only when listening to FM Dolby transmissions When listening to FM Dolby transmissions it will be necessary to use NR adaptor wiich can be purchased separately More detailed instructions will be found in the sect on FM Dolby Reception ANTENNA PLACEMENT Antenna should not be placed where it will be subject to elec trical interference from motor vehicles Direction of signals 1 5 meter 5 ft above More than 4 meters 15 ft above ground Make note of the following points when choosing a location for the FM antenna e Feeder wire and cable Length should be a should be insulated at short as possible mounting point
39. increases volume of R over L channel Counterclockwise rotation increases volume of L channel over R VOLUME CONTROL For adjustment of speaker or headphone output level Level increases with clockwise rotation of knob LOUDNESS SWITCH For listening at low volume level placing this switch in the ON position will boost response in low and high frequency ranges The response of the human ear to low and high sound volumes is different At low volume levels the ear is relatively insensitive to sounds at either extreme of the frequency scale By means of the LOUDNESS switch these sounds are given additional amplification TUNING METER With the needle of the SIGNAL meter deflected to the right fine tune FM broadcast by centering needle of TUNING G ea a 100 104 106 108 imi id tr HE LE E CIT E ULL J 20 Wi xTOkHz TAPE FM MUTI NG ANCE VOLUME MUNITOR FUNCTION oer am Prono AUX MIC MODE SWITCH For selection of stereophonic or monophonic mode of playback In normal operation switch should be in STEREO position In the MONO position R and L channel signals will be mixed and sounds coming from speakers of both channels will be the same NOTE Recording stereophonically with the MODE switch in the MONO position may cause channel separation to deterio rate DUPLICATE SWITCH With switch in ON position signals recorded on one of two tape decks
40. itor Ceramic trimmer VARIABLE RESISTORS OTHERS Semi fixed 47k B C92 048 Semi fixed 4 7k B ACP 055 Semi fixed 100k B C92 047 Variable resistor BALANCE ACV 135 Variable resistor VOLUME ACV 179 OTHERS Terminal TAPE 1 AKB 027 TAPE 2 AKB 027 INPUT AKB 027 Connector socket REC PLAY AKP 011 Phone jack MIC 011 SX 750 B71 004 ABE 001 ABA 121 P 12 11 AMPLIFIER ASSEMBLY AWK 065 B 19v 35 30mA Assy 21v 33 25 36 PHONO T AMP A Mae re Raok 5 E 7 g i 455 4 gt 2 40001 Cy 00035 e 102 Tuner AF Control assembly AWE 073 ss AWK 065 6 AWK 065 b F ISK x AWK 065 circuit diagram e d 2SC1313 Parts List of Amplifier Assembly AWK 065 RESISTORS SEMICONDUCTORS Transistor Transistor Transistor Transistor 2SA725 G 2SA640 E 2SA725 G 25 640 25 1313 6 25 726 6 25 640 Carbon film Carbon film Carbon film Carbon film Carbon film Carbon film RS Ceramic Ceramic Electrolytic RD VS 154J NL RD amp VS 622 RD VS 622J RDAVS 333 RDAVS 133 RD VS 472 CCDSL 470K 50 CCDSL 100K 50 CEA 101
41. mbly AWG 046 SEMICONDUCTORS 01 TA7136P1 02 TA7136P1 Volume switch Variable resistor BASS 100 2 ACV 138 Variable resistor TREBLE 100k A2 ACV 138 Lever switch S1 TONE ASK 090 Lever switch S2 HIGH FILTER ASK 090 RESISTORS Syn Carbon film 2 2k RD PM 222 Carbon film 2 2k RD PM 222 Carbon film 180k 184 Carbon film 180k RD PS 184 Carbon film RD PS 101 Carbon film RD PS 101 Carbon film 2 7k 272 Carbon film 2 7k RD 4PM 272 Carbon film 100k 104 Carbon film 104J Carbon film Carbon film 47k Carbon film 51k Carbon film 51k Carbon film 473 473 RD PS 513 RD PS 513 RD PM 274 Carbon film Carbon film 24k Carbon film 24k Carbon film 4 3k Carbon film RD PS 274 RD 4PM 243 243 RD PM 432 432 Carbon film RD PM 103 Carbon film 10k RD PS 103 Carbon film 6 8k RD PM 682 Carbon film 6 8k RD PS 682 Carbon film RD PS 123 Carbon film RD PS 123 Carbon film 1M RD PS 105 Carbon film 1M RD PS 105 Carbon film 2k RD PS 202 Carbon film RD PS 202 CAPACITORS Symbol Demi Tee CSSA R47M 25 CSSA R47M 25 CEA 101P 6 Electrolytic Electrolytic Electrolytic SX 750
42. mounting holder Terminal strip 2P SN AKC 030 Nut M4 Screw 3x6 i ABN 013 ABA 048 Fuse holder 1P AKR 032 Ground terminal 4P 7 Screw 3x6 ABA 048 Ground terminal 4P Shield plate 4 indicated in green type cannot be supplied Heat sink Insulator wafer AEC 076 2 L 9 Screw 3x8 ABA 081 ABA 002 Connection cable housing ADX 025 Connection cable housing ADX 026 Screw 3x12 ABA 029 Transistor 2SB 541 R ransistor 2SD388 R Insulator wafer AEC 076 Screw ABA 002 Power amplifier assembly AWH 046 Connection cable housing ADX 025 114 PARTIV Parts indicated in green type cannot be supplied Main chassis Screw 3x6 Screw 3x6 ABA 048 assembly eer AWR 100 yon 47 P C Board mounting plate Wire saddle Screw 3x6 ABA 048 104 8 Screw 3x6 Fuse FU 2 f 048 107 Fuse FU 3 Power supply amp protection assembly L 9 111 AWR 099 Fuse FU 4 111 Ground terminal 2P Screw 3x6 ABA 048 di cated in green type cannot be supplied Screw 3x6 Tuner AF amp control assembly ABA 048 AWE 073 Variable resistor VOLUME ACV 179 Variable resistor BALANCE V Phone jack AKN 01 013 Knob MUTING AAD 112 Lever switch LOUDNESS ASK 090 Lever switch MODE ASK 090 Yt SX 750 Wire saddle
43. o 19kHz by a frequency divider This signal and the pilot 19kHz of the received signal are applied to a phase comparator which converts the phase differences of the two signals into a voltage The voltage is then fed back to the VCO The oscillator signal phase becomes locked to the pilot signal by this loop PLL and a 38kHz signal synchronised to the pilot signal is obtained and employed as the switching signal 2 Automatic stereo detector With the PLL locked to the pilot signal the pilot signal and a 19kHz signal of the same phase are produced A voltage is then obtained at the phase comparator that is proportional to the pilot signal amplitude As it increases the lamp lights and the switch becomes on The switching signal is applied to the demodulator 3 Demodulator This is a switching circuit employing two dif ferential amplifiers Fig 4 01 and Q2 are alternately switched on and off by the switch 1 Switching 89 signal 38kH2 7 Composit 1 signal 2 ing signal composite signal is amplified at Q3 switched and demodulated Q6 and Q3 are loosely coupled at their emitters by R1 R3 is driven in reverse phase to Q3 This is switched at Q4 and Q5 and by composing with Q1 and Q2 at the collector crosstalk becomes cancelled Adequate current flow is required to Q3 and Q6 to improve distortion figures at this point However if the base bias voltage is raised the voltage component at the colle
44. o A terminals and from speakers connected to B terminals PHONES OUTPUT 7 Insert headphone plug into this jack when headphone listening is desired In this case SPEAKERS switch should be in OFF position BASS TREBLE CONTROLS For tone adjustment when TONE switch is in ON posi tion When knobs are turned clockwise from 0 position response in bass or treble range respectively is boosted Turning counterclockwise attenuates response TONE SWITCH Controls ON OFF operation of tone control circuit In the ON position tone control by means of BASS and TREBLE knobs may be accomplished In the OFF posi tion the tone control circuit is bypassed and frequency response in high and low ranges is flat HIGH FILTER SWITCH For high frequency noise due to scratches on the record place switch in 6kHz position This will provide 6dB octave attenuation at frequencies above 6kHz For normal operation switch should be in OFF upper position SIGNAL METER For FM and AM reception turn TUNING knob until needle of the SIGNAL meter is deflected a maximum to the right STEREO INDICATOR LAMP Lights when FM stereo broadcast is being received FN m NM Uem AN 5 50 SPEAKERS OFF FOWER ETTIV ae oer U SN BALANCE CONTROL For adjustment of relative output levels of L and R channels of speaker systems or headphones Clockwise rotation from center position
45. o that lissajous pattern displayed on oscilloscope becomes stationary Fig 16 Set MPX SG to 67 5kHz deviation at 1kHz for left and right channels and to 7 5kHz deviation for 19kHz pilot signal Adjust T5 core for minimum audio frequency distortion Take care to turn core only within 180 Adjust VR3 for minimum signal leakage from R channel to L channel and from L channel to R channel Lissajous 20 Oscilloscope AC voltmeter MPX signal generator Distortion meter Fig 16 meter as shown in Fig 17 load to speaker terminals Set trol to minimum fully counter 1 VR2 shown in Fig 17 fully ise then set POWER switch to after turning on the power adjust el and VR4 R channel for dication on DC voltmeter 5 after turning on the power again RI and VR2 for 30mV indication on eter sx 750 7 DIAL CORD STRINGING 1 Remove the wooden cover and the front panel Dial Pointer Installation Caution 2 Turn tuning drum fully clockwise as viewed Metal portion of dial pointer is plated If this from X direction in Fig 18 section is touched directly by hand or fingerprint 3 Tie one end of cord to stud on inner section of 7 5 2 peri io M tuning drum more easily performed by loo wi dirt from aventurine finis ish As this is not desirable ening setscrew and temporarily removing tuning in terms of both appe ce and anticorro
46. plifier and Detector Comprise 2 dual element ceramic filters 1 tran sistor and 1 integrated circuit The IC HA1137 circuit is illustrated in Fig 2 FM IF Amplifier and Detector Circuit Three dual element ceramic filters an IC HA1201 containing a differential amplifier and an IC HA1137 containing a 3 stage limiter amplifier compose the FM IF amplifier Fig 2 shows the HA1137 block diagram see circuit diagram on page 65 In addition to limiter amplifier the HA1137 IC includes detector meter drive circuits The detec tor circuit in the HA1137 is not employed in this set however a separate ratio detector circuit is employed instead resulting in improved S N ratio AF output Fig 1 Ratio detector SIGNAL meter Block Diagram of HA1138 Diode limiter limiter amp limiter amp limiter amp Level detector y Level detector Quad limiter Fig 2 Block Diagram of HA1137 13 Multiplex Decoder Demodulation is performed by switching detection A single IC HA1196 composes the circuit which is divided into 3 sections Fig 3 shows the HA1196 block diagram see circuit diagram on page 65 1 Switching signal generator A PPL phase locked loop system is employed 76kHz is generated by a VCO voltage controlled oscillator oscillator in which the frequency is varied by a control voltage and converted int
47. s Feeder wire should be coiled Fig 1 750 VIEW Accessory AC outlets Switched Power to this outlet is controlled by the SX 750 power switch When power to the receiver is this outlet will provide AC current 100 watts maximum Unswitched Power to this outlet is not controlled by the SX 750 Power switch As long as the power cord is plugged into a live outlet this outlet will supply AC current maximum 300 watts L channel R channel A SPEAKER SYSTEMS L channel R channel Tape deck ee Cartridge tape deck B SPEAKER SYSTEMS Fig 2 4 BLOCK DIAGRAM FM TUNER 2 Mi IF amp x 7 CF HAT2001 CF 37 FM 1500 o FM 3000 GND AM Lug LL L 30 Sic Lo FIA 1 SIGNALI HA1138 2 BL ie 1 OS f CONTROL SECTION As gy E gt fi PE ond I 1 TAT7 36P OFF 9 ic I A al 2 5 x B wi IE x B SI TAI136P1 EC Ka 25 TRE PHON 5 gt RY ini OFF 4 E E pe 2 DC OF OF Jj om 524 transformer 2 POWER 7 ej AC outlet 205 A JE Se 5 al
48. sion drum from shaft 4 Route cord through tuning drum cutout make a dling the the metal section half turn around the drum then route in sequence to pulley A dial pointer pulley B pulley C 5 Wind cord 3 turns clockwise as viewed from rear panel around tuning shaft then route to pulley D 6 Wind cord two turns around tuning drum and tie to spring hook so that tension is applied to the cord 7 Turn TUNING knob and confirm normal cord motion then trim off excess cord 8 With tuning drum at step 1 setting restrain cord from moving and slip dial pointer on cord Align it with the starting point extreme left end of frequency scale Fig 18 22 Control amp Power amp 21 54 80 150mV AUX Rs 2 5mV PHONO Frequency 1kHz SX 750 9 DISASSEMBLY Top Cover Fig 19 Take out 2 screws each at left and right total 4 screws to remove Fig 19 Bottom Plate Fig 20 Take out screws 1 to remove Fig 20 Front Panel Fig 21 Pull off all knobs and remove shaft nuts of SPEAK ERS and FUNCTION switches Front panel can then be removed by taking out screws 2 amp 3 Fig 21 24 10 PARTS LOCATION 10 1 FRONT PANEL VIEW ront panel assembly ANB 421 0 PIONEER STEREO RECEIVER MODEL 5 750 Phone jack Head phone AKN 010 Knob SPEAKERS AAB 100 Knob BASS AAB 099 Knob TREBLE AAB 0
49. t socket cover 1 EXPLODED VIEW PART II 1 PART III on page 38 on page 39 Screw 3x6 ABA 048 Electrolytic capacitor 057 ast LET B Screw 42 002 lt I Screw 3x8 002 049 is Washer Scre ANF 453 Nut M11 71 005 Knob SPEAKERS FUNCTION AAB 100 Knob BASS TREBLE BLANCE 099 Knob BASS TREBLE BLANCE AAB 099 Knob VOLUME ANB 421 AAB 100 Knob TUNING Knob SPEAKERS FUNCTI AAA 036 AAB 100 Knob TONE HIGH FILTER AAD 113 1 2 3 SX 750 NOTE Parts indicated in green type cannot be supplied Wooden cabinet AMM 053 Screw 4x15 ABA 113 Screw ABA 012 111 Parts indicated in green type cannot be supplied Screw 3x8 Screw 3x6 ABA 048 Dial panel Lamp assembly AAG 114 Double meter KUN AAW 040 Tuning shaft assembly pcm hc B S AXA 124 Screw 3x6 ABA 104 Lamp with wire AEL 069 ka 3x6 Lamp with wire Spacer M9x1t ABA 048 AEL 064 Lamp holder Lamp with wire i AEB 080 AEL 069 Lamp with wire AEL 066 Lamp with wire Screw 3 6 AEL 067 ABA 048 Meter fitter 112 PART II NOTE Parts indicated in green type cannot be supplied Power transformer ATT 264 KU model ATT 301 KC model Power transformer
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