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SERVICE MANUAL

Performance Specifications ........................................ 2
Notes ......................................................................... 2
Rear Panel .................................................................. 3
Section Location ........................................................ 4
Block Diagram ...................................................... 5 - 7
Interconnection Diagram .................................... 8 - 10
Main Schematic and PCB .................................  11 - 16
Control  Schematic and PCB ............................. 17 - 20
Balanced Schematic and PCB ........................... 21 - 22
Volume/Tone Schematic and PCB ..................... 23 - 26

Data Schematic and PCB ................................... 27 - 28
Pushbutton Schematic and PCB ........................ 29 - 30
Amplifier Schematic and PCB ............................ 31 - 34
Power Supply Schematic and PCB ..................... 35 - 38
Meter Schematic and PCB ................................. 39 - 40
Backup PS Schematic and PCB ................................ 41
Terminal Schematic and PCB ................................... 42
Parts List ............................................................ 43 - 48
Exploded View and Parts List ............................. 49 - 52
Repacking Instructions ............................................. 53

CONTENTS

TUBE

INTEGRATED AMPLIFIER

Summary of Contents for MA2275

Page 1: ...Schematic and PCB 21 22 Volume Tone Schematic and PCB 23 26 Data Schematic and PCB 27 28 Pushbutton Schematic and PCB 29 30 Amplifier Schematic and PCB 31 34 Power Supply Schematic and PCB 35 38 Mete...

Page 2: ...amp output High Level 450mV for 2 5V preamp output Power Amplifier Input 2 5V for rated output A Weighted Signal To Noise Ratio Phono Input 80dB below 10mV input High Level 97dB below rated output Pow...

Page 3: ...MA2275 McINTOSH LABORATORY INC BINGHAMTON NY MADE IN USA CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN CAUTION FOR CONTINUED PROTECTION AGAINST FIRE HAZARD REPLACE ONLY WITH SAME TYPE AND RATING FUSE CD...

Page 4: ...R PCB OUTPUT TRANSFORMER 3 CONTROL PCB OUTPUT TRANSFORMER VOLUME TONE PCB 7 PUSHBUTTON PCB 8R 8L AMP PCB AMP PCB 11 BACKUP POWER SUPPLY PCB 9 POWER SUPPLY PCB 13 TERMINAL PCB 2 MAIN PCB 12 TERMINAL PC...

Page 5: ...5 7 6 MA2275 BLOCK DIAGRAM...

Page 6: ...8 10 9 1 INTERCONNECT...

Page 7: ...11 13 12 MA2275 2A MAIN 049965 SH 1 OF 2...

Page 8: ...R32 R28 C35 C36 C33 C40 C37 R41 C30 U3 C34 C1 C6 R14 C8 C12 C86 R16 C10 K21 K1 U4 R29 C68 C39 C38 C29 R33 R38 C67 R62 C56 R59 C50 R83 Q4 Q2 C65 R75 C54 C52 C55 R53 R54 R85 C74 Q1 C81 C79 D2 K7 R13 C7...

Page 9: ...17 18 MA2275 CONTROL 049966 3...

Page 10: ...6 3 R2 R5 Q2 R12 R13 C4 C5 Q1 R6 R15 R17 C2 C1 R1 R8 C3 R22 S1 DS2 DS14 DS13 DS12 JMP1 129473 U4 R11 R9 R21 R23 R19 R16 DS9 R10 DS1 DS4 Y1 J2 J1 R20 R24 R18 DS10 DS11 U1 J3 R7 U5 DS7 U3 DS15 DS6 R3 R4...

Page 11: ...BALANCED 049967 4 MA2275 21 22...

Page 12: ...23 24 VOLUME TONE 049968 5A VOLUME TONE 049968 5B...

Page 13: ...049968 5 R13 C19 R21 R22 R20 D1 R19 R24 C17 C20 R25 R6 R5 R2 C4 K1 C16 C13 R14 R15 U2 C14 K4 K2 R16 R23 129475 C11 C1 C8 C6 C3 C42 C5 C9 C12 R7 C15 R18 R4 C10 U1 R8 R3 R10 R9 R11 R12 K3 C18 J1 R53 R2...

Page 14: ...DATA 049969 6 27 28 C5 C1 C4 D3 C2 R13 R16 R14 R19 R22 R8 R7 R5 R2 R10 R20 129476 R23 R6 R3 U4 D2 U3 C3 R11 R21 D1 J8 SP1 J5 J4 J2 J7 J10 J9 R9 R4 R1 R12 R17 R15 U1 U2 R18 J6 SP2 J3 J1 J11 Rev A...

Page 15: ...1uF C1 MONO 47uF C2 5 6V IR SENSOR 5 6V 15V 5 6V 5 6V 5 6V 5 6V HDPH GND FP DATA 15V REC MON TONE MUTE REC MON TONE BYPASS MUTE STANDBY ON S4 TONE BYPASS MONO S5 100 R2 5 6V L HDPH GND R HDPH TUBE WAR...

Page 16: ...31 32 AMPLIFIER 049971 8 R L...

Page 17: ...Q7 R32 C1 R17 R14 Q2 R5 R11 R36 R7 R6 R9 R13 J3 J4 J9 Q9 R16 R37 R35 Q8 J1 R33 C10 C8 C2 C7 R8 R34 Q4 Q6 J5 J6 J2 C3 U1 C4 C11 L2 R31 R27 F1 R23 R22 Q5 Q3 R15 R12 R19 R25 129478 C6 R20 R24 C5 V1 J7 V...

Page 18: ...1 2 G D S Q6 AMP_MUTE 100k R9 14V 24V FIL_A TURN ON J5 8 J5 3 TO MAIN 15V 15V J5 2 300V 8R 8R TO R AMP J7 4 J7 3 FIL B J7 2 J7 3 400V TO BACKUP PS 4700uF C11 680uF C9 680uF C10 10uF C12 D10 3 1 2 Q2...

Page 19: ...D4 R8 Q6 Q3 R5 Q2 J3 J4 J2 J1 C5 Q1 C15 D6 D8 D9 F1 F2 C12 GP1 J18 J17 C7 R10 C6 C2 R1 J9 C14 C11 J11 J10 J14 D7 U3 U2 J8 D1 C9 J16 C3 R2 C4 C10 BLU BLU BLU BLK GRN RED RED Rev A GRN RED BLK RED BLU...

Page 20: ...METER 049973 10 39 40...

Page 21: ...41 42 MA2275 BACKUP PS 050007 11 TERMINAL 050052 12 TERMINAL 050052 13...

Page 22: ...500 OHMS 087050 K11 RELAY REED FORM 1A 5V 500 OHMS 087050 K12 RELAY REED FORM 1A 5V 500 OHMS 087050 K13 RELAY REED FORM 1A 5V 500 OHMS 087050 K16 RELAY REED FORM 1C 5V 125 OHM 087056 K17 RELAY REED F...

Page 23: ...OHM 1 1 4W 144086 R24 RES MF 1M 1 4W 144269 R25 RES MF 1K 1 1 4W 144090 R26 RES MF 1K 1 1 4W 144090 R53 RES MF 10 OHM 1 1 4W 144157 U1 IC DUAL OPERATIONAL AMPLIFIER 133260 U2 IC OPAMP NE4558N 133028 U...

Page 24: ...5MM HI INTENSITY 058166 DS2 LED GREEN 5MM HI INTENSITY 058165 DS3 LED BLUE 5MM HI INTENSITY 058166 DS4 LED GREEN 5MM HI INTENSITY 058165 DS5 LED BLUE 5MM HI INTENSITY 058166 DS6 LED GREEN 5MM HI INTE...

Page 25: ...30 29 26 11 11 11 16 18 19 17 22 21 15 14 14 13 12 11 10 9 8 10 9 8 2 7 7 6 5 4 3 1 REF 4X 3X 3X 4X 3X 4X 4X 4X 4X 9X 4X 5X 4X 3X 13X 2X 57 64 62 63 59 77 77 77 63 65 64 63 65 66 55 52 67 55 52 62 63...

Page 26: ...49 104016 WASHER INT STAR 5 X 630 X 022 50 102003 NUT MACH 6 32 W LOCK 51 084112 POST GROUND GOLD 52 100250 SCREW MACH SEMS 6 32 X 1 4 PH PN 53 049971 ASSY AMP PCB 54 049954 ASSY MAIN PCB 55 100157 S...

Page 27: ...53 MA2275 REPACKING INSTRUCTIONS...

Page 28: ...out notice Because of the constant upgrading of McIntosh products circuitry and components the Company cannot insure and does not warrant the accuracy of the within schematic material which is intende...

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