McIntosh MC-252 Service manual

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Page 1

POWER AMPLIFIER

CONTENTS

Performance Specifications ........................................ 2

Notes ......................................................................... 2

Rear Panel .................................................................. 3

Section Location ........................................................ 4

Block Diagram ...................................................... 5 - 6

Interconnection Diagram ...................................... 7 - 8

Heatsink Schematic and PCB ............................. 9 - 14

SERVICE MANUAL

Power Supply Schematic and PCB..................... 15 - 16

Input Schematic and PCB .................................. 17 - 18

Meter/Lighting Schematic and PCB .................... 19 - 21

Meter Led Schematic and PCB .......................... 21 - 22

Parts List ............................................................ 23 - 26

Exploded View and Parts List ............................. 27 - 32

Repacking Instructions ............................................. 33

Page 2

PERFORMANCE SPECIFICATIONS

Power Output Stereo

250 watts into a 2, 4 or 8 ohm load is the minimum sine wave continuous average power per channel with both channels operating

Power Output Mono Bridged

500 watts into a 4, 8 or 16 ohm load is the minimum sine wave continuous average power output

Power Output Mono Bi-Amp

500 watts into a 1, 2 or 4 ohm load is the minimum sine wave continuous average power output

Output Load Impedance

Stereo: 2, 4 or 8 ohms Mono: 1, 2, 4, 8, or 16 ohms

Rated Power Band

20Hz to 20,000Hz

Total Harmonic Distortion

Maximum Total Harmonic Distortion at any power level from 250 milliwatts to rated power output is 0.005%

Intermodulation Distortion

Maximum Intermodulation Distortion if instantaneous peak output per channel does not exceed twice the rated output, for any combination of frequencies from 20Hz to 20,000Hz, with all channels operating is 0.005%

Dynamic Headroom

2.0dB

Sensitivity

1.6 Volts Unbalanced Input

3.2 Volts Balanced Input

A-Weighted Signal To Noise Ratio

112dB below rated output

Input Impedance

10,000 ohms

Wide Band Damping Factor

Greater than 40

Power Requirements

100 Volts, 50/60Hz at 8 amps 110 Volts, 50/60Hz at 7.2 amps 120 Volts, 50/60Hz at 6.6 amps 220 Volts, 50/60Hz at 3.3 amps 230 Volts, 50/60Hz at 3.3 amps 240 Volts, 50/60Hz at 3.3 amps

Note: Refer to the rear panel of the MC252 for the correct voltage.

Overall Dimensions

17-1/2 inches (44.45cm) W , 9-7/16 inches (23.97cm) H, 14-3/4 inches (37.5cm) D, including clearance for connectors

Weight

94.5 pounds (207.9kg) net, 108.5 pounds (238.7kg) in shipping carton

Frequency Response

+0, -0.25dB from 20Hz to 20,000Hz +0, -3dB from 10Hz to 100,000Hz

NOTES

1. The heavy notes on the schematic denote the primary

signal path.

2. Unless otherwise noted, all voltages indicated on the schematics are measured under the following conditions: a. AC input at 120 volts, 50/60Hz. b. All voltages are +/-10% with respect to ground. A

high impedance (10 megaohm) voltmeter must be used.

3 . Unless otherwise specified:

a. Resistor values are in ohms. b. Capacitor values are microfarads (uF). c. Inductor values are in microhenries (uH).

4 . On PC board drawings, Square pad indicates:

a. Polarized Capacitors - Positive b. Diodes - Cathode c. Others - Pin 1

5. WARNING

Parts marked with the symbol have critical characteristics. Use only replacement parts recommended by the manufacturer.

Page 3

TOP AND REAR PANEL

MC252

Page 4

SECTION LOCATIONS

TOP VIEW WITH COVER REMOVED

BOTTOM VIEW WITH COVER REMOVED

Page 5

BLOCK DIAGRAM

MC252

5 6

Page 6

INTERCONNECT

7 8

Page 7

MC252

HEATSINK 049986

DRIVER SECTION

9 10

Page 8

2A 2B

HEATSINK 049986

HEATSINK SECTION

11 12

Page 9

MC252

2A 2B

HEATSINK 049986

13 14

Page 10

POWER SUPPLY 049757

15 16

Page 11

MC252

INPUT 049755

17 18

Page 12

METER/LIGHTING 049756

19 20

Page 13

MC252

METER/LIGHTING 049756

METER LED 049758

21 22

Page 14

PARTS LIST

Ref. No. Description Part No.

INTERCONNECT

BP1 Binding Post BLK 117741 BP2 Binding Post RED 117741 BP3 Binding Post RED 117741 BP4 Binding Post RED 117741 BP5 Binding Post RED 117741 BP6 Binding Post RED 117741 BP7 Binding Post RED 117741 BP8 Binding Post BLK 117741 D1 Diode Bridge Rectifier 070139 F1 Fuse 089105 J1 Receptacle, AC Line 117487 MT1 Meter 124084 MT2 Meter 124084 RT1 Thermistor Assembly 052008 RT2 Thermistor Assembly 052008 S1 Switch 146243 S2 Switch 146243 T1 Power Transformer 049763 T2 Output Transformer 049766 T3 Output Transformer 049766 TB1 Terminal Block AC 074091

049986 HEATSINK

C1 CAP DISC MONO .47UF 50V 061249 C2 CAP MONO .1uF 50V 20% Z5U 061305 C3 CAP MONO .1uF 50V 20% Z5U 061305 C4 CAP ELECT 47UF 35V 066446 C5 CAP ELECT 10UF 100VDC 066462 C6 CAP ELECT 10UF 100VDC 066462 C7 CAP MONO .1uF 50V 20% Z5U 061305 C8 CAP MONO .1uF 50V 20% Z5U 061305 C9 CAP MONO 220PF 100V 10PO 061301 C10 CAP MONO 100PF 100V 10% NPO 061300 C11 CAP MONO 100PF 100V 10% NPO 061300 C12 CAP ELECT 220UF 25V 066507 C13 CAP MPF 0.0047UF 5VDC 064308 C14 CAP POLYPROP 0.15UF 10VDC 064363 C15 CAP POLYPROP .047UF 10VDC 064364 C16 CAP ELECT 10UF 100VDC 066462 C17 CAP ELECT 10UF 100VDC 066462 C18 CAP MONO .01UF 50V 20% X7R 061304 C19 CAP ELECT 47UF 35V 066446 C20 CAP ELECT 47UF 35V 066446 C21 CAP MONO .01UF 50V 20% X7R 061304 C22 CAP MONO .1uF 50V 20% Z5U 061305 C23 CAP MONO 100PF 100V 10PO 061300 C24 CAP MONO 100PF 100V 10% NPO 061300 C25 CAP MONO .1uF 50V 20% Z5U 061305 C26 CAP MPF 0.47UF 5/100VDC 064442 C27 CAP MPF 0.47UF 5/100VDC 064442 D1 DIODE SILICON 070047 D2 DIODE SILICON 070047 D3 DIODE SILICON 070047 D4 DIODE SILICON 070047 D5 DIODE SILICON 070047 D6 DIODE 200V 3A 070126 D7 DIODE 200V 3A 070126 J1 CONN MALE 9 POS FRICTION LK 117244 J2 CONN MALE 9 POS FRICTION LK 117244 J3 CONN HEADER 2 PIN 0.156 117404 J4 BLADE FASTON W/FEET 117708 J5 CONN 4 PIN 117215 J7 BLADE FASTON W/FEET 117708

J8 CONN 2 PIN MALE 117213 J9 BLADE FASTON W/FEET 117708 LD1 LDR NETWORK VTL5C9 144179 Q1 TRANSISTOR PNP 132224 Q2 TRANSISTOR NPN 132223 Q3 TRANSISTOR NPN 132223 Q4 TRANSISTOR N JFET 132222 Q5 TRANSISTOR N JFET 132222 Q6 TRANSISTOR N JFET 132222 Q7 TRANSISTOR NPN POWER 132255 Q8 TRANSISTOR SI NPN 25V 132254 Q9 TRANSISTOR NPN POWER 132255 Q10 TRANSISTOR PNP 132224 Q11 TRANSISTOR NPN POWER 132255 Q12 TRANSISTOR SI NPN 25V 132254 Q13 TRANSISTOR NPN 132223 Q14 TRANSISTOR SI NPN 25V 132254 Q15 TRANSISTOR NPN 132223 Q16 TRANSISTOR PNP 132224 Q17 TRANSISTOR NPN 25C3334C 132285 Q18 TRANSISTOR PNP 2SA32IC 132286 Q19 TRANSISTOR NPN SILICON 132171 Q20 TRANSISTOR PNP SILICON 132172 Q21 TRANSISTOR NPN 132223 Q22 TRANSISTOR NPN 25C3334C 132285 Q23 TRANSISTOR PNP 2SA32IC 132286 Q24 TRANSISTOR NPN 132268 Q25 TRANSISTOR PNP 132267 Q26 TRANSISTOR NPN POW 2SC5200 132291 Q27 TRANSISTOR PNP POW 2SA1943 132292 Q28 TRANSISTOR NPN POW 2SC5200 132291 Q29 TRANSISTOR PNP POW 2SA1943 132292 Q30 TRANSISTOR NPN POW 2SC5200 132291 Q31 TRANSISTOR PNP POW 2SA1943 132292 Q32 TRANSISTOR NPN POW 2SC5200 132291 Q33 TRANSISTOR PNP POW 2SA1943 132292 Q34 TRANSISTOR NPN POW 2SC5200 132291 Q35 TRANSISTOR PNP POW 2SA1943 132292 R1 RES MF 10 OHM 1% 1/4W 144157 R2 RES MF 10 OHM 1/4W R3 RES MF 4.75K 1% 1/4W 144097 R4 RES MF 100 OHM 1% 1/4W 144196 R5 RES MF 475 OHM 1% 1/4W 144086 R6 RES MF 22.1K 1% 1/4W 144187 R7 RES MF 10M 1% 1/4W 144264 R8 RES MF 267K 1% 1/4W 144118 R9 RES MF 2.21K 1% 1/4W 144298 R10 RES MF 221 OHM 1% 1/4W 144172 R11 RES MF 267K 1% 1/4W 144118 R12 RES MF 47.5K 1% 1/4W 144108 R13 RES MF 47.5K 1/4W 144108 R14 RES MF 3.32K 1% 1/4W 144095 R15 RES MF 221 OHM 1% 1/4W 144172 R16 RES MF 1K 1% 1/4W 144090 R17 RES MF 221 OHM 1% 1/4W 144172 R18 RES MF 3.32K 1/4W 144095 R19 RES MF 221 OHM 1% 1/4W 144172 R20 RES MF 1K 1% 1/4W 144090 R21 RES MF 221 OHM 1% 1/4W 144172 R22 RES MF 499 OHM 1% 1/4W 144087 R23 RES MF 267K 1% 1/4W 144118 R24 RES MF 187K 1% 1/4W 144406 R25 RES MF 324 OHM 1% 1/4W 144338 R26 RES MF 324 OHM 1% 1/4W 144338 R27 RES MF 6.49K .5% 1/4W 144401 R28 RES MF 13.7K 1% 1/4W 144342 R29 RES MF 221 OHM 1/4W 144172 R30 RES WW 2 OHM 10% 5W 139005

144157

R31 RES WW 4 OHM 5W 139119 R32 RES FP 22 OHM 1/4W 5 137033 R33 RES FP 22 OHM 1/4W 5 137033 R34 RES MF 324 OHM 1/4W 144338 R35 RES MF 324 OHM 1/4W 144338 R36 RES MF 2.21K 1/4W 144298 R37 RES MF 22.1K 1/4W 144187 R39 RES MF 22.1K 1/4W 144187 R40 RES MET OX 680 OHM 5% .5W 137093 R41 RES MET OX 680 OHM 5% .5W 137093 R42 RES MF 1.82K 1% 1/4W 144296 R43 RES MET OX 430 OHM 5% .5W 137095 R44 POT TRIM 200 OHM 20% HORIZ AD 134390 R45 RES MF 1.82K 1% 1/4W 144296 R46 RES MET OX 47 OHM 5% .5W 137096 R47 RES WW DUAL .47 OHM 5% 5W 139199 R48 RES WW DUAL .47 OHM 5% 5W 139199 R49 RES WW DUAL .47 OHM 5% 5W 139199 R50 RES WW DUAL .47 OHM 5% 5W 139199 R51 RES WW DUAL .47 OHM 5W 139199 R52 RES MF 1K 1% 1/4W 144090 R53 RES MF 1K 1% 1/4W 144090 R54 RES WW DUAL .47 OHM 5W 139199 R55 RES WW DUAL .47 OHM 5% 5W 139199 R56 RES WW DUAL .47 OHM 5% 5W 139199 RT1 SENSOR THERMAL 144249 U1 IC OPAMP NE4558N 133028

049757 POWER SUPPLY

C1 CAP POLY .047UF 10% 250VDC 064364 C2 CAP ELECT 10UF 50V 066445 C3 27000uF 100V ELECTROLYTIC 066489 C4 27000uF 100V ELECTROLYTIC 066489 C5 CAP ELECT 22UF 100V 066506 C6 CAP ELECT 3300UF 35V 066509 C7 CAP ELECT 3300UF 35V 066509 C8 CAP ELECT 4.7UF 50V 066512 C9 CAP ELECT 10UF 100VDC 066462 D1 DIODE RECTIFIER 070131 D2 DIODE RECTIFIER 070131 D3 DIODE RECTIFIER 070131 D4 DIODE RECTIFIER 070131 D5 DIODE RECTIFIER 070131 D6 DIODE RECTIFIER 070131 D7 DIODE SILICON 070047 HS1 HEATSINK T0220 080014 HS2 HEATSINK T0220 080014 J1 BLADE FASTON W/FEET 117708 J2 BLADE FASTON W/FEET 117708 J3 BLADE FASTON W/FEET 117708 J4 BLADE FASTON W/FEET 117708 J5 BLADE FASTON W/FEET 117708 J6 BLADE FASTON W/FEET 117708 J7 CONN MALE 7 PIN 117217 J8 CONN 4 PIN 117215 J9 BLADE FASTON W/FEET 117708 J11 CONN HEADER 2 PIN 0.156 117404 J12 CONN HEADER 2 PIN 0.156 117404 J13 BLADE FASTON W/FEET 117708 J14 CONN MALE 9 POS FRICTION LK 117244 J15 CONN MALE 9 POS FRICTION LK 117244 J16 CONN MALE 9 POS FRICTION LK 117244 J17 BLADE FASTON W/FEET 117708 J18 BLADE FASTON W/FEET 117708 K1 RELAY 48V 18.8mA 87052 Q1 TRIAC DRIV OPTOCPLR 600V 131022 Q2 TRANSISTOR NPN 132223 Q3 TRANSISTOR PNP 132224

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Page 15

MC252

PARTS LIST con’t

Q4 TRANSISTOR NPN 132223 Q5 TRANSISTOR PNP 132224 Q6 TRANSISTOR P CHAN JUNC FET 132226 Q7 TRANSISTOR PNP 132224 R1 RES MF 33.2K 1% 1/4W 144015 R2 RES MF 33.2K 1% 1/4W 144015 R3 RES MF 2.74M 1/4W 144271 R4 RES WW 1.5K 10% 5W 139079 R5 RES MF 1.1K 1% 1/4W 144091 R6 RES MF 22.1K 1% 1/4W 144187 R7 RES MF 1M 1/4W 144269 R8 RES MF 12.1K 1% 1/4W 144154 R9 RES MF 2.1K 1% 1/4W 144299 R10 RES MF 12.1K 1% 1/4W 144154 R11 RES MF 3.32K 1% 1/4W 144095 R12 RES MF 20K 1% 1/4W 144104 R13 RES MF 2.1K 1% 1/4W 144299 R14 RES MF 150K 1% 1/4W 144419 R15 RES WW 2.7 OHM 10W 139173 R16 RES WW 2.7 OHM 10W 139173 SP1 BRACKET PCB CARD MOUNTING 003611 SP2 BRACKET PCB CARD MOUNTING 003611 SP3 BRACKET PCB CARD MOUNTING 003611 SP4 BRACKET PCB CARD MOUNTING 003611 U1 IC REGULATOR 15V 133154 U2 IC REGULATOR -15V 133153

049755 INPUT

C1 CAP ELECT 10UF 50V 066445 C2 CAP ELECT 10UF 50V 066445 C3 CAP ELECT 10UF 50V 066445 C4 CAP ELECT 10UF 50V 066445 C5 CAP MONO 47PF 200V 10% NPO 061299 C6 CAP MONO 22PF 200V 10% NPO 061298 C7 CAP MONO 47PF 200V 10% NPO 061299 C8 CAP MONO 22PF 200V 10% NPO 061298 C9 CAP MONO 22PF 200V 10% NPO 061298 C10 CAP MONO 22PF 200V 10% NPO 061298 C11 CAP MONO .1uF 50V 20% Z5U 061305 C12 CAP ELECT 10UF 50V 066445 C13 CAP MPF 0.22UF 5% 63VDC 064329 C14 CAP MONO .1uF 50V 20% Z5U 061305 C15 CAP MONO .1uF 50V 20% Z5U 061305 J1 XLR FEM HORIZ PCB WITH LATCH 117814 J2 XLR FEM HORIZ PCB WITH LATCH 117814 J3 JACK PHONO GOLD PJ261G 117436 J4 JACK HEADPHONE DUAL BLK 1/8 117825 J5 CONN MALE 9 POS FRICTION LK 117244 J6 CONN MALE 9 POS FRICTION LK 117244 R1 RES MF 20K 1% 1/4W 144104 R2 RES MF 20K 1% 1/4W 144104 R3 RES MF 20K 1% 1/4W 144104 R4 RES MF 20K 1% 1/4W 144104 R5 RES MF 20K 1% 1/4W 144104 R6 RES MF 20K 1% 1/4W 144104 R7 RES MF 20K 1% 1/4W 144104 R8 RES MF 20K 1% 1/4W 144104 R9 RES MF 40.2K 1% 1/4W 144107 R10 RES MF 40.2K 1% 1/4W 144107 R11 RES MF 20K 1% 1/4W 144104 R12 RES MF 40.2K 1% 1/4W 144107 R13 RES MF 1K 1% 1/4W 144090 R14 RES MF 20K 1% 1/4W 144104 R15 RES MF 1K 1% 1/4W 144090 R16 RES MF 40.2K 1% 1/4W 144107

R17 RES MF 20K 1% 1/4W 144104 R18 RES MF 20K 1% 1/4W 144104 R19 RES MF 3.32K 1% 1/4W 144095 R20 RES MF 3.32K 1% 1/4W 144095 R21 RES MF 20K 1% 1/4W 144104 R22 RES MF 100 OHM 1% 1/4W 144196 R23 RES MF 68.1 OHM 1% 1/4W 144082 R24 RES MF 1M 1/4W 144269 R25 RES MF 20K 1% 1/4W 144104 R26 RES MF 10 OHM 1% 1/4W 144157 R27 RES MF 10 OHM 1% 1/4W 144157 S1 JSA4320-0201 148069 SP1 BRACKET PCB CARD MOUNTING 003611 U1 IC OPAMP NE4558N 133028 U2 IC NAND SCHMIT 2-IN X 4 133192 U3 IC REGULATOR +5 VOLT 133093

049756 METER/LIGHTING

C4 CAP MONO .1uF 50V 20% Z5U 061305 C5 CAP MONO .1uF 50V 20% Z5U 061305 C8 CAP MPF 0.22UF 5% 63VDC 064329 C9 CAP MPF 0.1UF 100V 064337 C10 CAP ELECT 10UF 50V 066445 C11 CAP MONO .1uF 50V 20% Z5U 061305 C12 CAP MONO .1uF 50V 20% Z5U 061305 C13 CAP MPF 0.22UF 5% 63VDC 064329 C14 CAP MPF 0.1UF 100V 064337 C15 CAP ELECT 10UF 50V 066445 D1 DIODE ZENER 8.2V 1/2W 070130 D9 LED AMBER 058133 D13 LED AMBER 058133 D14 DIODE SILICON 070047 D15 DIODE SILICON 070047 D16 DIODE SILICON 070047 D17 DIODE SILICON 070047 D18 DIODE SILICON 070047 D19 DIODE SILICON 070047 D20 DIODE SILICON 070047 D21 DIODE SILICON 070047 D22 DIODE SILICON 070047 D23 DIODE SILICON D24 DIODE SILICON 070047 D25 DIODE SILICON 070047 DS5 LED GREEN 5MM HI-INTENSITY 058165 DS6 LED GREEN 5MM HI-INTENSITY 058165 DS7 LED GREEN 5MM HI-INTENSITY 058165 DS8 LED SQUARE RED 058109 J1 CONN MALE 9 POS FRICTION LK 117244 J2 CONN 4 PIN 117215 J3 CONN 3 POS MLE MTS100 NORM 117214 J4 HEADER 2 PIN LATCHING 117766 J5 CONN 4 PIN 117215 J6 HEADER 2 PIN LATCHING 117766 Q1 TRANSISTOR NPN 132223 Q2 TRANSISTOR NPN 132223 Q3 TRANSISTOR NPN 132223 Q4 TRANSISTOR NPN 132223 Q8 TRANSISTOR NPN 132223 Q9 TRANSISTOR NPN 132223 Q10 TRANSISTOR NPN 132223 Q11 TRANSISTOR NPN 132223 Q12 TRANSISTOR NPN 132223 Q13 TRANSISTOR NPN 132223 Q14 TRANSISTOR NPN 132223 Q15 TRANSISTOR NPN 132223 R6 RES MF 187K 1% 1/4W 144406 R8 RES MF 12.1K 1% 1/4W 144154 R9 RES MF 475K 1% 1/4W 144364

070047

R11 RES MF 4.75K 1% 1/4W 144097 R13 RES MF 681 OHM 1% 1/4W 144195 R18 RES MF 12.1K 1% 1/4W 144154 R19 RES MF 4.75K 1% 1/4W 144097 R28 RES MF 562 OHM 1/4W 144408 R29 RES MF 806 OHM 1/4W 144089 R37 RES MF 187K 1% 1/4W 144406 R38 RES MF 681 OHM 1% 1/4W 144195 R39 RES MF 475K 1% 1/4W 144364 R40 RES MF 200K 1/4W 144117 R41 RES MF 10.2K 1% 1/4W 144130 R42 RES MF 10M 1% 1/4W 144264 R43 RES MF 2.21M 1/4W 144265 R44 RES MF 100 OHM 1% 1/4W 144196 R45 RES MF 187K 1% 1/4W 144406 R46 RES MF 1.21K 1% 1/4W 144191 R47 RES 82.5K 1/4W 144112 R48 POT TRIM 100K OHM 20% 134383 R49 RES MF 221K 1% 1/4W 144421 R50 RES MF 6.81K 1/4W 144297 R51 RES MF 100 OHM 1% 1/4W 144196 R53 RES MF 200K 1/4W 144117 R54 RES MF 10.2K 1% 1/4W 144130 R55 RES MF 10M 1% 1/4W 144264 R56 RES 82.5K 1/4W 144112 R57 RES MF 2.21M 1/4W 144265 R58 RES MF 187K 1% 1/4W 144406 R59 RES MF 6.81K 1/4W 144297 R60 POT TRIM 100K OHM 20% 134383 R61 RES MF 1.21K 1% 1/4W 144191 U1 IC DUAL OPERATIONAL AMP 133260 U2 IC DUAL OPERATIONAL AMP 133260

049758 METER LED

DS1 LED BLUE 5MM HI-INTENSITY 058166 DS2 LED BLUE 5MM HI-INTENSITY 058166 DS3 LED GREEN 5MM HI-INTENSITY 058165 DS4 LED GREEN 5MM HI-INTENSITY 058165 DS5 LED BLUE 5MM HI-INTENSITY 058166 DS6 LED BLUE 5MM HI-INTENSITY 058166 DS7 LED GREEN 5MM HI-INTENSITY 058165 DS8 LED GREEN 5MM HI-INTENSITY 058165 J1 CONN 4 PIN RIGHT ANGLE 117240 R1 RES MF 221 OHM 1% 1/4W 144172 R2 POT TRIM 500 OHM 20% HOR ADJ 134410 R3 RES MF 221 OHM 1% 1/4W 144172 R4 POT TRIM 500 OHM 20% HOR ADJ 134410 R5 RES MF 221 OHM 1% 1/4W 144172 R6 POT TRIM 500 OHM 20% HOR ADJ 134410 R7 RES MF 221 OHM 1% 1/4W 144172 R8 POT TRIM 500 OHM 20% HOR ADJ 134410

25 26

Page 16

EXPLODED VIEW

2827

Page 17

EXPLODED VIEW con’t

MC252

3029

Page 18

EXPLODED VIEW PARTS LIST

Ref No.

1 016469 GLASS CENTER PANEL 2 016487 GLASS P ANEL W/HOLE 3 018717 END CAP 4 018711 CENTER EXTRUSION 5 018710 TOP/BOTTOM END CAP 6 049321 ASSY KNOB 7 104164 WASHER BLK FEL T 1 X 1 /4 X 1/16 8 094016 TAPE FOAM 1/4 X 1/8 9 100342 SCREW 6-32 X 3/8 FILLISTER HD 10 092426 FILTER COLOR METER 11 005351 GLASS PANEL, PLA TE 12 005312 PLATE GAP 13 101074 SCREW TAPPING 4-40 X 1/4 PH PN 14 100276 SCREW MACH SEMS 6-32 X 5/16 PH PN 15 005237 TITLE MOUNT 16 017913 LOGO BACKLIGHT 17 094430 TAPE FOAM WHITE 1/2W X 1/8 THK 18 101054 SCREW T APTITE 6-32 X 1/4 PH PN 19 017901 LOGO PUSHBUTTON BACKLIGHT 20 005239 SUBPANEL 21 146243 SWITCH POWER 22 021159 BUSHING SWITCH 23 021030 SPACER 6 X 1/4 24 049756 ASSY METER/LIGHTING PCB 25 102001 NUT KEP 4-40 CADMIUM PLATE 26 124084 METER 27 017881 BACKLIGHT METER 28 005229 METER PLA TE 29 102045 NUT KEP 6-32 SPECIAL 30 049758 ASSY METER LED PCB 31 104014 WASHER INT ST AR 3/8 X .507 X .002 32 005236 DUST COVER 33 100200 SCREW MACH 10-32 X 1/2 PH TRS HD 34 126948 DECAL TOP COVER 35 005234 CHASSIS 36 078025 GROMMET RUBBER 3/4ID 37 117741 POST BINDING BLK 38 117740 POST BINDING RED 39 178161 HOLDER FUSE 5 X 20mm IEC 40 117487 RECEPTACLE AC LINE 41 100250 SCREW MACH SEMS 6-32 X 1/4 PH PN 42 101197 SCREW HI-LO 4-24 X 3/8 PH HD BLK 43 049755 ASSY INPUT PCB 44 018690 HEA TSINK 45 084206 ISOSTRATE

Part No.

Description

46 112087 SPACER PCB 1/4 47 114141 CLIP RIGHT ANGLE 48 101059 SCREW SM 6 X 5/8 PH PN TYPE A 49 049986 ASSY HEA TSINK PCB 50 005235 HEATSINK COVER 51 049766 POTTED TRANSFORMER OUTPUT 52 049763 POWER TRANSFORMER POWER 53 126946 DECAL OUTPUT TRANSFORMER 54 126947 DECAL POWER TRANSFORMER 55 101078 SCREW T AP 8-32 X 5/16 PH PN BLK 56 102006 NUT MACH 10-32 W/LOCK 57 101176 SCREW TC 6-32 X 1/2 PH PN TYPE F 58 102005 NUT MACH 8-32 W/LOCK 59 102003 NUT MACH 6-32 W/LOCK 60 104005 WASHER FLAT STEEL 6 X 3/8 X .032 61 070139 DIODE BRIDGE RECTIFIER 62 084135 THERMAL P AD 63 017452 KLIP WIRE 64 104016 WASHER INT ST AR .5 X .630 X .022 65 102052 NUT GOLD SUPPLIED W/117758 66 104162 WASHER LOCK INTERNAL TOOTH 67 102051 NUT HEX M9 X .75 GOLD PLA TED 68 005240 HEA TSINK VENT 69 049757 ASSY POWER SUPPL Y PCB 70 005238 CHASSIS SUPPORT BRACKET 71 005308 CAPACITOR STRAP 72 094391 TAPE FOAM 1/8 X 3/4 3M #4508 73 074091 TERMINAL BLOCK AC 74 104001 WASHER FLAT STEEL 4 X 9/32 X .025 75 104004 WASHER LOCK 5 X .255 INT STAR 76 102022 NUT MACH 4-40 X 3/16 X 1/16 77 005242 BOTTOM COVER 78 106007 SPRING CLIP LA TCH TYPE 79 017218 FOOT PLASTIC BLK 80 104080 WASHER FEL T #10 CLEAR ZINC 81 100159 SCREW MACH 10-32 X 3/4 PH PN BLK 82 100188 SCREW MACH SEMS 10-32 X 3/8 83 066489 CAP ELECT 2700uF 100V 84 101172 SCREW TC 6-32 X 1/4 PH FL U/C 85 094429 TAPE FOAM 1/32 THK

3231

Page 19

REPACKING INSTRUCTIONS

MC252

Page 20

POWER AMPLIFIER

SERVICE MANUAL

The continuous improvement of its products is the policy of McIntosh Laboratory Incorporated, who reserve the right to improve design without 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 intended for information only.

McINTOSH LABORATORY, INC., 2 CHAMBERS STREET, BINGHAMTON, NEW YORK 13903 Printed in U.S.A. Part Number 040880