4.2 Volts Balanced 240V ~ 50/60Hz at 6 Amps 2.1 Volts Unbalanced Standby: less than 0.5 watt Note: Refer to the rear panel of the MC452 for the correct Signal To Noise Ratio (A-Weighted) voltage. 95dB Balanced (122dB below rated output)
BLOCK DIAGRAM POSITIVE CURRENT LIMITER POWER DIFF VOLTAGE CURRENT INDICATOR PREDRIVER DRIVER TRANSDUCER GUARD OUTPUT CURRENT ThermalTrak CURRENT SOURCE DC BIAS UNBALANCED VOLTAGE DIFF INPUT PREDRIVER DRIVER OUTPUT RECTIFIER METER UNBALANCED OUTPUT THERMAL LEFT NEGATIVE VOLTAGE SENSORS METER OUTPUT CURRENT HOLD SWITCH LIMITER...
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MC452 INTERCONNECT MC452 TRANSFORMER WIRING AND FUSE REPLACEMENT (CONTACT MCINTOSH FOR CURRECT TRANSFORMER P/N) Voltage BLK BLK/GRY GRY VIO WHT/VIO BRN 1 BRN 2 Jumper Location (JMP1) Main Fuse (F1) T15AH250V T15AH250V T15AH250V WHT 24 AWG WHT 18 AWG TERMINAL...
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MAIN 751134 SCH 1 of 3 +15V PC OUTPUT +15V +15V DRIVER 13.2V MODE MODE J26:1 MUTE J21:5 MUTE -18V +15V J26:5 +15V L PG LT J21:1 -15V J26:7 -15V +15V J21:3 +15V PC OUT J26:3 PC OUTPUT PC OUT DELAY -15V J21:4...
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MC452 MAIN 751134 SCH 2 of 3 +14VML U8:1 -5VML 150k L METER DRIVER -5VML +14VML +14VML U8:2 1000µF HS OUT J29:1 18.2k U10:2 AUTOF J29:2 L METER LOG AMP +15V +14VML 47 .5 W HOLD L 200k J32:1 MET [+]...
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MAIN 751134 SCH 3 of 3 J1:1 J1:4 PRIMARY J1:7 J1:10 J2:10 J2:1 J2:4 J3:2 TEST ONLY ON/OFF NO CONNECTION APPLY 12VDC TO ENERGIZE RELAYS W ITH NO AC POWER J3:1 47.5K T° AC F AC DET PWR RLY AC DETECTOR REFER TO +15V CONNECTION...
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HEATSINK 751152 SCH 1 of 2 +V AMP 47 .5 W DIFFERENTIAL VOLTAGE J1:4 100µF PG ATT J1:5 PG ATT FB COM J1:1 FB COM DRV + 1.8V J1:3 2.21M -18V 2.21M AMP MUTING CURRENT SOURCE FB 8 J2:3 J2:5 FEEDBACK NETW ORK FB 2 J2:1...
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MC452 HEATSINK 751152 SCH 2 of 2 +V AMP 1.8V DRV + DRIVER 1.2V Q28:1 CURRENT Q30:1 OUTPUTS LIM ITER Q32:1 Q34:1 BIAS ADJUSTMENT ADJUST R52 FOR 21-25 mV DC ACROSS J5 WITH NO INPUT SIGNAL AND HEATSINKS COOL Q36:1...
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MC452 LEFT TERMINAL 751138 SCH LEFT OUTPUTS J8:6 L (+) L + FB8 FB 8 J8:7 J8:5 L (+) L + FB2 FB 2 J8:2 L (-) L - FB8 FB 8 J8:3 J8:1 L (-) L - FB2 FB 2...
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MC452 RIGHT TERMINAL 751222 SCH BREAKAWAY J8:6 R (+) R + FB8 FB 8 J8:7 J8:5 R (+) R + FB2 FB 2 R (-) J8:2 R - FB8 FB 8 J8:3 J8:1 R (-) R - FB2 FB 2...
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MC452 DISPLAY/METER LIGHT 751139 SCH J5:1 J7:8 POWER J5:3 J7:10 J5:5 J7:12 FP OFF J1:7 FP OFF DISPLAY FP ON J1:4 FP ON J1:1 R INTENSITY R COLOR J5:2 J7:7 J5:4 J7:9 R BLU R BLU J5:6 J7:11 R GRN...
DIODE SMALL SIGNAL 4148 SMD 070199 ASSY AUTOFORMER POTTED 751170 DIODE SMALL SIGNAL 4148 SMD 070199 CONTACT McINTOSH SERVICE DEPT DIODE SMALL SIGNAL 4148 SMD 070199 DIODE SMALL SIGNAL 4148 SMD 070199 MAIN PCB 751134 DIODE SMALL SIGNAL 4148 SMD...
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PARTS LIST (Cont’d.) MAIN PCB 751134 (Cont’d.) Ref. No. Description Part No. Ref. No. Description Part No. RES SMD0805 100K 1/8W 1% 145014 DIODE SMALL SIGNAL 4148 SMD 070199 RES POLYSWITCH RXE110 144671 DIODE SMALL SIGNAL 4148 SMD 070199 RES POLYSWITCH RXE110 144671 HEADER SHROUDED 10 PIN 2MM 117973...
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MC452 PARTS LIST (Cont’d.) MAIN PCB 751134 (Cont’d.) Ref. No. Description Part No. Ref. No. Description Part No. CAP 100PF 50V SMD0805 061316 RES MF 12.1K 1% 1/4W 144550 CAP 47PF 200V 10% SMD0805 061368 RES MF 200K 1% 1/4W 144531 CAP MONO .1UF 50V 20% SMD0805...
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PARTS LIST (Cont’d.) RIGHT IMPUT PCB 751221 (Cont’d.) Ref. No. Description Part No. Ref. No. Description Part No. TRANSISTOR N JFET 132319 STANDOFF 6-32 X 1/4 PCB MOUNT 112130 IC DUAL OP AMP 5532 SMD 133718 (GP1) SCR SM6-18X5/8 PH PAN 401059 IC OP AMP DIFFERENTIAL SMD 133772...
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MC452 PARTS LIST (Cont’d.) HEATSINK ASSY 751152 (Cont’d.) Ref. No. Description Part No. Ref. No. Description Part No. (Q31) CLIP TRANSISTOR 214 414119 RES MO 47 OHM .5W 5% 137102 TRANS NPN 260V THERM TRAK NJL3281D 132330 RES MO 47 OHM .5W 5%...
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PARTS LIST (Cont’d.) LEFT TERMINAL PCB 751138 (Cont’d.) Ref. No. Description Part No. Ref. No. Description Part No. RES WW 4 OHM 5% 5W 139248 CONN 12 PIN FFC SMD 118001 RES WW 4 OHM 5% 5W 139248 CONN 12 PIN FFC SMD 118001 PCB1 PC BD DISPLAY...
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MC452 PARTS LIST (Cont’d.) DISPLAY/METER LIGHT PCB 751139 (Cont’d.) Ref. No. Description Part No. Ref. No. Description Part No. RES SMD0805 1.5K 1/8W 1% 145022 RES SMD0805 221 1/8W 1% 145001 RES SMD0805 1.5K 1/8W 1% 145022 IC SINGLE NAND SCHMITT SMD...
If a shipping carton or any of the interior 401212 1/4 - 20x2-1/4 cap screw part(s) are needed, please call or write Customer 104058 Flat washer Service Department of McIntosh Laboratory. Refer to page 3. Please see the Part List for the correct part numbers.
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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.
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