File name McIntosh-MC252 pwramp.pdfPOWER 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 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
SERVICE MANUAL
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 Frequency Response +0, -0.25dB from 20Hz to 20,000Hz +0, -3dB from 10Hz to 100,000Hz 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
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 meg |