Mcintosh MC 7205 Service Manual

Page 1

MC7205

POWER AMPLIFIER

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/ Mc72D5 POWER AMPLiFiER

CONTENTS
Performance Specifications 2 Driver Schematic and PCB .........
Notes ..... 2 Driver Ctr/Sub Schematic and PC
Rear Pane! 3 Capacitor Schematic and PCB ..
Section Locations , 3 Meter/Power Guard/Meter Light
Block Diagram t. .4 Display Light Schematic and PCB ..........
Interconnection Diagram . 5-8 Parts Listm
THX Schematic and PCB .9 Exploded Vlew and Parts List.
Heatsink Schematic and PCB 10-11 Repacking Instructions

Heatsink Ctr/Sub Schematic and PCB ............... l2

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SERVICE MANUAL

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PERFORMANCE SPECIFICATIONS

POWER OUTPUT PER CHANNEL
200 watts into 4 ohm loads or 120 watts into 8
ohm loads minimum sine wave continuous
average power output per channel, all channels
operating.

OUTPUT lOAD IMPEDANCE
8 or 4 ohms

RATED POWER BAND
20Hz to 20,000Hz

DYNAMIC HEADROOM
I .6dB

FREQUENCY RESPONSE
+0, 70.25dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 100,000Hz

TOTAL HARMONIC DISTORTION
0.005% maximum at any power level from 250
milliwatt to rated power per channel from 20Hz
to 20,000Hz, all channels operating.

INTERMODULATION DISTORTION
0.005% maximum if instantaneous peak output
per channel does not exceed twice the rated out
put with all channels operating for any combina-
tion of frequencies from ZOhZ to 20,000hz.

SIGNAL TO NOISE RATIO
113dB below rated output, (A Weighted]

1. The heavy lines on the schematics denote the
primary signal path.

2. Unless otherwise noted, all voltages indicated on
the schematics are measured under the following
conditions:

3. 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 in microfarads (uF).
c.1nductor values are in microheneries (UH)

SENSITIVITY
1 volt (2.0V at level control center delent position)

INPUT IMPEDANCE
10,000 ohms

DAMPING FACTOR (WIDE BAND)
200 @ 8 ohms
100 @ 4 ohms

POWER SUPPLY ENERGY STORAGE
215 Joules

POWER REQUIREMENTS

100 Volts, 50/60Hz at 1080 watts

110 Volts, 50/60Hz at 1080 walls

120 Volts, 50/60Hz at 1080 watts

120 Volts, 50/60Hz at 1080 watts

230 Volts, 50/60Hz at 1080 watts

240 Volts, 50/60H2 at 1080 watts

(Refer to rear panel of the MC7205 for the correct
voltage)

DIMENSIONS
Front Panel: 17-1/2 inches (44.5cm) wide, 7-1/16
inches (17.9cm) high. Depth behind front mount»
ing panel is 2l inches (53.3cm) including clear-
ance for connectors. Panel clearance required in
front of mounting panel is 1-1/8 inches (2.9cm)

WEIGHT
53 pounds (24kg) net, 72 pounds (32kg) in
shipping canon

NOTES

4. On PC board drawings, Square pads indicate:
a. Polarized Capacitors - Positive
b. Diode - Cathode
c. Others A Pin
5. WARNING:
Parts marked with the symbol have critical
characteristics. Use only replacement parts recom»
mended by the manufacturer.