McIntosh MC 2500 Service Manual

Page 1

MC 2500

STEREO POWER AMPLIFIER

This service manual covers MCZSDO units with
serial numbers from C52718 and above. Units
with serial numbers from 051001 to (252717

are covered by schematics 039396 and 039397.

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CONTENTS
Performance Specifications ................................ 2
Mechanical Views ....................................... 3-4
Notes ................................................... 4
Section Locations ........................................ 5
Block Diagram .......................................... 6-7
Front Panel and Trim Parts List ............................ 8
Installation Parts List ..................................... 8
Section 1-Interconnection Diagram ..................... 8-11
Section 2A-Amplifier (serial no. 082718 to 083999) ....... 12-15
Section ZB-Amplifier (serial no. 084000 and above) ...... 16-19
Section 3-Meter Drive and Illumination ............. ,' . .. 20-22
Section 4-Power Supply and Power Guard Display ....... 23-24
Repacking Instructions ................................... 25

mtIUIUSII Service Manual

Page 2

Performance
Specifications

POWER OUTPUT

STEREO: 500 watts minimum sine wave
continuous average power output per
channel, both channels operating into 1
ohm, 2 ohms, 1: ohms, or 8 ohms load
impedance, which is:

22.11 volts RMS across 1 ohm
31.6 volts RMS across 2 ohms
44.7 volts RMS across 4 ohms
63.2 volts RMS across 8 ohms

MONO: 1000 watts minimum sine wave
continuous average power output into 0.5
ohm, 1 ohm, 2 ohms, 4 ohms, 8 ohms, or
16 ohms load impedance, which is:

22.11 volts RMS across 0.5 ohm

31.6 volts RMS across 1 ohm

144.7 volts RMS across 2 ohms

63.2 volts RMS across 4 ohms

89.4 volts RMS across 8 ohms
126.5 volts RMS across 16 ohms

OUTPUT LOAD IMPEDANCE

STEREO: 1 ohm, 2 ohms, A ohms, and 8
ohms; separate terminals are provided for
each output.

MONO-PARALLEL: 0.5 ohms, 1 ohm, 2
ohms, and A ohms; obtained by connecting
in parallel the appropriate terminals of
both channels.

MONO-BRIDGED: 2 ohms, 4 ohms, 8 ohms
or 16 ohms; obtained by connecting to the
output terminals of both channels. The
bridged output is balanced to ground.
Neither side is grounded.

RATED POWER BAND
20Hz to 20,000HZ

TOTAL HARMONIC DISTORTION

STEREO: 0.02% maximum harmonic
distortion at any power level from 250
milliwatts to 500 watts per channel from
20Hz to 20,000Hz, both channels operating.

MONO: 0.02% maximum harmonic
distortion at any power level from 250
milliwatts to 1000 watts from 20Hz to
20,000Hz.

INTERMODULATION DISTORTION

STEREO: 0.02% maximum if instantaneous
peak power output is 1000 watts or less
per channel with both channels operating
for any combination of frequencies, ZOHZ to
20,000Hz.

MONO: 0.02% maximum if instantaneous
peak power output is 2000 watts or less
for any combination of frequencies, 20Hz to
20,000Hz.

FREQUENCY RESPONSE (at one watt output)
ZOHZ to 20,000HZ +0, -0.25dB.
10HZ to 100,00HZ +0.25, -1dB.

NOISE AND HUM
95dB below rated output.

DAMPING FACTOR
Greater than 30

INPUT IMPEDANCE
50,000 ohms

INPUT SENSITIVITY

Switchable: 0.75 or 2.5 volts.
Level control provided for higher input
voltages.

POWER GUARD
THD not to exceed 2% with up to ZOdB
overdrive at 1kHz.

POWER REQUIREMENTS
120 volts, 50/60Hz, 0.7 to 22 amps (15
amps UL/CSA)

WEIGHT
129 pounds (58.5 kg) net, 144 pounds
(65.3 kg) in shipping carton.