McIntosh MA2275

PERFORMANCE SPECIFICATIONS
2
1. The heavy lines 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 recom-
mended by the manufacturer.
NOTES
Power Output
Minimum sine wave continuous average power output per
channel, both channels operating is:
75 watts into a 2 ohm load
75 watts into a 4 ohm load
75 watts into an 8 ohm load
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:
0.5% for a 2, 4 or 8 ohm load
Frequency Response
+0, -0.5dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 50,000Hz
Sensitivity
Phono: 4.4mV for 2.5V preamp output
High Level: 450mV for 2.5V preamp output
Power Amplifier Input: 2.5V for rated output
A-Weighted Signal To Noise Ratio
Phono Input: 80dB below 10mV input
High Level: 97dB below rated output
Power Amplifier: 110dB below rated output
Intermodulation Distortion
Maximum Intermodulation Distortion if instantaneous
peak output does not exceed twice the rated output, for
any combination of frequencies from 20Hz to 20,000Hz is:
0.5% for a 2, 4 or 8 ohm load
Input Impedance
Phono: 47k ohms, 65pF
High Level: 22k ohms
Maximum Input Signal
Phono: 90mV
High Level: 8V
Preamplifier Maximum Voltage Output
Phono: 8V
High Level: 8V
Main Out: 8V at preamp output
Voltage Gain
High Level to Tape output: 0dB
High Level to Preamp output: 15dB
Wide Band Damping Factor
Greater than 18
Power Requirements
100 Volts, 50/60Hz at 3.6 amps
110 Volts, 50/60Hz at 3.6 amps
120 Volts, 50/60Hz at 3.6 amps
220 Volts, 50/60Hz at 1.8 amps
230 Volts, 50/60Hz at 1.8 amps
240 Volts, 50/60Hz at 1.8 amps
Note: Refer to the rear panel of the MA2275 for the correct
voltage.
Preamplifier Tube Compliment
2 - 12AX7A Phono Circuitry
2 - 12AX7A High Level Circuitry
Power Amplifier Tube Compliment
2 - 12AT7
4 - KT88/6550
Overall Dimensions
Width is 17-3/4 inches (45.09cm), Height is 10-1/8 inches
(25.72cm) including feet, Depth is 18-3/4 inches (47.63cm)
including the Front Panel and Knobs
Weight
77 pounds (35 kg) net, 110 pounds (50 kg) in shipping
carton