McIntosh MA7000, Service Manual

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1. Unless otherwise noted, all voltages indicated on the
schematics are measured under the following conditions:
a. AC input at rated voltage marked on rear panel.
b. All voltages are +/-10% with respect to ground. A
high impedance (10 megaohm) voltmeter must be used.
2. Unless otherwise specified:
a. Resistor values are in ohms.
b. Capacitor values are microfarads (uF).
c. Inductor values are in microhenries (uH)
3. On PC board drawings, Square pad indicates:
a. Polarized Capacitors - Positive
b. Diodes - Cathode
c. Others - Pin 1
4.
WARNING
Parts marked with the symbol have critical
characteristics. Use only replacement parts recom-
mended by the manufacturer.
5. Use McIntosh Remote Control Model HR063.
NOTES
PERFORMANCE SPECIFICATIONS
Specifications
Power Output
250 watts is the minimum sine wave continuous average
power output per channel, both channels operating
Output Load Impedance
2, 4 or 8 ohms
Rated Power Band
20Hz to 20,000Hz
Total Harmonic Distortion
0.005% maximum with both channels operating from 250 mil-
liwatts to rated power, 20Hz to 20,000Hz
Dynamic Headroom
2.0dB
Frequency Response
+0, -0.5dB from 20Hz to 20,000Hz
+0, -3dB from 10Hz to 100,000Hz
Preamplifier Main Output (for rated input)
2.5V unbalanced (8V Maximun)
5.0V balanced (16V Maximun)
Sensitivity (for rated output)
High Level, 250mV unbalanced, 500mV balanced
Phono, 1.2 mV
Power Amp In, 2.5V
Signal To Noise Ratio (A-Weighted)
High Level, 100dB below rated output
Phono, 84dB below 5mV input
Power Amplifier, 115 below rated output
Intermodulation Distortion
0.005% maximum, if the instantaneous peak power is 500
watts or less per channel with both channels operating for any
combination of frequencies from 20Hz to 20,000Hz
Wide Band Damping Factor
Greater than 40
Input Impedance
High Level, 20K ohms
Phono, 47K ohms; 65pF
Power Amp In, 10K ohms
Maximum Input Signal
High Level, 8V unbalanced, 16V balanced
Phono, 45mV
Power Amplifier In, 16V
Main Output Impedance
50 ohms
Power Guard
Less than 2% THD with up to 16dB overdrive at 1,000Hz
Voltage Gain
High Level to Rec Output: 0dB
High Level to Main Output: 20dB
Phono to Rec Output: 46dB
Phono to Main Output: 66dB
Power Amplifier: 25dB
Equalizer Controls
Variable 12dB boost to 12dB cut at 30Hz, 150Hz, 500Hz,
1500Hz and 10,000Hz
Power Requirements
100 Volts, 50/60Hz at 8.0 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
Standby: Less than 1 watt
Note: Refer to the rear panel of the MA7000 for the
correct voltage.
Overall Dimensions
Width is 17-1/2 inches (44.45cm)
Height is 9-7/16 inches (23.97cm) including feet
Depth is 22 inches (55.88cm) including the Front Panel,
Knobs and Cables
Weight
97.5 pounds (44.3 kg) net, 130.5 pounds (59.2 kg) in ship-
ping carton
Shipping Carton Dimensions
Width is 29-1/2 inches (74.93cm)
Depth is 29 inches (73.66cm)
Height is 17 inches (43.18cm)