Page 1
DESCRIPTION
The McIntosh Model MC-30 is a 30 watt high fidelity power amplifier designed for home en-
tertainment systems and professional applications. The Model MC-30 is similar to the earlier
McIntosh Model A-116 30 watt amplifiers and includes all of the rigid electrical specifications
and features found in these earlier units plus: less than 1/3% harmonic distortion at any power
output up to 30 watts and at any frequency in the audio spectrum, 20 to 20,000 cps; less than
1/2% intermodulation distortion if instantaneous peak power is below 60 watts for any combin-
ation of frequencies 20 to 20, 000 cps; and noise and hum level 90 db or more below rated output.
The famous McIntosh high efficiency output circuit is used to obtain the high standard of per-
formance found in this amplifier.
The MC-30 maybe operated from any signal source delivering 0. 5 or more volts, or directly
from a McIntosh Audio Compensator or Pre-Amplifier, such as the Models C-8, C-4, C-104,
or C-108. Output impedances of 4, 8 and 16 ohms are provided for direct connection to loud-
speakers. Additional outputs for 166 ohms (70.7 volts) and 600 ohms are provided for use with
multiple speaker systems, lines, etc.
INSTALLATION
Location
The MC-30 should be located in a ventilated area. If the amplifier is housed in a cabinet or
other enclosure, holes should be provided for air circulation.
Input Connections
1. When a McIntosh Audio Compensator or other McIntosh pre-amplifier is used with the
MC-30, plug the pre-amplifier's output-power cord into the "Pre-Amp input" receptacle on the
MC-30 and turn the "gain" control fully counter clockwise. This receptacle supplies the re-
quired plate and filament power to the pre-amplifier equipment as well as providing the neces-
sary audio connection.
For pre-amplifier installation and operation refer to the pre-amplifier's instruction manual.
2, When a signal source of 0. 5 volts or more is used to drive the amplifier, such as the
output from a tuner, tape recorder, or pre-amplifier, plug the source into the "0. 5 volt input"
pin jack receptacle or connect to the "0.5 volt" and "GND" screw terminals. Use the "gain"
control to obtain the desired operating level.
Page 2
GUARANTEE
We guarantee the performance of this equipment and the mechanical and electrical workman-
shipto be free of defects for a period of 90 days. This guarantee does not extend to components
iamaged by improper use nor does it extend to transportation to and from the factory.
SERVICE INFORMATION
All McIntosh equipment is designed far long trouble free operation. All components are of
highest quality and are conservatively operated. If trouble develops the amplifier may be ser-
viced by your franchised dealer, a competent serviceman, or returned to the factory. Equip-
ment will not be accepted at the factory unless factory return authorization is first received.
The following chart of operating voltages and resistances is offered as a guide for servicing the
unit. All voltages and resistences are measured to chassis except those with asterisk (*).
These are measured to chassis with pin #2 of the 5U4GB grounded. Voltages are measured
with high impedence VTVM. NOTE--UNIT MUST BE TURNED OFF WHEN MEASURING RE-
SISTENCES.
VOLTAGE AND RESISTANCE CHART
Tube
12AX7
(Input)
12AU7
12BH7
Pin No.
1
2
3
4&5
6, 7, 8
9
1
2
3&8
4&5
6
7
9
1
2
3&8
4&5
6
7
9
DC Volts
No Signal
134
0
1.2
Fil
-
Fil
270
134
138
Fil
270
110
Fil
355
0
16
Fil
355
0
Fil
DC Volts
at 30W out
120
0
1. 1
6. 3 V. ac to Pin 9
-
-
235
120
126
6. 3 V. ac to Pin 9
235
100
-
295
0
14
6. 3 V. ac to Pin 9
295
0
-
AC Volts
at 30W out
1. 3
0. 24
0. 22
-
-
-
9
13
0. 57
-
9
0
-
132
9
0. 32
132
9
-
Resistance
Unit off
330K*
1M
3.3K
0 to 70
-
0 to 70
40*
330K*
13K
0 to 70
43K*
26M*
0 to 70
12K*
220K
1.2K
0 to 70
12K*
220K
0 to 70
