INSTRUCTION MANUAL

McINTOSH MODEL MC-30

30 WATT POWER AMPLIFIER

Type A-116B Serial #9E341 and above

038-243

MCINTOSH LABORATORY, INC

DESCRIPTION

The McIntosh Model MC-30 is a 30 watt high fidelity power amplifier designed for home entertainment s y s t e m s and p r o f e s s i o n a l applications. The Model MC-30 is similar to the earlier McIntosh Model A-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 combination of frequencies 20 to 20, 000 cps; and noise and hum level 90 db or more below rated o u t p u t. The famous McIntosh high efficiency output circuit is used to obtain the high standard of performance found in this amplifier.
The MC-30 maybe operated from any signal source d e l i v e r i n g 0. 5 or more volts, or d i r e c t l y 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 loudspeakers. 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 c i r c u l a t i o n.

Input Connections

1. When a McIntosh Audio Compensator or other McIntosh p r e - a m p l i f i e r is used with the MC-30, plug the pre-amplifier's output-power cord into the " P r e - A m p input" receptacle on the MC-30 and turn the "gain" control fully counter clockwise. This receptacle supplies the required plate and filament power to the p r e - a m p l i f i e r e q u i p m e n t as well as providing the necessary audio connection.
For pre-amplifier installation and operation refer to the p r e - a m p l i f i e r ' s i n s t r u c t i o n 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.

GUARANTEE

We guarantee the performance of this equipment and the mechanical and electrical workmanshipto 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 f r o m the f a c t o r y.
SERVICE I N F O R M A T I O N
All McIntosh equipment is designed far long trouble f r e e o p e r a t i o n. All c o m p o n e n t s are of highest quality and are conservatively operated. If t r o u b l e develops the a m p l i f i e r m a y be s e r viced by your franchised dealer, a competent s e r v i c e m a n , or r e t u r n e d to the f a c t o r y. E q u i p ment will not be accepted at the f a c t o r y unless f a c t o r y r e t u r n a u t h o r i z a t i o n is f i r s t r e c e i v e d. The following chart of operating v o l t a g e s and r e s i s t a n c e s is o f f e r e d as a g u i d e for s e r v i c i n g the unit. All voltages and r e s i s t e n c e s a r e m e a s u r e d to c h a s s i s e x c e p t those w i t h a s t e r i s k (*). These are m e a s u r e d to chassis with pin #2 of the 5U4GB g r o u n d e d. V o l t a g e s are m e a s u r e d with high impedence V T V M. N O T E - - U N I T MUST BE T U R N E D OFF WHEN MEASURING RESISTENCES. VOLTAGE A N D RESISTANCE CHART DC Volts No Signal DC Volts at 30W out AC Volts at 30W out Resistance U n i t off 330K* 1M 3.3K 0 to to 70

Tube 12AX7 (Input)

Pin No. 3 4&5 6, 7, 3&8 4&3&8 4&7 9
1.2 Fil Fil 138 Fil Fil 16 Fil Fil
1. 1 6. 3 V. ac to Pin 6. 3 V. ac to Pin 6. 3 V. ac to Pin 0 -
1. 3 0. 24 0. 13 0. 9 0. 9 -
40* 330K* 13K 0 to 70 43K* 26M* 0 to 70
12K* 220K 1.2K 0 to 70 12K* 220K 0 to 70
ELECTRICAL AND MECHANICAL SPECIFICATIONS Specifications for the McIntosh Model MC-30 Audio Amplifier
Power Supply Power C o n s u m p t i o n
117/125 volta, 50/60 cycles 135 watts at 30 watts output 105 watts at zero signal output 30 watts continuous Input #1 (pin jack and screw terminals and pin 5 of pre-ampsocket).5 volts to 30 volts, with gain control Input #2 (pin 2 of pre-amp socket) 2. 5 volts, (For use with McIntosh pre-amplifier equipment) 20 to 30, 000 cycles .1 db at 30 watts output 15 to 50,000 cycles .5 db at 30 watts output 10 to 100.000 cycles 1 db at 15 watts output Less than 1/3% at 30 watts output or less, 20 to 20, 000 cycles Less than 1/2% if instantaneous peak power is below 60 watts for any combination of frequencies 20 to 20, 000 cycles Negligible 90 db or more below rated output 12 or better for 4, 8 and 16 ohm output, 16 for 600 ohms 0. 5 meg for 0. 5 volt input and 0. 13 meg for 2. 5 volt input. 20 cycles to 40 Kc 4, 8, 16. 166 (70. 7 volts) and 600 ohms (600 ohm is balanced to ground) 20 cycles 3 20, 000 cycles 9 Pre-Amp: 12AX7 Phase Inverter: 12AU7 Voltage Amp: 12 BH7 Driver: 12AX7 Output: 2--6L6 GC/1614 Rectifier: 5U4-GA Designed to power C-8 and other McIntosh Pre-Amplifiers 13" x 8" x 8" high, chassis type construction 30. 5 pound, net Chrome and Black

Power Output Input level

Frequency Range

Harmonic

Distortion
Intermodulation Distortion
Impulse Distortion N o i s e and Hum Level Damping Factor
Input Impedance Output Impedance Phase Shift Tube Complement
Auxiliary Equipment connection ("Pre-Amp input" receptacle)

Size Weight Finish