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7

3. Prepare the Loudspeaker Hookup Cable for attach-

ment to the MC312 Power Amplifier:

Bare wire cable ends:

Carefully remove sufficient insulation from the 

cable ends, refer to figures 2, 3 & 4. If the cable 

is stranded, carefully twist the strands together 

as tightly as possible.

Notes: 1. If desired, the twisted ends can be tinned 

with solder to keep the strands together.

2. The prepared bare wire cable ends may be 

inserted into spade lug connectors.

3. Banana plugs are for use in the United 

States and Canada only.

Banana Plugs are for use in the United States and 

Canada only:

4. Attach the previously prepared bare wire cable ends 

into the banana plugs and secure the 

connections. Refer to figure F.

5. Rotate the top of the Output Terminal 

Post clockwise until it is finger tight. 

Refer to figure G. Then using the Mc

-

Intosh Wrench, rotate the top of the 

Output Terminal one quarter of a turn 

(90° ). 

Do not over tighten.

 Refer to 

figure E.

6. Referring to figure H, connect the 

Loudspeaker hookup 

cables with banana plugs 

into the hole at the top 

of the terminal to the 

How to Connect

1. For Remote Power Control, connect a power control 

cable from the Audio Preamplifier or A/V Con-

trol Center Power Control Output 1 to the MC312 

POWER CONTROL IN.

Notes: 1. When a Power Control Cable is connected 

between the MC312 and Preamplifier (or 

A/V Control Center), the AUTO OFF Fea-

ture is bypassed. Refer to page 13.

2. When the MC312 has Loudspeakers con-

nected to it with a Power Control Input, 

connect the MC312 Power Control Out 1 

and Out 2 to the Loudspeakers.

2. Connect XLR cables from the Balanced Output 1 

(L&R) of an Audio Preamplifier or A/V Control 

Center to the MC312 Balanced INput (RIGHT and 

LEFT). Place the INPUT MODE Switch in the 

BALANCED Position.

Note: An optional hookup is to use unbalanced 

cables and place the INPUT MODE Switch in 

the UNBALANCED Position.

This McIntosh MC312 Power Amplifier is designed 

for Loudspeakers with an impedance of 2 ohms, 4 

ohms or 8 ohms. Connect a single Loudspeaker only 

to the Right and Left Output Terminals.

When connecting Loudspeakers to the MC312 it 

is very important to use cables of adequate size, so 

there is little to no power loss in the cables. The size is 

specified in Gauge Numbers or AWG (American Wire 

Gauge). The smaller the Gauge number, the larger the 

wire size:

Loudspeaker Cable Distance vs Wire Gauge Guide

Loudspeaker

Impedance

25 feet

(7.62 meters)

or less

50 feet

(15.24 meters)

or less

100 feet

(30.48 meters)

or less

2 Ohms

12AWG

10AWG

8AWG

4 Ohms

14AWG

12AWG

10AWG

8 Ohms

16AWG

14AWG

12AWG

Caution: Do not connect the AC Power Cord to the 

MC312 Rear Panel until after the Loudspeaker 

Connections are made. Failure to observe this 

could result in Electric Shock.

The connection instructions below, together with the 

MC312 Connection Diagram located on the separate 

folded sheet “

Mc1A

”, is an example of a typical audio 

system. Your system may vary from this, however the 

actual components would be connected in a similar 

manner. For additional information refer to “Connec-

tor and Cable Information” on page 3.

Figure 2

Figure 3

Figure 4

When connecting the Loudspeaker Hookup Cables to 

the MC312 Power Amplifier Output Terminals please 

follow the steps below:

1. Rotate the top of the Output Terminal Post coun-

terclockwise until an opening 

appears. Refer to figures A and 

B.

2. Insert the Loudspeaker hookup 

cable into the Output Terminal 

Post opening or the cable spade 

lug around the center post of 

the Output Terminal. Refer to 

figure C.

3. Rotate the top of the Output 

Terminal Post clockwise until it 

is finger tight. Refer to figure D.

4. Place the supplied McIntosh 

Wrench over the top of the Out-

put Terminal and rotate it one 

quarter of a turn (90° ) to secure 

the Loudspeaker Cable Connec-

tion. 

Do not over tighten.

 Refer 

to figure E.

Output Terminals

Figure A

Opening

Figure B

Figure C

Figure D

Figure E

Figure F

Figure H

Figure F

Figure H

Figure G

Output Terminals and How to Connect

Summary of Contents for MC312

Page 1: ...McIntosh Laboratory Inc 2 Chambers Street Binghamton New York 13903 2699 Phone 607 723 3512 www mcintoshlabs com MC312 Power Amplifier Owner s Manual...

Page 2: ...rtant Additional Operation Information Guide Thank You and Please Take a Moment 2 Technical Assistance and Customer Service 2 Table of Contents 2 General Information 2 Connector and Cable Information...

Page 3: ...n though the power line varies Illuminated Power Meters The Illuminated Power Output Watt Meters on the MC312 are peak responding and indicate the true power output of the amplifier The Peak Watt Hold...

Page 4: ...for your MC312 Dimensions Front View of the MC312 Rear View of the MC312 Side View of the MC312 17 1 2 44 5cm 8 7 8 22 5cm 9 7 16 24 0cm 11 3 4 29 9cm 16 13 16 43 0cm DISABLED 20 50 8cm 3 16 0 5cm 16...

Page 5: ...ble oper ating temperature A custom cabinet installation should provide the fol lowing minimum spacing dimensions for cool opera tion Allow at least 6 inches 15 24cm above the top 2 inches 5 08cm belo...

Page 6: ...n tosh Component Unbalanced INput RIGHT Channel for an audio cable from a Preamplifier or A V Con trol Center audio output Unbalanced OUTput RIGHT Channel for an audio cable to the next Power Amplifie...

Page 7: ...McIntosh MC312 Power Amplifier is designed for Loudspeakers with an impedance of 2 ohms 4 ohms or 8 ohms Connect a single Loudspeaker only to the Right and Left Output Terminals When connecting Loudsp...

Page 8: ...Loudspeaker s impedance is in between the available connections use the nearest lower impedance connection Refer to General Informa tion Note 3 on page 2 for additional information WARNING Loudspeake...

Page 9: ...ptional hookup is to use unbalanced cables and place the INPUT MODE Switch in the UNBALANCED Position 4 Connect XLR cables from the MC312 Power Amplifier 1 Audio Balanced OUTput LEFT and RIGHT to the...

Page 10: ...uarter of a turn 90 Do not over tighten Refer to figure E on page 9 8 Referring to figure H connect the Loudspeaker hookup cables with ba nana plugs into the hole at the top of the terminal to the MC3...

Page 11: ...11...

Page 12: ...the display modes of the Power Output Meter and Meter Illumination Meter indicates the Right Channel Output of the amplifier LED indicates when the LEFT Channel Amplifier POWER GUARD circuit activate...

Page 13: ...MC312 and the Audio Preamplifier or A V Con trol Center in order for the remote power turn on to function Meter Selection Rotate the meter mode switch to select the meter operation mode you desire Re...

Page 14: ...can deliver the best possible performance from any type of high quality loudspeaker system Refer to figure 14 Creating an amplifier with this level of perfor mance did not come easily Many months of...

Page 15: ...at is lower than optimum causes more output current to flow which results in extra heat being generated in the power output stage This increase in temperature will result in a reduced life expectancy...

Page 16: ...se in sonic perfor mance with this circuit and it ensures safe operation of the amplifier under even the most extreme operat ing conditions The different types of protection circuits incorporated in t...

Page 17: ...ntrol Out Jacks The Power Control signal from these jacks is delayed by a fraction of a second so that the turn on power surge of the next power amplifier occurs at a later time This helps prevent pow...

Page 18: ...tor Greater than 40 Input Impedance 22 000 ohms Balanced 22 000 ohms Unbalanced Voltage Gain 29dB 8 Ohms 26dB 4 Ohms 23dB 2 Ohms Power Guard Less than 2 Total Harmonic Distortion with up to a 14dB ove...

Page 19: ...shipping damage Use the original shipping carton and interior parts only if they are all in good serviceable condition If a shipping carton or any of the interior part s are needed please call or writ...

Page 20: ...cts is the policy of McIntosh Laboratory Incorporated who reserve the right to improve design without notice Printed in the U S A McIntosh Laboratory Inc 2 Chambers Street Binghamton NY 13903 www mcin...

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