Page 3 - ThermalTrakTM and ON Semiconductor are trademarks of Semi-
3 Cable Information, Introduction and Performance Features Connector and Cable Information Introduction Now you can take advantage of traditional McIntosh standards of excellence in the MC312 Power Amplifi- er. The 300 watts power per channel with high current output will drive any pair of high qual...
Page 4 - The following dimensions can assist in determining; Dimensions; Front View of the MC312
4 Dimensions The following dimensions can assist in determining the best location 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"...
Page 5 - Be sure to cut out a; When the MC312 is installed together with other McIn-; Custom Cabinet Cutout; in Custom Cabinet
5 Installation Installation The MC312 can be placed upright on a table or shelf, standing on its four feet. It also can be custom installed in a piece of furniture or cabinet of your choice. The four feet may be removed from the bottom of the MC312 when it is custom installed as outlined below. The ...
Page 6 - Rear Panel Connections and Switch
6 DISABLED Connect the MC312 power cord to a live AC outlet. Refer to the rear panel to determine the correct voltage RIGHT OUTPUT Connections for a 2 ohm, 4 ohm or 8 ohm Loudspeaker Rear Panel Connections and Switch Fuse holder, refer to information on the rear panel of your MC312 to determine the ...
Page 7 - Banana Plugs are for use in the United States and; Post clockwise until it is finger tight.; How to Connect; Loudspeaker Cable Distance vs Wire Gauge Guide; Caution: Do not connect the AC Power Cord to the; appears. Refer to figures A and; Output Terminals; Output Terminals and How to Connect
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. I...
Page 8 - Spade Lug or Wire Connections:; Output Terminals and How to Connect, con’t; Figure 7
8 Note: The illustration on separate sheet “ Mc1A ”is connections for 8Ω (ohms) Loudspeakers. If the 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: Lou...
Page 9 - How to Connect for Bi-Amp; Figure A; Figure B; Output Terminals and How to Connect for Bi-Amp
9 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 12AW...
Page 10 - Note: The illustration on separate sheet “; Figure G
10 impedance of the Loudspeaker, being careful to observe the correct polarities. Insert the spade lug connector or prepared section of the cable end into the terminal side access hole, and tighten the terminal cap until the cable is firmly clamped into the terminals so the lugs or wire cannot slip ...
Page 12 - Front Panel Displays and Controls
12 Front Panel Displays and Controls Standby Power On Indicator POWER Switch Turns AC Power Off, Remote, AC Power On METER Switch selects 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 A...
Page 13 - How to Operate; Figure 9
13 Input Mode Switch The Input Mode Switch, which is located on the Rear Panel of the MC312, allows selection of either the Balanced or Unbalanced Input. Refer to figure 12. Auto Off Switch The MC312 incorporates Power Save Circuitry to automatically place the MC312 into the power saving Standby Mod...
Page 14 - Design Philosophy; Technical Description
14 McIntosh Laboratory, the company who introduced the world’s first amplifier that could be called “High Fidelity”, has done it again. The McIntosh engineering staff has created a power amplifier without compro- mise, using the most advanced McIntosh circuit design concepts. The MC312 has a continu...
Page 15 - Autoformers; Block Diagram of the Power Amplifier
15 All transistors are selected to have nearly constant current gain over the entire current range they must cover. Output transistors in particular, have matched uniform current gain, high current bandwidth prod- uct and large active region safe operating area. These Power Transistors are the very ...
Page 16 - Input Test Signal; Technical Description, con’t
16 Refer to figure 18. There is abso- lutely no perfor- mance limitation with an Autoformer. Its frequency re- sponse exceeds that of the output circuit itself, and extends well beyond the audible range. Its distortion level is so low it is virtu- ally impossible to measure. In the rare event of a p...
Page 17 - Power Supply Circuits; Block Diagram
17 perfectly preserved. The MC312 Power Amplifier with Power Guard is not limited to just the rated power output, but will actually produce distor- tion free output well above its rated power due to the McIntosh phi- losophy of conservative design. Power Supply Circuits To compliment the design of t...
Page 18 - Field AC Voltage conversion of the MC312 is not; Note: Refer to the rear panel of the MC312 for the cor-
18 Specifications Specifications Power Output Minimum sine wave continuous average power output per channel, with both channels operating is: 300 watts into 2 ohm load 300 watts into 4 ohm load 300 watts into 8 ohm load Output Load Impedance 2, 4 or 8 ohms Rated Power Band 20Hz to 20,000Hz Total Har...
