Power Amplifier MC303 Owner’s Manual McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York 13903-2699 Phone: 607-723-3512 www.mcintoshlabs.
The lightning flash with arrowhead, within an equilateral triangle, is intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons. WARNING - TO REDUCE RISK OF FIRE OR ELECTRICAL SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. IMPORTANT SAFETY INSTRUCTIONS! PLEASE READ THEM BEFORE OPERATING THIS EQUIPMENT. 1. Read these instructions. 2. Keep these instructions. 3.
Thank You Table of Contents Your decision to own this McIntosh MC303 Power Amplifier ranks you at the very top among discriminating music listeners. You now have “The Best.” The McIntosh dedication to “Quality,” is assurance that you will receive many years of musical enjoyment from this unit. Please take a short time to read the information in this manual. We want you to be as familiar as possible with all the features and functions of your new McIntosh. Safety Instructions..............................
Connector Information, Introduction and Performance Features General Information, con’t 6. When discarding the unit, comply with local rules or regulations. Batteries should never be thrown away or incinerated but disposed of in accordance with the local regulations concerning battery disposal. 7. For additional information on the MC303 and other McIntosh Products please vist the McIntosh Web Site at www.mcintoshlabs.com. 8.
Dimensions Dimensions The following dimensions can assist in determining the best location for your MC303. There is additional information on the next page pertaining to installing the MC303 into cabinets. 17-3/4" 45.09cm 10-7/8" Front View of the MC303 27.62cm 12-3/8" 31.43cm 17-3/8" 44.15cm Rear View of the MC303 F15AH 125V 12-1/4" 31.11cm 19-1/2" 49.50cm 18" 1-5/8" 45.72cm 4.12cm Side View of the MC303 3/16" 0.48cm 1-1/2" 3.81cm 14" 35.60cm 10-1/2" 26.70cm 1-9/16" 3.
Installation Installation sure to cut out a ventilation hole in the mounting shelf acThe MC303 can be placed upright on a table or shelf, cording to the dimensions in the drawing. standing on its four feet. It also can be custom installed in a piece of furniture or cabinet of your choice. The four feet 1 When the MC303 is installed together with other McIntosh may be removed from the bottom of the MC303 when it is Components, check clearances on all components before custom installed as outlined below.
Rear Panel Connections and Switch UNBALANCED INPUT 3 for an audio cable from an A/V Control Center or Preamplifier audio output POWER CONTROL IN receives turn On/Off signal from a McIntosh component and the POWER CONTROL OUT sends a turn On/Off signal to the next McIntosh Component BALANCED INPUT 3 for an audio cable from an A/V Control Center or Preamplifier audio output BALANCED INPUT 2 for an audio cable from an A/V Control Center or Preamplifier audio output UNBALANCED INPUT 2 for an audio cable fro
How to Connect for Center and Surround Channels Caution: The supplied AC Power Cord should not be connected to the Rear Panel of the MC303 Amplifier until after the Loudspeaker Connections have been made. Failure to observe this could result in Electric Shock. For additional instruction on making Loudspeaker Connections contact your McIntosh Dealer or McIntosh Technical Support.
How to Connect How to Connect for Left, Center and Right Channels Caution: The supplied AC Power Cord should not be connected to the Rear Panel of the MC303 Amplifier until after the Loudspeaker Connections have been made. Failure to observe this could result in Electric Shock. For additional instruction on making Loudspeaker Connections contact your McIntosh Dealer or McIntosh Technical Support.
Front Panel Displays and Switches Meters indicate the Amplifier Power Output of Channels 1-3 LEDs indicate when Amplifier Channels 1-3 POWER GUARD circuits activate Standby Power On Indicator METER Switch selects Meter Illumination Auto (On) or Off 10 POWER Switch Turns AC Power On/Off, or On/Remote
How to Operate How to Operate Power On To have the MC303 automatically turn On or Off when an A/V Control Center or Preamplifier turns on or off, rotate the power switch to the REMOTE position. For manual operation, rotate the power switch to the ON or OFF position as desired. Refer to figure 8. Note: There must be a power control connection between the MC303 and the A/V Control Center or Preamplifier, in order for the remote power turn-on to function.
Technical Description 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 compromise, using the most advanced McIntosh circuit design concepts.
Technical Description POSITIVE SENTRY MONITOR Power Amplifier Block Diagram THERMAL TRAK DC BIAS com (one channel shown) NEGATIVE SENTRY MONITOR BALANCED AMP Figure 12 Design Philosophy The design philosophy incorporated in the MC303 involved several different techniques, all based on sound scientific logic. Refer to figure 12. Every stage of voltage or current amplification must be as linear as possible prior to the use of negative feedback.
increase in temperature will result in a reduced life expectancy for the amplifier. The Autoformer creates an ideal match between the Power Amplifier Output Circuitry and the Loudspeaker. There is absolutely no performance limitation with an Autoformer. Its frequency response from below 20Hz to well beyond 20,000Hz exceeds the Power Output Circuitry Frequency Response, and extends well beyond the audible range. Its distortion level is so low it is virtually impossible to measure.
Technical Description, con’t Power Supply Block Diagram STANDBY TRANSFORMER STANDBY SUPPLY Figure 20 can store over 200 Joules of energy, for the three amplifier channels, necessary for the wide dynamic range “Digital Audio” demands. Refer to figure 22. Figure 22 There is also a fully regulated low voltage power supply to guarantee excellent signal to noise ratio. Refer to figure 22. Also, most owners desire one power switch for the whole audio system.
Top View of the MC303 16
Photos Angle View of the MC303 Rear View of the MC303 17
Specifications Specifications Power Output Minimum sine wave continuous average power output per channel, all channels operating: 300 watts into a 2 ohm, 4 ohm or 8 ohm load Output Load Impedance 2, 4 or 8 ohms Rated Power Band 20Hz to 20,000Hz Total Harmonic Distortion 0.005% maximum harmonic distortion at any power level from 250 milliwatts to rated power, 20Hz to 20,000Hz Dynamic Headroom 1.8dB Frequency Response +0, -0.
Packing Instructions Packing Instructions In the event it is necessary to repack the equipment for shipment, the equipment must be packed exactly as shown below. It is very important that the four feet are attached to the bottom of the equipment. This will ensure the proper equipment location on the bottom foam pad. Failure to do this will result in shipping damage. Use the original shipping carton and interior parts only if they are all in good serviceable condition.
McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, NY 13903 www.mcintoshlabs.com The continuous improvement of its products is the policy of McIntosh Laboratory Incorporated who reserve the right to improve design without notice. Printed in the U.S.A. McIntosh Part No.
