McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York MC275 Tube Power Amplifier Owner’s Manual 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.
IMPORTANT! INSTRUCTIONS FOR REMOVAL OF FOAM INSERT OVER THE VACUUM TUBES PRIOR TO CONNECTING THE A.C. POWER SUPPLY CORD, START ON THE NEXT PAGE.
Unpacking the MC275 Caution: To prevent damage to the MC275 Tubes during shipping, there is a special foam insert surrounding the Tubes of the Power Amplifier. The Foam Insert must be removed from the MC275 before connecting the AC Power Supply Cord to the power amplifier. Failure to do so has the potential of a Fire Hazard, resulting in damage to the MC275 and the surrounding environment. Follow these instructions for removal of the packing foam before connecting the AC Power Supply Cord to the MC275.
Unpacking the MC275 and Ventilation Figure 3 Foam Insert Figure 6 Figure 8 Ventilation Adequate ventilation extends the trouble free life of the MC275. Always allow air to flow through the ventilation holes on the bottom of the amplifier and a means for the warm air to escape at the top. Refer to figure 9. Allow at least 19 inches (48.3cm) above the top; 4 inches (10.2cm) for the Rear and Sides; allow 1/2 inch (1.3cm) below the Power Amplifier so the airflow is not obstucted.
Thank You Customer Service General Information Your decision to own this McIntosh MC275 Tube 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.
General Information, Cable Information, Introduction and Performance Features Connector and Cable Information XLR Connectors Below is the Pin configuration for the XLR Balanced Input, Input/Output Connectors on the MC275. Refer to the diagram for connection: INPUT IN/OUT PIN 1: Shield/Ground PIN 2: + Output PIN 3: - Output PIN 2 PIN 1 PIN 3 PIN 1 PIN 3 PIN 2 Power Control Connector The MC275 Power Control Input receives an On/Off signal from +5 to +12 volts.
Dimensions Dimensions The following dimensions can assist in determining the best location for your MC275. Left Side View of the MC275 Front View of the MC275 16-1/2" 41.9cm 1-3/4" 4.5cm 7-7/8" 20.0cm 8-1/2" 21.6cm 1-1/4" 3.2cm Top View of the MC275 1-3/4" 4.5cm Right Side View of the MC275 13-5/8" 34.6cm 5-9/16" 14.1cm 4-3/8" 11.1cm 12" 30.
Left Side Connections, Indicator and Switch; Right Side Connection, Fuse Holder and Switch LEFT OUTPUT Connections for a 4, 8 or 16 ohm Loudspeaker BALanced INPUTS for audio cables from a Preamplifier or A/V Control Center audio output RIGHT OUTPUT Connections for a 4, 8 or 16 ohm Loudspeaker UNBALancded INPUTS for audio cables from a Preamplifier or A/V Control Center audio output Connect the MC275 power cord to a live AC outlet.
How to Connect for Stereo Operation Output Terminals When connecting the Loudspeaker Hookup Cables to the MC275 Power Amplifier Output Terminals please follow the steps below: 1. Rotate the top of the Output Terminal Post counterclockwise until an opening appears. Refer to figures A and B. 2. Insert the Loudspeaker hookup cable into the Output Terminal Opening Post opening or the cable spade Figure B Figure A lug around the center post of the Output Terminal. Refer to figure C. 3.
How to Connect for Stereo Operation (ohms) connection to match the impedance of the Loudspeaker, being careful to observe the correct polarities. If the Loudspeaker’s impedance is in-between the available connections, use the nearest lower impedance connection. Refer to “General Information” Note 3 on page 6 for additional information. WARNING: Loudspeaker Terminals are hazardous live and present a risk of electric shock.
How to Connect for Monaural Operation Output Terminals When connecting the Loudspeaker Hookup Cables to the MC275 Power Amplifier Output Terminals please follow the steps below: 1. Rotate the top of the Output Terminal Post counterclockwise until an opening appears. Refer to figures A and B. 2. Insert the Loudspeaker hookup cable into the Output Terminal Opening Post opening or the cable spade Figure B Figure A lug around the center post of the Output Terminal. Refer to figure C. 3.
How to Connect for Monaural Operation Banana Plugs are for use in the United States and Canada only: 6. Attach the previously prepared bare wire cable ends into the banana plugs and secure the connections. Refer to figure F. 7. For the MC275 MONO Mode of operation, use the supplied Jumper Bars to connect the Output of the Figure F Left and Right Amplifier Channels in parallel.
Right Side Switch, Left Side Switches and Indicators AUTO OFF Switches the Power Save On (ENABLED)or Off (DISABLED) INPUT Switch selects between STEREO and MONO Modes of operation Small Signal Vacuum Tube Handcrafted in USA with US and Imported Parts LED Illumination Color: Amber - Warmup Mode Green - Normal Operation Red - Sentry Monitor INPUT Switch selects between balanced or unbalanced input POWER Switch Turns AC Power ON, or OFF/ REMOTE Standby Power On Indicator 14
How to Operate How to Operate Power With the POWER Switch (located on the Left Side of the MC275) set to the OFF/REMOTE Position, the MC275 will turn On or Off when the PreamHandcrafted in USA with US plifier turns On or Off. For manand Imported PartsFigure 10 ual operation, place the POWER Switch to the ON Position as desired. Refer to figure 10. The LED indicator located above the Power Switch is illuminated when Figure 11 the MC275 to connected to an active AC Outlet. Refer to figure 11. Notes: 1.
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Specifications Specifications Power Output Stereo Minimum sine wave continuous average power output per channel, both channels operating is: 75 watts into 4 ohm loads 75 watts into 8 ohm loads 75 watts into 16 ohm loads Power Output Mono (Parallel) Minimum sine wave continuous average power output is: 150 watts into 2 ohm load 150 watts into 4 ohm load 150 watts into 8 ohm load Output Load Impedance 4, 8 or 16 ohms (Stereo Mode) 2, 4 or 8 ohms (Mono Mode) Rated Power Band 20Hz to 20,000Hz Total Harmonic Dis
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. To protect the tubes during shippment, the Foam Insert removed from the MC275 needs to be re-inserted.
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.
