McIntosh MC 2155 Owners Manual

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VARIOUS REGULATORY AGENCIES REQUIRE THAT WE BRING THE FOLLOWING INFORMATION TO YOUR ATTENTION. PLEASE READ IT CAREFULLY. WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. The Mclntosh you have purchased is a Model MC 2155. It has a serial number located on the rear panel of the chassis. Record that serial number here: Serial Number The model, serial number and purchase date are im- portant to you for any future service. Record the pur- chase date here: Purchase date Upon application, Mclntosh Laboratory provides a Three-Year Service Contract. Your Mclntosh authorized Service Agency can expedite repairs when you provide the Service Contract with the instrument for repair. To assist, record your Service Contract number here: Service Contract Number

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Your MC 2155 Stereo Power Amplifier will give you many years of pleasant and satisfactory performance. If you have any questions, please contact: CUSTOMER SERVICE Mclntosh Laboratory Inc. 2 Chambers Street Binghamton, New York 13903-9990 Phone: 607-723-3512 Take Advantage of 3 years of Contract Service... Fill in the Application NOW. Contents SERVICE 1 INSTALLATION 2 HOW TO CONNECT 4 FRONT PANEL INFORMATION 9 REAR PANEL INFORMATION 11 PERFORMANCE LIMITS AND RATINGS 12 PERFORMANCE CHARTS 13 TECHNICAL DESCRIPTION 15 BLOCK DIAGRAM 17 MclNTOSH THREE YEAR SERVICE CONTRACT An application for A THREE YEAR SERVICE CONTRACT is included with this manual. The terms of the contract are: 1. Mclntosh will provide all parts, materials and labor needed to return the measured performance of the instrument to the original performance limits. The SER- VICE CONTRACT does not cover any shipping costs to and from the authoriz- ed service agency or the factory. 2. Any Mclntosh authorized service agency will repair Mclntosh instruments at nor- mal service rates. To receive service under the terms of the SERVICE CON- TRACT, the SERVICE CONTRACT CER- TIFICATE must be presented when the instrument is taken to the service agency. 3. Always have service done by a Mclntosh authorized service agency. If the instrument is modified or damaged as a result of unauthorized repair, the SERVICE CONTRACT will be cancelled. Damage by improper use or mishan- dling is not covered by the SERVICE CONTRACT. 4. The SERVICE CONTRACT is issued to you as the original purchaser. To pro- tect you from misrepresentation, this contract cannot be transferred to a se- cond owner. 5. To receive the SERVICE CONTRACT, your purchase must be made from a Mclntosh franchised dealer. 6. Your completely filled in application for the SERVICE CONTRACT must be post- marked within 30 days of the date of purchase of the instrument. 7. To receive the SERVICE CONTRACT, all information on the application must be filled in. The SERVICE CONTRACT will be issued when the completely filled in application is received by Mclntosh Laboratory Incorporated in Binghamton, New York. 8. Units in operation outside the United States and Canada are not covered by the Mclntosh Factory Service Contract, irrespective of the place of purchase. Nor are units acquired outside the U.S.A. and Canada, the purchasers of which should consult with their dealer to ascertain what, if any, service con- tract or warranty may be available locally. Copyright 1981 © by Mclntosh Laboratory Inc. 1

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another lead from the other terminal of the loudspeaker to the left output terminal marked for the impedance of the speaker on the LEFT OUTPUT terminal strip. The right channel speaker is con- nected in the same manner to the RIGHT OUTPUT terminal strip. When multiple speakers are to be connected to either or both outputs, the combined load im- pedance must be calculated. The load must be con- nected to the appropriate impedance tap. Use this table to aid in selecting the correct impedance match: Load impedance in ohms 0.8 to 1.6 1.6 to 3.2 3.2 to 6.4 6.4 and up Connect for: 1 ohm output 2 ohm output 4 ohm output 8 ohm output If a load impedance is used that is lower than the output impedance tap, then reduced power and pos- sible distortion will result. If a load impedance is us- ed that is higher than the output impedance tap, then neither the signal nor the amplifier will be harmed but the power available is reduced. FOR STEREO CONSTANT VOLTAGE OPERATION: For output voltage of 25 volts Connect for: 4 ohms MONOPHONIC OR SINGLE CHANNEL OPERATION When the MC 2155 is used as a monophonic or single channel power amplifier the two channels are combined to produce output up to 300 watts. The outputs must be connected as described below. For monophonic operation using the MONO BRIDGE mode, output impedances of 2, 4, 8, and 16 ohms are accomodated. Output connections are made by connecting to the output terminals as fisted below. Note that neither output terminal is at ground potential. For monophonic operation using the MONO PARALLEL mode, output impedances of ½, 1,2, and 4 ohms are accomodated. Connect as listed below. The common output terminal is at ground potential. Load Impedance In Ohms ½ 1 2 4 Connect - Speaker Lead To: Either Left or Right Common Terminal Either Left or Right Common Terminal Either Left or Right Common Terminal Either Left or Right Common Terminal Connect + Speaker Lead To: Both Left and Right 1 Ohm Terminals Both Left and Right 2 Ohm Terminals Both Left and Right 4 Ohm Terminals Both Left and Right 8 Ohm Terminals FOR MONOPHONIC CONSTANT VOLTAGE LINE OPERATION For output voltage of 25 volts Connected for: 2 ohm output (mono) Be certain that the MC 2155 is never operated in the stereo mode with the outputs connected for monophonic operation. Should the MODE SWITCH be left in the STEREO position and the outputs re- main strapped for a mono parallel load, one channel will attempt to drive the other which causes high cir- culating currents and overheating. AC POWER The MC 2155 operates on 120 volts 50/60 Hz. The auxiliary AC OUTLET on the MC 2155 is not fused or switched. Load Impedance In Ohms 2 4 8 16 Connect - Speaker Lead To: Left 1 Ohm Terminal Left 2 Ohm Terminal Left 4 Ohm Terminal Left 8 Ohm Terminal Connect + Speaker Lead To: Right 1 Ohm Terminal Right 2 Ohm Terminal Right 4 Ohm Terminal Right 8 Ohm Terminal 5