THE MclNTOSH MC 2255 SOLID STATE STEREO POWER AMPLIFIER Reading Time: 31 Minutes Price $2.
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 2255. 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 important to you for any future service.
Your MC 2255 Stereo Power Amplifier will give you many years of pleasant and satisfactory performance. If you have any questions, please contact: Contents CUSTOMER SERVICE Mclntosh Laboratory Inc. 2 Chambers Street Binghamton, New York 13903 Phone: 607-723-3512 SERVICE INSTALLATION HOW TO CONNECT FRONT PANEL INFORMATION REAR PANEL INFORMATION PERFORMANCE LIMITS AND RATINGS PERFORMANCE CHARTS TECHNICAL DESCRIPTION BLOCK DIAGRAM Take Advantage of 3 years of Contract Service... Fill in the Application NOW.
How to Connect INPUT STEREO OPERATION duction for which the loudspeakers have been designed. If undersize wire is used, resistance is added to the amplifier/loudspeaker combination which adversely affects the performance. Added resistance causes depreciation of damping characteristics, modification of frequency response and reduction in power output. Use shielded cables to connect the signal from the preamplifier or signal source to the power amplifier.
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 connected in the same manner to the RIGHT OUTPUT terminal strip. 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.
Stereophonic Connections PROGRAM SOURCE LEFT SPEAKER MUST BE IN STEREO POSITION FOR STEREO PROGRAMS 6 RIGHT SPEAKER
Mono-Bridge Connections PROGRAM SOURCE (CONNECTIONS FOR 8 OHM SPEAKER ILLUSTRATED) CONNECTIONS SHOWN FOR MONO WHEN MODE SWITCH IS IN THE MONO-BRIDGE POSITION SPEAKER 7
Mono-Parallel Connections PROGRAM SOURCE (CONNECTIONS FOR 4 OHM SPEAKER ILLUSTRATED) CONNECTIONS SHOWN FOR MONO WHEN MODE SWITCH IS IN THE MONO-PARALLEL POSITION SPEAKER 8
The Front Panel Controls and How to Use Them music program material. Short interval information can have a duration as short as half a thousandth of a second. Ordinarily, a meter pointer moving over its scale in such a short time would not be seen. Mclntosh has developed circuits that drive the meters to respond to the short interval information in a sound wave to an accuracy of 90%.
WATTS POWER In the WATTS position the meter's primary calibration is from .0025 watts (two and a half milliwatts), up to 250 watts, the rated power output of the MC 2255. The meter is calibrated for 500 watts at the right hand end of the meter scale. While the MC 2255 cannot reach this power level continuously, it is possible for short interval peaks to exceed, considerably, the 250 watt continuous rating. The power switch turns the MC 2255 ON or OFF.
Rear Panel information RIGHT/MONO GAIN controls in the fully clockwise position. If more gain is desired the 0.75 V position may be used. For source equipment other than Mclntosh, set the switch in the position nearest to the stated output rating of the source equipment. MODE SWITCH The MC 2255 will operate in three modes, Stereo, Mono Bridge, and Mono Parallel. The Mono modes differ in the loads they will drive and the connection sequence to the speaker terminals.
Performance Limits PERFORMANCE GUARANTEE level from 250 milliwatts to 500 watts from 20 Hz to 20,000 Hz. Performance Limits are the maximum deviation from perfection permitted for a Mclntosh instrument. We promise you the MC 2255 you buy must be capable of performance at or exceeding these limits or you get your money back. Mclntosh is the only manufacturer that makes this guarantee. INTERMODULATION DISTORTION STEREO 0.
Performance Charts FREQUENCY IN Hz FREQUENCY IN Hz PERFORMANCE CHARTS ARE FOR ONE STEREO CHANNEL WITH BOTH CHANNELS OPERATING. MONO O P E R A T I O N IS IDENTICAL EXCEPT POWER IS DOUBLED FOR THE SINGLE MONO OUTPUT.
FREQUENCY IN Hz POWER IN WATTS 14
Technical Description tion at low frequencies. A current mirror circuit combines the differential outputs into one signal which is then amplified by a following class A voltage amplifier. Both the differential transitors and the voltage amplifier are supplied by active current sources. The results are lower distortion and cleaner turn on characteristics. INPUT AMPLIFIER Each channel input contains a complete seven transistor low power amplifier.
circuit also illuminates red LIMIT indicator lamps when the amplifier is driven beyond its maximum output capacity. Power Guard prevents loudspeaker damage and eliminates harsh output distortion caused by amplifier clipping. this amplifier and goes directly to the full wave rectifiers through an attenuator which is controlled by the METER RANGE switch. The logarithmic amplifier consists of a high gain operational amplifier with a biopolar connected silicon diode pair as feedback elements.
Block Diagram 17
MclNTOSH LABORATORY INC. 2 CHAMBERS ST., BINGHAMTON, N.Y. 13903 607-723-3512 The continuous improvement of its products is the policy of Mclntosh Laboratory Incorporated who reserve the right to improve design without notice. Printed in U.S.A.
