User manual MCINTOSH MC2105

[. . . ] THE MCINTOSH MC 2105 SOLID STATE STEREO POWER AMPLIFIER Reading Time: 28 Minutes Price $1. 25 Your MC 2105 Stereo Power Amplifier will give you many years of pleasant and satisfactory performance. If you have any questions, please contact: CONTENTS SERVICE CONTRACT 1 2, 3 4, 5 INSTALLATION HOW TO CONNECT HOW TO USE THE DYNAMIC PEAK LOCKING METERS . 8 PERFORMANCE LIMITS AND RATINGS TYPICAL PERFORMANCE CHARTS TECHNICAL DESCRIPTION BLOCK DIAGRAM 9 . . 2 Chambers Street Binghamton, New York 13903 Phone: 607-723-3512 WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. Take Advantage of 3 years of FREE Factory Service . [. . . ] The shielded cable from the right output of the Mclntosh preamplifier is plugged into the right jack. SPEAKERS Speakers are connected at the barrier strips marked OUTPUT on the back panel of the amplifier. Use lamp cord, bell wire, or wire with similar type of insulation to connect the speakers to the amplifier. For the normally short distances of under 50 feet between the amplifier and speaker, #18 wire or larger can be used. For distances over 50 feet between the amplifier and speaker use larger wire. The loudspeaker impedance is usually identified on the loudspeaker itself. Connect one of the leads from the left loudspeaker to the screw marked COM on the LEFT OUTPUT barrier strip. Connect the other lead from the left loudspeaker to the screw marked with the number corresponding to the speaker impedance on the LEFT OUTPUT barrier strip. Connect one of the leads from the right loudspeaker to the screw marked COM on the RIGHT OUTPUT barrier strip. Connect the other lead from the right loudspeaker to the screw marked with the number corresponding to the speaker impedance on the RIGHT OUTPUT barrier strip. The only adverse effect on the operation of a Mclntosh amplifier when it is improperly matched is a reduction in the amount of distortion-free power available to the loudspeaker. Close impedance matching is desirable for maximum distortion-free power. SPEAKER CONNECTIONS Use this table to determine proper speaker connection. Connect the If the speaker impedance speaker leads is between: between COM and: 3. 2 to 6. 5 ohms 4 ohms 6. 5 to 13 ohms 8 ohms 13 to 26 ohms 16 ohms Connect as follows: Connect one right speaker Connect one lead to the If the left speaker to screw marked RIGHT-COM speaker screw LEFTand the other impedCOM and to: ance is: other to: RIGHT-4 4 ohms LEFT-4 RIGHT-8 8 ohms LEFT-8 RIGHT-16 16 ohms LEFT-16 DO NOT CONNECT A MONOPHONIC LOUDSPEAKER TO BOTH TERMINALS. For 25 volt line operation connect one of the left leads to the screw marked COM on the LEFT OUTPUT barrier strip. The other left lead is connected to the screw marked 8W on the LEFT OUTPUT barrier strip. Connect the right leads in the same manner on the RIGHT OUTPUT barrier strip. The amplifier will be turned on and off if its power cord is plugged in one of the auxiliary AC power outlets on the program source. 4 5 HOW to Use the Dynamic Peak Locking Meters Ordinary meters lack the capability of indicating the short interval power in a sound wave. The mass of the meter movement is too great to respond to instantaneous changes in music program material. Mclntosh superior engineering has developed new circuitry that permits the meters on the MC 2105 to respond to the short interval power in a sound wave to an accuracy of 98% of the true value. This is another Mclntosh development that represents a major step forward in the use of power level meters. There are two circuits that give these meters the indicating capability of the short interval power in a sound wave. The first circuit is an accelerating circuit that compensates for the inertia characteristics of the meter movement. [. . . ] Meter range switch is provided to increase meter sensitivity by 10 dB or 20 dB Calibration accuracy at 0 dB reading is ±2% at all frequencies; meter range accuracy is ±5% 9 Technical Description A two stage amplifier with three transistors in each channel increases the input voltage 16 dB. The two stage preamplifier is fed to a pair of matched transistors arranged as an emitter coupled amplifier with two inputs and one output. The signal from the preamplifier section connects to one of these inputs. This large quantity of feedback is used to reduce noise and distortion. [. . . ]