THE MCINTOSH MC 2120 SOLID STATE STEREO POWER AMPLIFIER R e a d i n g Time: 29 M i n u t e s Price $1.
Your MC 2120 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 . . . . 1 INSTALLATION . . . . 2 HOW TO CONNECT . . . . 4 FRONT PANEL INFORMATION . . . . 8 WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS UNIT TO REAR PANEL INFORMATION . . . . 10 RAIN OR MOISTURE.
available from the MC 2120, be sure to use large diameter speaker leads. In all cases, the leads to and from the speaker should be twin conductor or twisted together. Use lamp cord, bell wire, or wire with similar type of insulation to connect the speakers to the amplifier. When using 8 ohm speakers and for the normally short distances of under 30 feet between the amplifier and speaker, #18 wire or larger can be used. For distances over 30 feet between the amplifier and speaker use larger diameter wire.
FOR MONOPHONIC CONSTANT VOLTAGE LINE When multiple speakers are to be connected to either or both outputs, the combined load impedance must be calculated. The load must be connected to the appropriate impedance tap. Use this table to aid in selecting the correct impedance match: Load impedance in ohms Connect tor 1.6 to 3.2 2 ohm output 3.2 to 6.
Stereophonic Connections PROGRAM SOURCE RIGHT SPEAKER MUST BE IN STEREO POSITION FOR STEREO PROGRAMS STEREO MODE SWITCH LEFT SPEAKER MONO 6
Monophonic Connections PROGRAM SOURCE STEREO CONNECT FOR MONO USE ONLY WHEN THE MODE SWITCH IS IN MONOPOSITION MODE SWITCH MONO 7
Front Panel Information LEFT GAIN Use the LEFT GAIN control to adjust the volume in the left channel to the desired listening level. Turn the control clockwise to increase the volume. RIGHT/MONO GAIN Use the RIGHT/MONO GAIN control to adjust the volume in the right channel to the desired listening level. Turn the control clockwise to increase the volume.
minates. A waveform comparator in the MC 2120 constantly compares the amplifier input and output waveform. Waveform difference of the output wave is converted to a voltage which is used as a control signal to "turn off" the NORMAL indicator and to "turn on" the LIMIT indicator. The LIMIT indicator turns on whenever the waveform difference exceeds 0.5%. Generally, these waveform differences are the result of applying voltages at the input in excess of its rating.
Rear Panel Information all of these functions. When the instrument is properly connected the MODE switch is used to select the method of operation desired. LEFT and RIGHT OUTPUT For stereo operation, output impedances of 2, 4, 8 and 16 ohms have been provided on a secure, screw type barrier strip. For monophonic operation proper interconnection provides, 1, 2, 4 and 8 ohms from the same barrier strips. INPUT In the stereo or twin amplifier mode of operation both input jacks accept signal.
Performance Limits and Ratings PERFORMANCE GUARANTEE Performance Limits are the maximum deviation from perfection permitted for a Mclntosh instrument. We promise you that the MC 2120 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. watts per channel from 20 Hz to 20,000 Hz, both channels operating MONO 0.
Performance Charts Per Channel Both Channels Operating HARMONIC DISTORTION AT RATED OUTPUT FREQUENCY RESPONSE AT 1 WATT OUTPUT POWER BANDWIDTH AT 0.
OUTPUT SIGNAL WAVEFORM SHOWING ACTION OF POWER GUARD TO ELIMINATE OUTPUT SIGNAL CLIPPING. AMPLIFIER INPUT IS OVERDRIVEN BY 20 dB FOR BOTH OSCILLOGRAM TRACES. INTERMODULATION DISTORTION VS. POWER OUTPUT HARMONIC DISTORTION VS.
Technical Description The MC 2120 has transient free turn on and turn off characteristics. This is because the output of the amplifier is switched by a heavy duty relay to the output autotransformer. The relay is driven by a transistor switch. The control signal to this transistor is derived from a long time constant capacitor charging network. The switch turns on the relay approximately two seconds after the MC 2120 is turned on.
The input waveform and the output waveform are compared in an integrated circuit differential amplifier. Any differences, due to distortion of the output waveform, are converted to a control voltage. This control voltage is applied differentially to a high gam operational amplifier where it is amplified about 100 times.
MCINTOSH LABORATORY INC. 2 CHAMBERS ST., BINGHAMTON, N. Y. 13903 607-723-3512 Design subject to change without notice. Printed in U.S.A.
