THE MclNTOSH MC 2125 SOLID STATE STEREO POWER AMPLIFIER Reading Time: 31 Minutes Price $1.
Your MC 2125 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 WARNING: TO PREVENT FIRE OR SHOCK HAZARD, DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE. FRONT PANEL INFORMATION . . . . 8 REAR PANEL INFORMATION . . . .
INPUT 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. For the normally short distances of under 20 feet between the amplifier and speaker, #18 wire or larger can be used. For distances over 20 feet between the amplifier and speaker use larger diameter wire. Select the correct size wire for the wire distance from the chart.
If a load impedance is used that is lower than the output impedance tap, then reduced power and possible distortion will result If a load impedance is used that is higher than the output impedance tap, then neither the signal nor the amplifier will be harmed but the power available is limited.
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 METERS Output power monitor meters indicate the output power of each channel. Each meter has two primary scales: WATTS and DECIBELS. With the METER RANGE switch in one of the decibel (dB) positions, peak signal readings are indicated on the lower DECIBEL scale. The meters show peak output of the monitored channel. Ordinary meters lack the capability of indicating the short interval information in a sound wave.
OUTPUT MODE The NORMAL (green) and LIMIT (red) indicators are a new Mclntosh development. As long as the amplifier operates without overload the NORMAL indicator illuminates. A waveform comparator in the MC 2125 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.
Rear Panel Information 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. nected the MODE switch is used to select the method of operation desired. INPUT In the stereo or twin amplifier mode of operation both input jacks accept signal.
Performance Limits and Ratings watts per channel from 20 Hz to 20,000 Hz, both channel operating PERFORMANCE GUARANTEE Performance Limits are the maximum deviation from perfection permitted for a Mclntosh instrument. We promise you that the MC 2125 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. MONO 0.
Technical Description INPUT AMPLIFIER Separate input amplifiers are used for the right and left channels. Each input amplifier is a two transistor feedback amplifier which has unity gain. They are used to provide high input impedance and low output impedance for driving the power amplifier sections. In addition, impedance matching is provided for the POWER GUARD system input attenuator. transistor is derived from a long time constant capacitor charging network.
applied differentially to a high gain operational amplifier where it is amplified about 100 times. The amplified control voltage is detected by a full wave bridge rectifier then enters a Schmidt trigger which is programmed to sequence the front panel indicators from NORMAL (green) to LIMIT (red) at a preset distortion level. Also built into the trigger circuit is a timing capacitor which holds the LIMIT indicator on long enough to be visible even when the duration of the overload is much shorter.
MclNTOSH LABORATORY INC. 2 CHAMBERS ST., BINGHAMTON, N. Y. 13903 607-723-3512 Design subject to change without notice. Printed in U.S.A.
