McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, New York MI128 Eight Channel Power Amplifier Owner’s Manual 13903-2699 Phone: 607-723-3512 www.mcintoshlabs.
Important Safety Information is supplied in a separate document “Important Additional Operation Information Guide” Thank You Customer Service Your decision to own this McIntosh MI128 Eight Channel Power Amplifier ranks you at the very top among discriminating music listeners. You now have “The Best.” The McIntosh dedication to “Quality,” is assurance that you will receive many years of musical enjoyment from this unit. Please take a short time to read the information in this manual.
General Information, Connector and Cable Information, Introduction and Performance Features Introduction 5. In the event the MI128 Channels over heat, due to improper ventilation or Loudspeaker Impedance, the protection circuits will activate. The Front Panel Channel LED will change color and the audio will be muted. Refer to page 13. When the MI128 has returned to a safe operating temperature, the Channel(s) normal operation will resume. 6.
Dimensions Dimensions The following dimensions can assist in determining the best location for your MI128. Front View of the MI128 17-1/2" 44.5cm 3-15/32" 4-5/16" 8.8cm 11.0cm Front View of the MI128 with Side Mount Brackets 19" Side View of the MI128 48.3cm 18-1/2" 47.0cm 17-1/16" 43.3cm 3/16" .5cm Rear View of the MI128 16-1/2" 41.9cm 13-1/4" 33.7cm 4 .25" .64cm 2.0" 5.0cm 13-19/32" 34.7cm 1-5/16" 3.4cm 3-1/4" 8.
Installation 16-7/8" Installation The MI128 needs to be placed upright on its four feet. It also can be custom installed. Remove the four feet when it is custom installed and retain them with the fastening screws for possible future use. The required panel cutout, ventilation cutout and unit dimensions are shown in the drawing on the right side of this page. It is necessary to provide adequate ventilation for cool operation, ensuring long life for the MI128.
LINE UNBALANCED INPUT Audio Input Selection for each Power Amplifier Channel Each Channel of the MI128 allows selection of different Audio Signal Inputs to be Amplified after selected via the two switches. The first switch LOCAL/BUS selects between the specific Channel Unbalanced Input Jack or BUS which allows selection of the BUS Switch (1, 2, D1 or D2).
Audio Input(s) Signal Selection Channels Input Switch 1-8 Channels Mode Switch Connections for Loudspeakers (1-8) 1-2, 3-4, 5-6, 7-8 - LINE - STEREO - BUS - MONO Channels 1-8 Power Amplifiers 7
Output Plug Connection When connecting the Loudspeaker Hookup Cables to the MI128 using the supplied Loudspeaker Connection Plugs. Refer to figure 1. 1. When connecting Loudspeakers to the MI128 it is very important to use cables Figure 1 of adequate size, so there is little to no power loss in the cables. The size is specified in Gauge Numbers or AWG (American Wire Gauge). The smaller the Gauge number, the larger the wire size: Loudspeaker Cable Distance vs Wire Gauge Guide 25 feet (7.
How to Connect from a Multichannel Zone Preamplifier 5. Place the CHANNEL 1/2 and 3/4 Input Selector Switches to the “1” Position. 6. Place the CHANNEL 5/6 and 7/8 Input Selector Switches to the “2” Position. 7. Place the Analog Audio/Digital Audio CHANNEL 1/2, 3/4, 5/6 and 7/8 Input Selector Switches to the “BUS” Position. This McIntosh MI128 Power Amplifier is designed for Loudspeakers with an impedance of 4 ohms or 8 ohms. Connect a single Loudspeaker only to each Channel Output Terminals. 8.
How to Connect for Eight Zones Output Plug Connection When connecting the Loudspeaker Hookup Cables to the MI128 using the supplied Loudspeaker Connection Plugs. Refer to figure 1. 1. When connecting Loudspeakers to the MI128 it is very important to use cables Figure 1 of adequate size, so there is little to no power loss in the cables. The size is specified in Gauge Numbers or AWG (American Wire Gauge).
How to Connect for Eight Zones 7. Place the CHANNEL 1/2 and 3/4 Digital Input Selector Switches to the “D1” Position. 8. Place the CHANNEL 5/6 and 7/8 Digital Input Selector Switches to the “D2” Position. 9. Place the CHANNEL 1/2, 3/4, 5/6 and 7/8 Mode Switches in the “MONO” Position. This McIntosh MI128 Power Amplifier is designed for Loudspeakers with an impedance of 4 ohms or 8 ohms. Connect a single Loudspeaker only to each Channel Output Terminals. 10.
Front Panel Displays and Switch LED indicates various Channel 1 Circuitry Functions LED indicates various Channel 5 Circuitry Functions LED indicates various Channel 3 Circuitry Functions LED indicates various Channel 2 Circuitry Functions LED indicates various Channel 4 Circuitry Functions 12 LED Standby Power On Indicator POWER Push-Button switches AC Power On or Off LED indicates various Channel 7 Circuitry Functions LED indicates various Channel 8 Circuitry Functions LED indicates various Cha
How to Operate How to Operate Power On The LED STANDBY/ON Indicator illuminates to indicate the MI128 is connected to AC Power. To switch ON the MI128, press the POWER Push-button on the Front Panel or switch On the Audio Source Component providing there is a Power Figure 20 Control Cable Connection to the MI128. Refer to figure 20. Notes: 1. It will take about 6 seconds for initialization of the internal circuitry to take place on the MI128 when switched On. 2.
Specifications Specifications Power Output Minimum sine wave continuous average power output per channel, all channels operating is: 120 watts into a 8 ohm load 150 watts into a 4 ohm ohm load Output Load Impedance 8 and 4 ohms Rated Power Band 20Hz to 20,000Hz Total Harmonic Distortion 0.05% maximum harmonic distortion at any power level from 250 milliwatts to rated power, 20Hz to 20,000Hz Dynamic Headroom 2.1dB, 8 ohm load 3.3dB, 4 ohm load Frequency Response +0, -0.
Packing Instructions Packing Instructions In the event it is necessary to repack the equipment for shipment, the equipment must be packed exactly as shown below. It is very important that the four plastic feet are attached to the bottom of the equipment. This will ensure the proper equipment location on the bottom pad. Failure to do this will result in shipping damage. Use the original shipping carton and interior parts only if they are all in good serviceable condition.
McIntosh Laboratory, Inc. 2 Chambers Street Binghamton, NY 13903 www.mcintoshlabs.com The continuous improvement of its products is the policy of McIntosh Laboratory Incorporated who reserve the right to improve design without notice. Printed in the U.S.A. McIntosh Part No.
