3
Power Control Connector
The MI128 Power Control Input receives an On/Off
signal from +5 to +12 volts. The Power Control Output
will in turn provide a +12 volt Output Signal with a
total current up to 50mA. An ad-
ditional connection is for controlling
the illumination of the MI128 Meter
Power Output Indicators. The 3.5mm
stereo mini phone plug connects to a
McIntosh Preamplifier or A/V Control Center Power
Control Output.
General Information, Connector and Cable Information, Introduction and Performance Features
Connector Information
Introduction
Performance Features
Power
Control
Meter
Illumination
Control Ground
Now you can take advantage of traditional McIntosh
standards of excellence in the MI128 Power Amplifier.
The Eight Channel Power Amplifier produces high
power output per channel and will drive quality Loud-
speakers to a high level of performance. The MI128
reproduction is sonically transparent and absolutely
accurate. The McIntosh Sound is “The Sound of the
Music Itself.”
• Power Output
The MI128 consists of Eight Power Amplifier Chan-
nels, each capable of 120 watts into 8 ohm or 150
watts into 4 ohm Loudspeakers with distortion less
than 0.025%.
• Loudspeaker Guard
The McIntosh Loudspeaker Guard Circuit prevents the
amplifier from being over driven into clipping, with
its harsh distorted sound that can damage your valu-
able Loudspeakers.
• Versatile Operation
The MI128 provides power amplification for up to
eight channels in a multi Zone Audio System.
• Unbalanced Inputs
There are eight Unbalanced Analog Audio Inputs for
all eight Power Amplifier Channels.
Digital Audio Inputs
The Digital Inputs decode PCM Signals from external
sources. The Optical Inputs process Digital Signals
from 32kHz to 192kHz with 24-Bit resolution.
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. If it becomes necessary to replace the Loudspeaker
Connection Plugs used on the MI128 Rear Panel,
order part number 31065800 from the McIntosh
Parts Department.
7. For additional information on the MI128 and
other McIntosh Products please visit the McIntosh
Website at www.mcintoshlabs.com.
• Sentry Monitor and Thermal Protection
McIntosh Sentry Monitor power output stage protec-
tion circuits ensure the MI128 will have a long and
trouble free operating life. Built-in Thermal Protection
circuits guard against overheating.
• Power Control
The McIntosh Power Control Circuit allows for remote
turn-on of the MI128 Power Amplifier from a McIn-
tosh A/V Control Center or Preamplifier for a single
or dual Zone System.
• Special Power Supply
A regulated Power Supply ensures stable noise free
operation even though the power line varies.
• LED Solid State Front Panel Illumination
The even Illumination of the Front Panel is accom-
plished by extra long life Light Emitting Diodes
(LEDs). The Metal and Glass Front Panel ensures the
pristine beauty of the MI128 will be retained for many
years.
