McIntosh MA6400 Owner's Manual page 9

C. POWER GUARD
Both channels of the MA6400 incorporate the Mclntosh POWER GUARD circuit which
prevents output clipping with its harsh and damaging distortion. A front panel LED Power Guard
indicator is provided for each of the channels. The LED lights whenever the Power Guard circuit
is activated for that channel. This indicates that the amplifier is producing its maximum
undistorted power output, and that you are being protected from overdrive and clipping. The
output level where Power Guard acts will be well above the rated power due to conservative
Mclntosh design philosophy.
(If the POWER GUARD indicators turn on and stay on continuously for either channel, it
indicates a problem is present. If this condition occurs, contact your Mclntosh dealer for
assistance.)
D. VOLUME / (MUTE LED)
VOLUME adjusts the volume level for the SPEAKERS 1 and 2 outputs, MAIN outputs and the
HEADPHONES. The TAPE 1 and 2 OUTPUTS are not affected by the VOLUME control.
A Red MUTE LED Just to the right of the VOLUME control turns ON to indicate the MA6400
output is MUTED. Activate the MUTE mode by pressing the MUTE pushbutton on the Hand Held
Remote Controller. Press MUTE again, press an UP or DOWN VOLUME pushbutton or press an
Input pushbutton to restore normal operation. Mute affects the SPEAKERS 1 and 2 and the MAIN
OUTPUTS. The TAPE 1 and 2 OUTPUTS and the HEADPHONES are not affected by MUTE.
E. LOUDness-BALANCE
BALANCE control, (large outer knob): Adjusts the volume of the Left and Right channels
relative to each other. The BALANCE control affects only the SPEAKERS 1 and 2 outputs, the
MAIN outputs and the HEADPHONES. The TAPE 1 and 2 OUTPUTS are not affected by the
BALANCE control.
L, (Left): Turn the control to the left to accent the left channels by reducing the volume of the
right channels.
R, (Right): Turn the control to the right to accent the right channels by reducing the volume
of the left channels
LOUDness control, (small inner knob): Provides frequency response contoured to
compensate for the behavior of the human ear at softer listening levels. At the fully
counterclockwise detent position, the frequency response is perfectly flat and the loudness
circuit components are removed from the signal path. Turn the control clockwise to modify the
frequency response in the correct proportion required for softer listening levels. The
compensated frequency response is not affected by changes in the volume control settings.
First adjust the VOLUME Control for the desired listening level, then adjust the LOUDness
Control to the setting you personally prefer.
FRONT PANEL
CONTROLS,
SWITCHES AND
PUSHBUTTONS
7