McIntosh MC2301 - Manual (Page 17)

17
amplifier. The meter pointer will then rise
to the newer higher indication. If no further
power peaks are reached, the meter pointer
will very slowly return to its rest position or
lower power level. The decay rate is approxi-
mately 6dB per minute.
Input Mode Switch
The Input Mode Switch, which is located on the Rear Panel
of the MC2301, allows you to select either the BAL (Bal-
anced) or UNBAL (Unbalanced) Input. Refer to figure 11.
Standby/Protection Indicator
The MC2301 Sentry Monitor Tube Protec-
tion Circuitry provides protection to the
Power Amplifier in the event of an imped-
ance mismatch 1 between the MC2301 and
the Loudspeaker. It will also activate if
there is a short circuit at the MC2301 Output Terminals (or
the Loudspeaker Terminals) or if a MC2301 Power Out-
put Tube should fail. During normal operation the Sentry
Monitor Tube Protection Circuitry has no effect on the
performance of the Power Amplifier.
In the event a problem occurs, the MC2301 Sentry
Monitor Tube Protection Circuitry will activate to prevent
potentially destructive high levels of current from flowing
in the amplifier. The Front Panel Standby LED will start
flashing indicating the Protection Circuitry is active. Refer
to the illustration on page 16 for the location of Standby
LED.
To reset the Sentry Monitor Tube Protection Circuitry
place the POWER Switch to the OFF position. After wait-
ing approximately one minute, place the POWER Switch
to the REMOTE or ON position.
Power On
To have the MC2301 automatically turn On or Off when
a control center turns on or off, rotate the power switch to
the remote position. For manual opera-
tion, rotate the power switch to the
On or Off position as desired. Refer to
figure 8.
Note: There must be a power control
connection between the MC2301
and the McIntosh Control Center,
in order for the remote power
turn-on to function.
Meter Selection
Rotate the meter mode switch to
select the meter operation mode
you desire. Refer to figures 9 and
10.
Lights Off - Meter lights are
turned off and the
meter will contin-
ue to indicate the
power output.
Note: When Power
Control Input of the MC2301 is connect-
ed to a McIntosh A/V Control Center or
Preamplifier with Remote Meter Illumi-
nation Control, the Meter Illumination
will automatically be remotely con-
trolled (On/Off) with the METER Switch
set to the WATTS or HOLD position.
Watts- The meter responds to all the musical infor-
mation being produced by the amplifier. It
indicates to an accuracy of at least 95% of
the power output with only a single cycle of
a 2000Hz tone burst.
Hold - The meter pointer is locked to the highest
power peak in a sequence of peaks. It is
electronically held to this power level until
a higher power peak passes through the
How to Operate
How to Operate
Figure 8
Figure 9
Figure 10
Figure 11
1 This can occur when a Loudspeaker of a given impedance
rating is connected to the MC2301 Output Terminals with a
different impedance rating. For example, a Loudspeaker with
an impedance rating of 2 Ohm is connected the MC2301 8
Ohm Output Terminals. The impedance of a Loudspeaker
actually varies as the Loudspeaker reproduces different
frequencies. As a result, the nominal impedance rating of the
Loudspeaker (usually measured at a midrange frequency)
might not always agree with the impedance of the Loud-
speaker at low frequencies where the greatest amount of
power is required.