11
power output with only a single cycle of a
2000Hz tone burst. Refer to figure 12.
Auto Off Switch
The MC257 incorporates Power Save Circuitry to
automatically place the MC257 into the power saving
Standby Mode approximately 30 minutes after there
has been an absence of an audio input signal.
When there is a Power Control Connection be-
tween the MC257 and a Preamplifier or A/V Control
Center with Power Save Circuitry, the AUTO OFF
Switch in the ENable position is bypassed
(located on the Rear Panel of the MC257).
Refer to figure 13.
In the event there is no Power Control
Connection and the Power Save Circuitry
is activating inappropriately relative to your specific
use of the MC257, place the AUTO OFF Switch in the
DISable position.
Note: If the Power Save Circuitry has switched Power
to the MC257 OFF, place the POWER in the OFF
Position and then in the ON position to reset the
circuitry.
Load Switch
Place the Load Impedance Switch to the 4 Ohms posi-
tion if the Loudspeakers Connected to the
MC257 are not 8 Ohms but 4 Ohms. Refer
to figure 14.
Power On
There are two ways to have AC Power switched ON to
the MC257:
REMOTE Setting
When the MC257 Power Control Con-
nection (ZA and/or ZB) receives a Power
Control Signal from a Preamplifier or
A/V Control Center, it will turn On
automatically when the MC257 POWER
Control is set to the REMOTE Setting.
Refer to figure 9.
ON Setting
When the MC257 POWER Control is
set to the ON position, it will become
active Zone A only. Refer to figure 10.
To switch the MC257 OFF, place the
POWER Control in the OFF position.
MC257 Channel Operation
There are several Channel Operation Modes. The first
operation mode is referred to as Zone A. This occurs
when the POWER Control is positioned to ON or set
to the REMOTE position and is receiving a Power
Control Signal in the ZA connector. When the MC257
is in the Zone A operation mode, the following is a list
of Channel Operations:
MC257
ZONE A CHANNEL OPERATION
Channel Number
Channel Function
1
Left Front
2
Left Back Surround
3
Right Back Surround
4
Center (Front)
5
Left Surround
6
Right Surround
7
Right Front
The other operation mode is referred to as Zone A/B
when the POWER Control is in the REMOTE posi-
tion and both the ZA and ZB connectors are receiving
Power Control Signals.
MC257
ZONE A and ZONE B OPERATION
Zone
Channel Number Channel Function
A
1
Left Front
A
4
Center (Front)
A
5
Left Surround
A
6
Right Surround
A
7
Right Front
B
2
Left
B
3
Right
Meters
Rotate the METER LIGHTS Switch to the ON posi-
tion to Illuminate the three Front Panel Meters for the
Left, Center and Right Channels. Refer to figure 11.
Lights Off - Meter lights are turned off,
the Meters will continue to
indicate the power output.
Note: When Power Control
Input of the MC257 is
connected to an Audio
Preamplifier or A/V
Control Center with Remote Meter
Illumination Control, the Meter
Illumination will automatically be
remotely controlled (On/Off).
Watts- The meters respond to all the musical infor-
mation being produced by the amplifier. They
indicate to an accuracy of at least 95% of the
How to Operate
How to Operate
Figure 10
Figure 11
Figure 9
Figure 13
2
3
Figure 14
2
3
Figure 12
