another lead from the other terminal of the
loudspeaker to the left output terminal marked for
the impedance of the speaker on the LEFT OUTPUT
terminal strip. The right channel speaker is con-
nected in the same manner to the RIGHT OUTPUT
terminal strip.
When multiple speakers are to be connected to
either or both outputs, the combined load im-
pedance must be calculated. The load must be con-
nected to the appropriate impedance tap. Use this
table to aid in selecting the correct impedance
match:
Load
impedance
in ohms
0.8 to 1.6
1.6 to 3.2
3.2 to 6.4
6.4 and up
Connect for:
1 ohm output
2 ohm output
4 ohm output
8 ohm output
If a load impedance is used that is lower than the
output impedance tap, then reduced power and pos-
sible distortion will result. If a load impedance is us-
ed that is higher than the output impedance tap,
then neither the signal nor the amplifier will be
harmed but the power available is reduced.
FOR STEREO CONSTANT VOLTAGE OPERATION:
For output
voltage of
25 volts
Connect for:
4 ohms
MONOPHONIC OR SINGLE CHANNEL OPERATION
When the MC 2155 is used as a monophonic or
single channel power amplifier the two channels are
combined to produce output up to 300 watts. The
outputs must be connected as described below.
For monophonic operation using the MONO
BRIDGE mode, output impedances of 2, 4, 8, and 16
ohms are accomodated. Output connections are
made by connecting to the output terminals as
fisted below. Note that neither output terminal is at
ground potential.
For monophonic operation using the MONO
PARALLEL mode, output impedances of ½, 1,2, and
4 ohms are accomodated. Connect as listed below.
The common output terminal is at ground potential.
Load Impedance
In Ohms
½
1
2
4
Connect - Speaker
Lead To:
Either Left or Right
Common Terminal
Either Left or Right
Common Terminal
Either Left or Right
Common Terminal
Either Left or Right
Common Terminal
C Speaker
Lead To:
Both Left and Right
1 Ohm Terminals
Both Left and Right
2 Ohm Terminals
Both Left and Right
4 Ohm Terminals
Both Left and Right
8 Ohm Terminals
FOR MONOPHONIC CONSTANT VOLTAGE LINE
OPERATION
For output
voltage of
25 volts
Connected for:
2 ohm output (mono)
Be certain that the MC 2155 is never operated in
the stereo mode with the outputs connected for
monophonic operation. Should the MODE SWITCH
be left in the STEREO position and the outputs re-
main strapped for a mono parallel load, one channel
will attempt to drive the other which causes high cir-
culating currents and overheating.
AC POWER
The MC 2155 operates on 120 volts 50/60 Hz. The
auxiliary AC OUTLET on the MC 2155 is not fused or
switched.
Load Impedance
In Ohms
2
4
8
16
Connect - Speaker
Lead To:
Left 1 Ohm Terminal
Left 2 Ohm Terminal
Left 4 Ohm Terminal
Left 8 Ohm Terminal
C Speaker
Lead To:
Right 1 Ohm Terminal
Right 2 Ohm Terminal
Right 4 Ohm Terminal
Right 8 Ohm Terminal
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