Extron Electronics MPA 152 Plus User Guide - Manual (Page 15)

Audio Output
f
Speaker receptacle — This 4‑pole, 5 mm screw lock
captive screw receptacle is used to connect the amplifier
to the speakers.
With an 8 ohm load, the amplifier produces up to 8 watts
per channel. With a 4 ohm load, the amplifier produces up
to 15 watts per channel.
See the
attention (page 5) and note (page 5) for important information about
connecting wires to captive screw connectors.
ATTENTION: Do not short the + and – outputs to each other, as this will damage
the amplifier.
RCA
Captive
Screw
TRS
+
-
Left
+
+
Right
RCA
Captive
Screw
TRS
+
-
+
+
+
+
+
+
+
+
Amp Stage
Stereo/Dual Mono Switch
Stereo
Stereo
Dual
Mono
Figure 7. MPA 152 Plus Summing Diagram
Signal flow is as follows:
1. The MPA 152 Plus sums and weights the left unbalanced signals from the TRS and
RCA receptacles. This summed, unbalanced signal is then summed with the left
balanced signal from the captive screw receptacle.
2. The right channel is handled in the same way.
3. The left and right channels are then sent to the output amplifiers in one of two ways,
depending on how the front panel switch is set.
• Stereo: The left and right channels are sent to the left and right output amplifers
respectively.
• Dual Mono: The left and right channels are summed and then the resulting mono is
fed to both of the output amplifiers.
The captive screw, RCA, and TRS inputs are buffered.
4Ω 8Ω
CLASS 2
WIRING
L R
/
OUTPUT
MPA 152 Plus • Panels and Cabling 9