Controlling Multiple Amplifiers With One Volume Controller - Extron electronics MPA 152 MD User Manual

Pin 3 is ground.
z z
NOTE: All nominal levels are at ± 10%

Controlling multiple amplifiers with one volume controller

Several MPA 152 MD units can be daisy-chained so that one volume controller can
simultaneously regulate the volume of all the amplifiers.
NOTE:
As additional amplifiers are added to the daisy chain, the sensitivity of the
volume potentiometer will change. The maximum volume level (fully clockwise)
will not be affected. However, the effectiveness of the minimum volume level
(fully counterclockwise) in reducing the volume to inaudible levels decreases as
more amplifiers are added to the daisy chain.
When more than two MPAs are attached to the chain, sound may begin to be
heard even if the levels have been set to their lowest. The muting of the output
can be remedied with a contact closure button attached between the Vol/Mute
and ground pin of the first MPA in the chain.
To regulate multiple amplifiers with a single volume controller, follow these instructions:
1.
Attach all three pins of the volume controller to the corresponding pins on the first
MPA 152 unit only (ground to ground; Vol/Mute to Vol/Mute; and 10 V to 10 V).
2. Use jumper wires to connect the Vol/Mute pins of the first and each successive amplifier.
3.
Use jumper wires to connect the ground pins of the first and each successive amplifier.
VOL/MUTE
Extron
10V
VCM 100 AAP
VOL/MUTE
10V 50mA
Figure 5. Regulating Multiple Amplifiers with a Single Volume Controller
CAUTION: If the MPA 152 MD is used in this configuration, it is the responsibility
of the user to ensure that the system complies with the requirements
of the IEC 60601-1-1 system standard. If there are any questions or
doubts, contact the Extron Support Department. For more information,
see the
NOTE: The 10V pin of the volume controller connects to the first MPA 152 MD
only. There are no jumper wires linking it to subsequent amplifiers.
VOL/MUTE
10V 50mA 10V
MPA 152 MD Application Notes
MPA 152 MD • Panels and Cabling
Extron
MPA 152 MD
daisy chain
VOL/MUTE
50mA
on page 1.
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