Extron Electronics MPA 401 Series User Guide - Manual (Page 14)

Controlling multiple amplifiers with one volume controller
Several MPA 401 units can be daisy-chained so that one volume controller can
simultaneously regulate the volume of all the amplifiers.
NOTES:
• 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
however 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 401 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 amplifier and each
successive amplifier.
3. Use jumper wires to connect the ground pins of the first amplifier and each
successive amplifier.
10V
VOL/MUTE
Extron
VCM 100 AAP Extron
MPA 401
daisy chain
V C G
10V 50mA
REMOTE
V C G
10V 50mA
REMOTE
V C G
10V 50mA
REMOTE
10V
VOL/MUTE
50mA 10V
VOL/MUTE
50mA 10V
VOL/MUTE
50mA
OR
Figure 5. Regulating Multiple Amplifiers with a Single Volume Controller
NOTE: The 10V pin of the volume controller connects to the first MPA 401 only.
There are no jumper wires linking it to subsequent amplifiers.
MPA 401-70V and MPA 401-100V • Rear Panel and Cabling 8