Extron electronics MPA 152 Plus User Manual page 16

Controlling multiple amplifiers with one volume controller
Several MPA 152 Plus 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
changes. The maximum volume level (fully clockwise) is not 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 amplifiers 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 C (volume or mute) and G (ground) pins of the first amplifier 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 Plus unit only:
•
Ground () to ground (G)
• Vol/Mute to C
•
10 V to V.
2. Use jumper wires to connect the C (Volume and Mute) pins of the first amplifier and each successive
amplifier.
3. Use jumper wires to connect the G (ground) pins of the first amplifier and each successive amplifier.
VOL/MUTE
Extron
VCM 100 AAP
10V
Extron
MPA 152 Plus
Daisy Chain
V C G
10V
Figure 6. Regulating Multiple Amplifiers with a Single Volume Controller
NOTE: The 10V pin of the volume controller connects to the first MPA 152 Plus only. There are no jumper
wires linking it to subsequent amplifiers.
V C G
50mA 10V 50mA
V C G
10V 50mA
MPA 152 Plus • Panels and Cabling 8