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VCA-MC Series
Amplifier Accessories
Operation Manual
5 Theory of Operation
The amplifier attenuator and the VCA attenuator are in series (Figure 5.1). The gain of the
series combination is the sum of both attenuator settings. For example, if the amplifier
attenuator is set at –10 dB and the VCA attenuator is set at –33.3 dB, the total attenuation is
–43.3 dB. (See the
CTs Multi-Channel Series Operation Manual
for attenuation vs. detent of
the amplifier attenuator.)
Figure 5.1 System Block Diagram
This unique design allows the system designer to limit the power available to the user of
the VCA control. In the above example, the amplifier attenuator is set at –10dB. In this con-
figuration, the VCA control can vary the total amplifier gain only from a quiet –80dB to a
maximum of –10dB. This mode of operation keeps a novice user from turning up the sys-
tem too loud and damaging the loudspeakers.
Summary of Contents for 1-VCAP
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