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5. RCA inputs- For connecting signal patch cables (interconnects) from the
preamplifier to the amplifier to pass signal.
6. Level controls - Option available for the Reference 4420M amplifier. For
adjusting the input level to the amplifier. Explained further
on page 6.
7. Amplifier control muting input/output -
To provide remote switching of mute on/off of the amplifier.
Explained further below.
A control is provided on each Reference 4420M amplifier to allow remote switching of
mute on/off. The preamplifier’s control output, such as is provided with B&K series
preamplifiers, can be utilized to provide a control signal to the Reference 4420M. If
more than one amplifier is being controlled, the control signal can be extended to
include each successive unit by simply running an RCA type audio cable f rom the
CTRL OUT connector of the first amplifier to the CTRL IN connector of the next unit
(commonly referred to as ‘daisy chaining’). An example of how to connect two
amplifiers is illustra ted in figure B.
If a source other than a B&K series preamplifier is used to control multiple amplifiers,
only the control output voltage from the source is critical. It must be within the range, as
indicated on the rear panel, 5-24 volts DC is required. The amplifier will provide each
successive amplifier with a control voltage of 12 volts DC for reliable operation. The
amplifiers control output may be used as a source of 12 VDC @ 125 mA for other user
applications as well.