VTL S-400 II series Owner's Manual page 20

The Balanced XLR input jack is for receiving a balanced signal from the source/preamplifier.
The Input Select switch is used to select the correct input. Move the handle towards the input to be selected.
The Phase select switch is used to select the input signal phase. Switch up for Phase 0 (Normal) and down for Phase
180 (INVERTed).
The single ended RCA input jack is for receiving a single ended signal from the source/preamplifier.
CAUTION: For best performance do not connect both single ended and balanced cables at the
same time.
The Trigger Input accepts an electrical signal command from an external component to remotely power up
or power down the amplifier. (6V to 24V, AC or DC)
The Speaker Binding Post is used to connect a loudspeaker to the amplifier. (Please note the correct phase when
connecting to the loudspeaker: Red (or +) to +, and Black (or -) to -.
Warning: The S-400 Series II amplifier is a fully balanced design with a balanced output.
Care should be taken so that neither output is ever grounded.
Warning: Do not connect a sub-woofer to the output of the amplifier unless you are sure
Please consult your authorized VTL dealer or the VTL factory customer support department if you have any
questions on the fully balanced connection of the amplifier.
The RS232 connector allows a bi-directional connection between the amplifier and a computer or central remote
system via a standard Male to Female DB9 RS232 cable, and will accept remote commands from the computer
and communicate operating status and diagnostic information back to the computer.
The Fuse/AC Panel contains the following:
S-400 Amplifier Owner's Manual
VTL
that the subwoofer input is fully balanced and that neither phase can become
grounded.
Fuse/AC Rear Panel
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