Input Section; Input Voltage Range - JL Audio JD 400/4 Owner's Manual

INPUT SECTION

The JD400/4's input section allows you to send
signals to the amplifier section through the use of
two or four differential-balanced inputs.
Input connections are via two pairs of
traditional RCA-type jacks.
INPUT SECTION
CH. 1&2
If you wish to send four discrete channels into
the JD400/4, simply use all four inputs and set the
"Input Mode" switch in the "4 Ch." position.
If you wish to use only two channels of input to
deliver signal to all four amplifier channels, set the
"Input Mode" switch to "2 Ch." and use only the
inputs to channels 1 and 2. In this mode, channel
3 will operate with the channel 1 signal and
channel 4 will operate with the channel 2 signal.
JD400/4
PREOUTS
CH. 3&4 CH. 1&2 (only)

INPUT VOLTAGE RANGE

A wide range of signal input voltages
can be accommodated by the amplifier's
input section (200mV – 8V). This wide
range is split up into two sub-ranges,
accessible via the "Input Voltage" switch:
"Low": for preamp level signals
"High": for speaker level signals
The "Low" position on the "Input Voltage"
switch selects an input sensitivity range
between 200mV and 2V. This means that the
"Input Sensitivity" rotary control will operate
within that voltage window. If you are using
an aftermarket source unit, with conventional
preamp level outputs, this is the position you
should select.
The "High" position on the "Input Voltage"
INPUT SECTION PREOUTS
switch selects an input sensitivity range between
CH. 1&2 CH. 3&4 CH. 1&2 (only)
800mV and 8V for all input channels. This is
useful for certain high-output preamp level
signals as well as speaker-level output from source
units and small amplifiers. To use speaker-level
sources, splice the speaker output wires of the
source unit or small amplifier onto a pair of RCA
cables or plugs or use the JL Audio ECS Speaker
Wire to RCA adaptor (XD-CLRAIC2-SW).
Line output converters are usually not needed
with this amplifier. If you find that the output
cannot be reduced sufficiently with a direct
speaker level signal applied to the amplifier and
the "Input Voltage" switch in its "High" position,
you may use a line output converter (like the
JL Audio LoC-22) or voltage divider to reduce the
signal level.
INPUT SECTION PREOUTS
CH. 1&2 CH. 3&4 CH. 1&2 (only)
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