Turn On Lead; Input Section - JL Audio M400/4-24V Owner's Manual

TURN ON LEAD

The M400/4-24V uses a conventional +12 to
24V remote turn-on lead, typically controlled
by the source unit's remote turn-on output. The
amplifier will turn on when any voltage between
+12V and +24V is present at its "Remote" input
and turn off when this voltage is switched off. If
a source unit does not have a dedicated remote
turn-on output, the amplifier's turn-on lead can
be connected to +12V to +24V via a switch that
derives power from an ignition-switched circuit.
The M400/4-24V's "Remote" turn-on
connector is designed to accept 18 AWG – 12
AWG wire. To connect the remote turn-on
wire to the amplifier, first back out the set
screw on the top of the terminal block, using
the supplied 2.5mm hex wrench. Strip 1/2
inch (12mm) of wire and insert the bare wire
into the terminal block, seating it firmly so
that no bare wire is exposed. While holding
the wire in the terminal, tighten the set screw
firmly, taking care not to strip the head of the
screw and making sure that the wire (not the
insulation) is firmly gripped by the set screw.
6 | JL Audio - M400/4-24V Owner's Manual

INPUT SECTION

The M400/4-24V's input section allows you
to send signals to the amplifier section through
the use of two or four differential inputs.
Input connections are made via one or two
pairs of traditional RCA-type jacks.
If you wish to send four discrete channels into
the M400/4-24V, 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 & 2. In this mode, Channel 3 will operate
with the Channel 1 signal and Channel 4
will operate with the Channel 2 signal.
Input Voltage Range:
The M400/4-24V's input sections are designed
to accept signal voltages from 100mV – 4V. This
will accommodate all preamp level signals and
many speaker level signals.
To use speaker-level sources, simply splice the
speaker output wires of the source unit onto a
pair of RCA plugs for each input pair. (or use JL
Audio part XD-CLRAIC2-SW) No "line output
converter" is needed in most cases.
If you find that the output cannot be reduced
sufficiently with a direct speaker level signal
applied to the amplifier, you may use a "line
output converter" to reduce the signal level.