Xtant M Series - Manual (Page 14)

Deriving the mono channel is accomplished by using the left channel posi-
tive wire as the positive speaker wire and the right channel negative wire
as the negative speaker wire. It is important that a minimum 4 Ohm imped-
ance be observed.
Inputs
M Series Amplifiers feature RCA inputs only. Run RCA cables from your
sound source to the inputs of the amplifier. We suggest the use of high qual-
ity shielded RCA patch cords to help reduce or eliminate unwanted noise in
your installation. Be sure to run the RCA cables on the opposite side of the
vehicle that you used to carry the power leads to the amplifier.
The input stage of the M Series amplifiers incorporates Xtant’s Balanced
Line circuitry. This circuitry may be “enabled” or “disabled” via the
Balanced Input Mode Jumper located above the RCA input jacks. With the
Balanced Line circuitry “enabled”, the input sensitivity ranges from 100mV
to 17 Volts. When in the “disabled” mode, input sensitivity ranges from
100mV to 8 Volts. Input sensitivity is adjustable in 10 dB steps via the Input
Gain Select Jumper located above the Balanced Input Mode Jumper. Each of
the five jumper positions correlate to a specific range of input signal levels.
The chart below details the relationship between the jumper position and
input signal level.
ADJUSTING INPUT SENSITIVITY
INPUT JUMPER SIGNAL LEVEL
-20 dB = 10 to 17 Volts
-10 dB = 3 to 8 Volts
0 dB = 1 to 3 Volts
+10 dB = 300 mV to 1 Volt
+20 dB = 100 to 300 mV
The amplifier is shipped with the input gain set at the +10 dB position. If you
do not know the output signal level of your head unit and you want to
change the factory setting, simply move the jumper to the +20 dB position
to increase the gain. Move the jumper to the 0, –10 or –20 dB position to
decrease the gain.
The input circuitry operates similar to a line driver by increasing the signal
level when placed in the +10 and +20 dB positions. The following chart illus-
trates this function:
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