Xtant 121m, Owner'S Manual

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I N P U T V O LTA G E M U LT I P LY I N G F A C T O R
INPUT JUMPER MULTIPLYING FACTOR
+20 dB = 10
+10 dB = 3
0 dB = 1
–10 dB = .3
–20 dB = .1
(ie: A head unit with 300mV output with input jumper @ +20dB = 3 Volts input)
The input stage may be over-loaded by a high-level signal if the input
gain is set too high. If this should occur, simply reduce the input sensi-
tivity setting.
USING THE BALANCED LINE CIRCUITRY
The Balanced Line circuitry provides two unique features which add
versatility to your head unit selection. First, the Balanced Line circuitry
increases the input sensitivity to 17 Volts when receiving a signal from
a balanced source and, secondly, isolates signal ground. These two fea-
tures allow connection with OEM factory head units and high-powered
(BTL) head units. The Balanced Line circuitry will also accept a speaker
level input signal. If the head unit has a Floating Ground output, you
must “enable” the Balanced Line circuitry prior to connecting the head
unit. Failure to “enable” the Balanced Line may result in damage to the
head unit.
The Balanced Line circuitry also helps eliminate noise (ie alternator
whine) induced into the signal cables. If you are experiencing a noise
problem, simply “engage” the Balanced Line circuitry. If the problem
continues, call Xtant Technologies’ Customer Service at 602•431•8686
for assistance.
output Gain Control
The output gain (for each 2 channels) is controlled by a board-mounted
potentiometer located next to the inputs. Xtant suggests setting this
level in conjunction with any equalization or signal processing equip-
ment in the system. Upon installation of the amplifier, the output gain
control should be adjusted. Using a small flat blade screwdriver, first
turn the output gain all the way down (counter clockwise). Turn the vol-
ume on the source unit up two thirds. Then adjust the output gain con-
trol until the desired volume is obtained without audible distortion. If
more gain is desired, adjust the input gain setting to the +20 dB position
and reset the output gain. It is important to note that the output gain is
adjusted independently from the Input Gain Select.
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