ADDING ACCESSORY MODULES
The 403a is equipped with five accessory docking ports. The four
ports dedicated to the amplifier are labeled
Amp Vert/Horiz Acc. Port
and
Amp Vert. Acc. Port. The fifth port is dedicated to the RCA line out-
puts and is labeled
Line Out Vert. Acc. Port.
Xtant offers two types of accessory modules which are designed for
either “Horizontal” or “Vertical” mounting. The docking port, located
behind the RCA line outputs, labeled
Amp Vert/Horiz Acc. Port will
accept any module, while the ports labeled “Vert” will only accept mod-
ules designed for vertical mounting.
The four accessory ports dedicated to the amplifier allow you to add
the level(s) of signal processing that your system requires. An example
would be if a
band pass function is required, a CM12H (high pass at the
lowest frequency of the band pass) and a CM12L (low pass at the high-
est frequency of the band pass) could be used to create a 12 dB per
octave band pass filter. A more basic set-up would be a PQM-1 EQ
module and a CM 12 crossover module.
The
Line Out Vert. Acc. Port will only accept one of the “vertical”
accessory modules. This will allow bass equalization or a crossover
function to be dedicated to the RCA line outputs. If a module is not used
(jumpers in place), signal is still present at the RCA outputs.
FUSING
The 403a does not have an on-board fuse. An out-board, 60 Amp
fuse must be added at the positive terminal of the battery. For
added safety, an outboard 60 Amp
service fuse may also be added
close to the amplifier.
CONNECTING THE WIRES
Xtant recommends that all wires be terminated with “spade” or “ring
“ style connectors. Care should be taken not to strip the Power,
Ground, Remote Turn-On lead and Speaker Wires over or near the
exposed circuit board. If a stray wire falls on the board and power
is applied to the amplifier, failure may occur!
There are five sets of speaker terminals provided on the 403a. The
outputs labeled
Chan 1 and 2 are a direct connection to the amplifier.
The terminals labeled
Passive Chan 1 and 2 only become active
when one of Xtant’s RM Modules is installed.on the module port
towers. These terminal are connected in parallel to the main terminals
via the RM Module.The terminals labeled mono are a direct connection
to the amplifier’s mono channel.
For high-powered, bridged operation, connect the speaker(s) to the
Channel 1 “plus” terminal and the Channel 2 “minus” terminal. The
speaker load across the bridge should be 4
Ω
or higher. With an RM
Module installed, a bridged connection can be made across the “pas-
sive” terminals. This output will be attenuated based upon the value of
the RM module installed. If a bridge connection is made across both
sets of terminals, each speaker load must be 8
Ω
or higher.
RESISTOR MODULES
The RM Modules serve two purposes – They activate the “
passive
speaker terminals” while adding attenuation to any speakers connect-
ed to these terminals. Normally, the “
passive terminals” are used for the
rear fill speakers but any speakers (ie tweeters / center channel) that
you desire to attenuate (turn down) may be connected to these termi-
nals. The RM Modules offer four levels of attenuation: -4, -8, -12, or -16
dB.The appropriate RM Module is dependent upon speaker efficiency
and the distance of the listener to the speakers. In a pick-up truck,
where the rear speakers are in relatively close proximity, the higher
value RM 12 or RM 16 may be appropriate. In a sedan or coupe, the
RM 4 or RM 8 may be better suited. The modules are easily inter-
changed and a little experimentation will help you determine the best
value.
SERVICE JUMPER
This jumper breaks the connection of the Remote Turn-On lead. It
has been provided to allow easy “turn-off” and “turn-on” of the amplifi-
er during the fine-tuning process. With the amp playing, simply move
the
Remote Turn-On jumper to Amp-Off position, make your adjust-
ments and move the jumper to the
Enable position to turn the amp back
on
installer’s reference
x t a n t t e c h n o l o g i e s
T
HIS DOCUMENT HAS BEEN CRAFTED TO MAKE INSTALLATION
,
SYSTEM
EXPANSION AND TROUBLE
-
SHOOTING
,
A QUICK AND EASY PROCESS
. T
HE
INFORMATION PROVIDED
,
SHOULD BE REVIEWED PRIOR TO INSTALLING
AND
/
OR ADJUSTING THE
403a.
CONNECTING THE HEAD UNIT
The 403a is a three channel, full-range, 400 Watt amplifier. It is equipped
with a 2 pair of RCA input jacks to simplify connection to a standard two or four
channel head unit.
Both front and rear inputs must be used when the amplifier is in the 4
channel mode. Only front inputs need be used when you select 2 channel
mode on the 2/4 channel jumper. When this procedure is followed, the signal
available at both RCA input jacks will be identical. If you intend to utilize the
amplifier’s RCA output jacks to supply a stereo signal to another amplifier, you
must supply a stereo signal to the inputs.
INPUT SENSITIVITY
The input stage of the 403a incorporates Xtant’s
Balanced Line circuitry.
This circuitry may be “enabled” or disabled (“defeat”) via the
Balanced Input
Mode Jumper located above and to the left of the RCA input jacks. With the
Balanced Line circuitry “engaged”, the input sensitivity ranges from 100 mV to
17 Volts. When in the “defeat” mode, input sensitivity ranges from 100 mV 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. A chart
detailing jumper position to input signal levels is located on the opposite side
of this “Installer’s Reference”.
The amplifier is shipped with the
Input Gain set at the +10 dB position. If
you do not know the output signal level of the 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:
INPUT VOLTAGE MULTIPLYING FACTOR
INPUT JUMPER POSITION
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 sensitivity setting.
USING THE BALANCED LINE CIRCUITRY
The
Balanced Line circuitry provides two unique features which add ver-
satility 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 features 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 prob-
lem, simply “engage” the
Balanced Line circuitry. If the problem continues, call
Xtant Technologies’ Customer Service at 888•449•8268 for assistance.
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OUTPUT GAIN
The output gain for each channel is controlled by board-mounted potentiome-
ters. These pots independently adjust the output level of each channel. Xtant sug-
gests setting this level in conjunction with any equalization or signal processing
equipment in the system. Output gain is adjusted independently from the
Input
Gain Select.
If your customer desires max output, don’t be afraid to adjust the
Input Gain
Select to +20 and turn the output gain pot wide open (full clockwise rotation). If
you should encounter distortion (input clip), turn the amp off via the
Remote Turn-
On jumper and reset your Input Gain Select to +10. Place the Remote Turn-On
jumper to the “enable” position and audition the system. Repeat this process if
distortion (input clip) continues. The object is to pass as much input signal as pos-
sible without over-loading the input stage. Finally, adjust the output pot for desired
“max” volume setting on the head unit’s volume control.
DIAGNOSTIC LED’
S
The Red LED indicates that the amplifier is on.
The Yellow LED indicates that an over-current condition (low impedance) exist
and will turn the amp’s output power down to maintain uninterrupted operation.
The Yellow LED will light if a speaker load falls below the 403a’s 2
Ω
rating and/or
a speaker lead / speaker voice coil is shorted.
The Orange LED indicates that an over-heating condition exists and will turn the
amp’s output power down to maintain uninterrupted operation. The Orange LED
will light if the heatsink temperature exceeds rated spec due to a blocked air
intake or exhaust opening. If the fan should fail, the Orange LED will also light.
TROUBLE SHOOTING
Symptom/Condition
Cause
Solution
Red LED not on. No Sound.
Loss of 12V Power at Amplifier
Check out-board fusing
Check +/– 12 Volt connections
Measure for + 12 Volts or higher
@ amp. Check Turn-On lead
Red LED on. No Sound.
No Input Signal
Check integrity of RCA cables
Check connection at amp and
head Unit.
Red LED on. No Sound.
Loose Speaker Wires
Check integrity of speaker
connection at amp and speakers.
Red LED on. No Sound.
Lack of Turn-On Voltage
Voltage @ Turn-On lead needs
to be 8 Volt minimum
Red LED on. No Sound.
Missing Accessory Port Jumper
Check Port Jumpers, two jumpers
per port are required. Check
jumper alignment, jumper must
be seated properly.
Red LED on. No Sound.
Accessory module not installed properly Be sure “key” on module
connector and port are aligned
when installing module. Reseat
module to insure proper
connection.
Alternator/System Noise
Induced noise / ground loop
“Enable” Balanced Input
x t a n t t e c h n o l o g i e s
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