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ADDING ACCESSORY MODULES

The 301a is equipped with three accessory docking ports. The two

ports dedicated to the amplifier are labeled 

Amp Vert/Horiz Acc. Port

and 

Amp Vert. Acc. Port. The third 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 two accessory ports dedicated to the amplifier allow you to add

the level(s) of signal processing that your system requires. An exam-
ple 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 highest 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), a signal is still present at the RCA line outputs.

OPTIMIZING CIRCUITRY

The 301a incorporates an optimizing circuit which allows the

amplifier to produce maximum power (300 Watts) into either a 4

or 2

speaker load. To match your speaker load to the amplifier,

move the jumper labeled, 

Output Impedance, located below the

Xtant logo by the power supply capacitors, to either the 4

or 2

position. With certain speaker systems (ie 3

), both settings should

be sampled to determine the optimum load setting.

FUSING

The 301a does not have an on-board fuse. An out-board, 50

Amp fuse must be added at the positive terminal of the battery.
For added safety, an outboard 50 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 two speaker terminals provided on the 301a. Due to

the 301a’s mono design, you cannot make a bridged connection
across these terminals. Rather, the dual terminals were intended to
provide a convenient means of making a parallel connection of
multiple speakers directly at the amplifier.

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
amplifier during the fine-tuning process. With the amp playing, sim-
ply move the 

Remote Turn-On jumper to the Amp-Off position,

make your adjustments and move the jumper to the 

Enable posi-

tion 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

301a.

CONNECTION TO THE  HEAD  UNIT

The 301a is a full-range, 300 Watt mono amplifier. It is equipped with a

pair of RCA input jacks to simplify connection to a standard two or four chan-
nel head unit. The signal is summed after the preamp/signal processing stage
of the amplifier. For proper operation, both inputs must be used.

When multiple 301a’s are used in a system to power independent chan-

nels, use a “Y” jack to supply a common signal to both inputs. This will insure
maximum signal gain. When this procedure is followed, the signal available at
RCA outputs 1 & 2 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 301a 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 602•970•9900 for assistance.

OUTPUT GAIN

The output gain is controlled by a board-mounted potentiometer located

above the 

Amp Vert Acc. Port. This pot adjusts the output level of amplifier and

is adjusted independently from the 

Input Gain Select. Xtant suggests setting this

level in conjunction with any equalization or signal processing equipment in the
system.

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. Return 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 301a’s 2

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 connec-

tor 

and port are aligned when 
installing module. Reseat module 
to insure proper connection.

Alternator/System Noise

Induced noise / ground loop

“Enable” Balanced Input

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7 6 7 6   S

O U T H

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T H

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TREET

.     P

HOENIX

,   A

RIZONA

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6 0 2 . 4 3 1 . 7 6 7 6

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