Xantech PA1235X User manual

INSTALLATION INSTRUCTIONS
MODEL PA1235X
12 CHANNEL POWER AMPLIFIER
TABLE OF CONTENTS
Section Title Page
SAFETY INSTRUCTIONS....................................................................................................................................2
GENERAL INFORMATION...................................................................................................................................3
PA1235X PANEL AND FEATURE DESCRIPTIONS .............................................................................................4
INSTALLATION
Physical Location And Mounting...............................................................................................................7
Connecting The PA1235X ........................................................................................................................8
Stereo Mode Connections........................................................................................................................8
Speaker Phasing......................................................................................................................................9
Bridged Mode Connections ......................................................................................................................9
Connecting The Remote On/Off Jack .....................................................................................................10
A Typical Multi-Zone System Diagram Using A PA1235X .......................................................................11
TROUBLE SHOOTING ......................................................................................................................................12
SPECIFICATIONS .............................................................................................................................................13

Page 2 Model PA1235X
© 2002 Xantech Corporation.
SAFETY INSTRUCTIONS - READ BEFORE OPERATING EQUIPMENT
CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK,
DO NOT REMOVE COVER (OR BACK)
NO USER-SERVICEABLE PARTS INSIDE
REFER SERVICING TO QUALIFIED SERVICE PERSONNEL
The lightning flash with arrowhead symbol, within an equilateral triangle,
is intended to alert the user to the presence of un-insulated “dangerous
voltage” within the product’s enclosure that may be of sufficient magnitude
to constitute a risk of electric shock to persons.
The exclamation point within an equilateral triangle is intended to alert the
user to the presence of important operating and maintenance (servicing)
instructions in the literature accompanying the appliance.
WARNING TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO
NOT EXPOSE THIS APPLIANCE TO RAIN OR MOISTURE.
This product was designed and manufactured to meet strict quality and safety standards. There are, however,
some installation and operation precautions, which you should be particularly aware of.
1. Read Instructions – All the safety and operating instructions should be read before the appliance is operated.
2. Retain Instructions – The safety and operating instructions should be retained for future reference.
3. Heed Warnings – All warnings on the appliance and in the operating instructions should be adhered to.
4. Follow Instructions – All operating and use instructions should be followed.
5. Water and Moisture – The appliance should not be used near water – for example, near a bathtub, washbowl, kitchen sink, laundry tub,
in a wet basement, or near a swimming pool, etc.
6. Carts and Stands – The appliance should be used only with a cart or stand that is recommended by the manufacturer. An appliance
and cart combination should be moved with care. Quick stops, excessive force, and uneven surfaces may cause the appliance and cart
combination to overturn.
7. Wall or Ceiling Mounting – The appliance should be mounted to a wall or ceiling only as recommended by the manufacturer.
8. Ventilation – The appliance should be situated so that its location or position does not interfere with its proper ventilation. For example,
the appliance should not be situated on a bed, sofa, rug, or similar surface that may block the ventilation openings; or, placed in a built-in
installation, such as a bookcase or cabinet that may impede the flow of air through the ventilation openings.
9. Heat – The appliance should be situated away from heat sources such as radiators, heat registers, stoves, or other appliances (including
amplifiers) that produce heat.
10. Power Sources – The appliance should be connected to a power supply only of the type described in the operating instructions or as
marked on the appliance.
11. Grounding or Polarization – Precautions should be taken so that the grounding or polarization means of an appliance is not defeated.
12. Power-Cord Protection – Power- supply cords should be routed so that they are not likely to be walked on or pinched by items placed
upon or against them, paying particular attention to cords at plugs, convenience receptacles, and the point where they exit from the
appliance.
13. Cleaning – The appliance should be cleaned only as recommended by the manufacturer.
14. Power Lines – An outdoor antenna should be located away from the power lines.
15. Nonuse Periods – The power cord of the appliance should be unplugged from the outlet when left unused for a long period of time.
16. Object and Liquid Entry – Care should be taken so that objects do not fall and liquids are not spilled into the enclosure through
openings.
17. Damage Requiring Service – The appliance should be serviced by qualified service personnel when:
A. The Power-supply cord or the plug has been damaged; or
B. Objects have fallen, or liquid has spilled into the appliance; or
C. The appliance has been exposed to rain; or
D. The appliance does not appear to operate normally or exhibits a marked change in performance; or
E. The appliance has been dropped, or the enclosure damaged.
18. Servicing – The user should not attempt to service the appliance beyond that described in the operating instructions. All other servicing
should be referred to qualified service personnel.

Model PA1235X Page 3
© 2002 Xantech Corporation.
GENERAL INFORMATION
To enhance the ease of installation and obtain optimum performance from the PA1235X, we recommend that you
first become familiar with all its features and special capabilities by studying the descriptions and instructions in
this manual.
The PA1235X was designed to meet the audio power amplifier needs of custom installed multi-zoned systems
with high sonic quality. It's 12-11-10-9-8-7-6 multi-channel capability permits a wide variety of other uses as well,
such as surround sound home theater applications. Specific features and technology are as follows:
Cost/Size Efficiency. The PA1235X features twelve 35-watt power amplifiers. This permits each PA1235X to
drive 6-zones in a multi-zone system -- each with a 35-watt stereo amplifier per zone. The rack-mount design,
plus multiple amplifiers in a single package, delivers high quality at a reasonable price.
Input Level Flexibility. The input levels are individually adjustable (per stereo pair) from a low of 0.2 volts up to 3
volts. This gives the installer the ability to adjust the overall gain of the system or zone. For instance, there may
be a need to adjust the amplifier to deliver a controlled, maximum sound level into a zone when the volume
control on the preamp is set to maximum. This would act as a volume limiter for any particular zone (i.e. to
prevent the kids from over-driving wall speakers, etc.).
PA1235X 12 CHANNEL POWER AMPLIFIER
123456
POWER
Figure 1 – The Model PA1235X
12-11-10-9-8-7-6 Output Flexibility. Each pair of amplifiers can be bridged to allow several channel and power
output capabilities. It can be configured into four power packages as follows, which gives the PA1235X added
use in many other applications, such as driving surround sound speaker systems in addition to multi-room:
x Twelve 35-watt amplifiers - 12 total.
x One 80 and ten 35-watt amplifiers - 11 total.
x Two 80 and eight 35-watt amplifiers - 10 total.
x Three 80 and six 35-watt amplifiers - 9 total.
x Four 80 and four 35-watt amplifiers - 8 total.
x Five 80 and two 35-watt amplifiers - 7 total.
x Six 80-Watt amplifiers - 6 total.
Low Impedance Capability. Each amplifier is 4-Ohm safe under music conditions in stereo mode and 8-Ohm
safe when bridged. This means, for instance, that you can drive two pairs of 8-Ohm speakers in stereo mode in
each zone with ease.
Auto Protection Circuit. Protects the PA1235X if a short circuit or very low impedance is detected at the
speaker terminals. Each amplifier pair is protected separately, with an LED indicator showing which pair is in
protection. Normal operation is restored automatically within 3 to 4 seconds after the short is removed.

Page 4 Model PA1235X
© 2002 Xantech Corporation.
Remote Master ON/OFF Jack. This jack allows the PA1235X to be powered on and off by a positive DC voltage
ranging between 4 and 30 volts (11mA @ 12 V). Specifically, it permits the 12-volt common CO (Control Output)
or zone STATUS outputs from the Xantech ZPR68 to power one or more PA1235X's ON and OFF automatically
with zone ON/OFF commands.
PA1235X PANEL AND FEATURE DESCRIPTIONS
PA1235X 12 CHANNEL POWER AMPLIFIER
123456
POWER
123456
4
2 2
3
1
Figure 2 – The Model PA1235X Front Panel – Features and Functions
1. Front Panel. 19" X 5 ¼” panel designed for mounting into a standard 19" Rack Panel.
2. Rack Panel Handles.
3. Power Switch. When pressed to the IN position, power is applied to the PA1235X [provided the rear panel
master AC LINE ON/OFF Switch, item #13, is placed in the ON (I) position]. This is the MANUAL ON
position. When pressed again, it releases to the OUT position (MANUAL OFF), turning the unit OFF.
In addition, this switch must be left in the MANUAL OFF (OUT) position to permit an external DC Control
Voltage to power the PA1235X ON and OFF. Refer to "REMOTE MASTER ON/OFF CONTROL" terminals,
item #10.
NOTE: The PA1235X may also be powered ON/OFF with an external AC line switch into which the power
cord of the PA1235X is plugged (such as the switched AC outlet of a preamp, timer, etc. with a 15 Amp
rating). For this type of operation, leave the POWER switch depressed to the MANUAL ON position.
4. Status LED Indicators. These indicators, one for each channel pair, provide the following status information:
They are off during normal operation.
If the amplifier is driven into distortion or clipping, they will indicate with a red color.

Model PA1235X Page 5
© 2002 Xantech Corporation.
-- 0
LEFT RIGHT
1
LEFT RIGHT
2
LEFT RIGHT
33
LEFT RIGHT
4
LEFT RIGHT
5
LEFT RIGHT
6
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
GROUND
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
REMOTE MASTER
ON/OFF CONTROL
5-3 VOLTS DC
+--
AC LINE
ON/OFF
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
WARNING : TO REDUCE
THE RISK OF FIRE OR
ELECTRICAL SHOCK, DO
NOT EXPOSE THIS UNIT TO
RAIN, MOISTURE OR PLACE
WATER FILLED OB ECTS ON
THE PRODUCT.
ATTENTION : RISQUE DE
CHOC ELECTRIQUE
NE PAS OUVRIR.
NO USER SERVICABLE
PARTS INSIDE.
CAUTION
NEUTRAL
FUSING
ATTENTION :
POUR UN REGLAGE
CORRECT, SE
REPORTER AU
MANUEL
DINSTRUCTIONS.
WARNING
TURN POWER
OFF BEFORE
CHANGING
MODES
WARNING
TURN POWER
OFF BEFORE
CHANGING
MODES
REFER TO OWNERS
MANUAL FOR SAFETY
INSTRUCTIONS.
THIS DEVICE COMPLIES
WITH PART 15 OF THE
FCC RULES.
OPERATION IS SUB ECT
TO THE FOLLOWING
TWO CONDITIONS: (1)
THIS DEVICE MAY NOT
CAUSE HARMFUL
INTERFERENCE, AND (2)
THIS DEVICE MUST
ACCEPT ANY
INTERFERENCE
RECEIVED,
INCLUDING
INTERFERENCE THAT
MAY CAUSE UNDESIRED
OPERATION.
FUSE
1 AMP
SLOW BLOW
AC 120V
60Hz 8.7A
1044 WATTS
MODEL PA1235X
57 7 57
8
55 75757
6
1 11 12 13 14
96969696969
Figure 3 – PA1235X Rear Panel – Features and Functions
5. Line Inputs. These RCA-type jacks are the audio inputs for each of the amplifier pairs. Connect them to the
OUTPUT jacks of the driving preamp with good quality RCA-type patch cables. Note that the inputs are
marked LEFT-1-RIGHT, LEFT-2-RIGHT, etc., signifying the stereo channel pairs. Both the LEFT and RIGHT
jacks are also active when the MODE switch (item #7) is set to the MONO or BRIDGED mode.
6. Input Level Control. This screwdriver adjustable control (for each stereo or bridged pair) allows the input
level for full rated power output to be adjusted over a range of 0.2 volts to 3 volts. Normally you would adjust
the driving preamp to maximum volume, then set this control to the maximum volume that the client desires
for a given zone or room. This prevents the system from being driven to potentially destructive power levels.
7. Mode Switch. Switches the amplifier pair between STEREO,MONO and BRIDGED modes.
a) In STEREO mode, the two amplifiers operate independently of each other for 35 Watts of output each.
b) In MONO mode, left and right input signals are summed internally for Mono output from each of the two
amplifiers. Also, either the Left or Right (item #5) input may be used if the source is already a Mono signal.
c) In BRIDGED mode, the two amplifiers are bridged for a single channel of high power output (80 Watts @ 8
Ohms). Either the Left or Right input (item #5) may be used to drive the resultant single channel amplifier.
CAUTION: Be sure to have the POWER turned OFF when changing the position of this switch and when
making the corresponding speaker connection changes (see also item #9, following).
8. Fuse. When required, replace only with a fuse of the same type and rating:
x 120 V Version: 10 A 250 VAC, SLOW BLOW.
x 240 V Version: 5 A Time-Lag 250 VAC.
x Replacement with a fuse of higher rating will not protect the amplifier and will void the warranty.
9. Speaker Terminals. These plug-in 4-terminal screw type connectors permit speaker wire sizes up to 12-
gauge. When making connections for the STEREO mode, be sure to observe the "+” and "–" polarity
markings, just under the LEFT & RIGHT markings, for each wire pair going to the speakers.

Page 6 Model PA1235X
© 2002 Xantech Corporation.
CAUTION: When making connections for the BRIDGED mode, remember, only one speaker is being
attached per amplifier pair. Be sure to observe the outer "+” and "–" polarity markings on each side of the
word "BRIDGED" on the panel above the 4-terminal connector when connecting the 2-conductor wire to the
speaker.
10. Remote Master On/Off Control. This 2-terminal connector allows the entire PA1235X to be powered ON
and OFF by a control voltage ranging between 5 and 30 Volts DC (16mA @ 12 V). Be sure to observe the
marked polarity. For instance, the 12 volt common CO (Control Output) of the Xantech ZPR68 preamp will
power the PA1235X ON and OFF automatically with the first zone ON and last zone OFF commands. The DC
Voltage must be applied continuously to retain the ON condition and drop to less than 0.5 Volt to switch to the
OFF condition.
NOTE: The front panel POWER switch (item #3) must be left in the Manual OFF (Out) position and the
Master AC Line Switch (item #17) set to ON (I) to permit the REMOTE MASTER ON/OFF CONTROL to
operate. See also CAUTION notes, Fig. 9.
11. Rear Panel ON/OFF LED. This LED indicates the power ON/OFF condition of the entire PA1235X, whether
activated by a REMOTE MASTER ON/OFF CONTROL voltage (item #13) or from the front panel POWER
switch (item # 3).
12. Grounding Screw. Provides a means for chassis connection to earth ground or to other A/V products to aid
in the reduction of system noise, etc., if needed.
13. Master AC LINE ON/OFF Switch. Turns power OFF to the entire PA1235X, regardless of Remote Master or
front panel POWER switch conditions. Must be placed in the ON (I) position for the other power switching
functions to work.
14. 3-Conductor AC Line Cord Receptacle. Standard IEC male receptacle for plug-in of a 3-conductor power
line cord. Depending on the application, plug the line cord into a switched or un-switched 120V 60 Hz AC
outlet (or 240 VAC 50 Hz on the 240 V version).

Model PA1235X Page 7
© 2002 Xantech Corporation.
INSTALLATION - PHYSICAL LOCATION AND MOUNTING
Upper shelf, component, wall, etc.
2-inch spacing
(minimum)
PA1235X
To maximize air flow, route
single large opening in lower shelf.
Keep perforations on top cover free of
obstructions for max. cooling effect.
Keep perforations on bottom
plate free of obstructions.
Convection
Airflow
Figure 4 – PA1235X Horizontal Mounting
When you mount the PA1235X, you should plan its location carefully. Pay close attention to each of the following
factors:
1. The amplifier is convection cooled. That is, it depends on the natural free flow of air up through the slot
perforations in the bottom plate, over the internal heat dissipating fins, then out the top cover, for
adequate cooling.
2. If mounted in an equipment cabinet or other confining location, allow at least 2 inches of space above the
top cover (see Fig. 4). Be sure there are large openings in the shelf below the unit and in the cabinet to
allow the entry of cool air and the escape of warm air.
Note: Do not remove feet in shelf-top installations.
3. If the cabinet contains other heat generating components or you are using several PA1235X's in a large
multi-zone system, you will have to pay even closer attention to adequate ventilation.
4. Do not hesitate to use fans (quiet, boxer type), if necessary, to ensure a constant flow of air through the
PA1235X's and the other heat generating components.
5. When mounting in a 19" (483mm) rack, adding a single RU (Rack Unit) above and below the PA1235X
will improve convection in heavy use applications.
[One Rack Unit size = 1-3/4" (44.5mm) in height].
6. In multi-zone installations, you will have large bundles of wire and cable to accommodate audio, video
and speaker connections. Be sure to allow enough room for the leads and dress them in such a manner
so as not to block airflow.
7. The PA1235X is designed for mounting into standard 19" Rack Panels or on flat horizontal surfaces.
When mounting into a 19" rack, use the rack panel cup washers and screws supplied.
NOTE: You should consider some sort of rear support for rack mounted units when used in mobile
applications or when located in seismically active areas.

Page 8 Model PA1235X
© 2002 Xantech Corporation.
CONNECTING THE PA1235X
LEFT RIGHT
1
1V
.2V3V
LEVEL
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
WARNING
TURN POWER
OFF BEFORE
CHANGING
MODES
STEREO
MONO
BRIDGED
MODE
VIDEO
AUDIO
L
R
1
RCA Type
Patch Cords
Preamp Outputs
ZPR68, etc.
PA1235X
Rear Panel
 +
Be sure speakers are
connected with correct
polarity as shown.
Wall speakers,
shelf speakers, etc.
Left Right
Set MODE
Switch to
STEREO position
 +
LEFT RIGHT
1
1V
.2V3V
LEVEL
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
WARNING
TURN POWER
OFF BEFORE
CHANGING
MODES
STEREO
MONO
BRIDGED
MODE
LEFT RIGHT
2
1V
.2V3V
LEVEL
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
STEREO
MONO
BRIDGED
MODE
VIDEO
AUDIO
L
R
1
RCA Type
Patch Cords
Preamp Outputs
ZPR68, etc.
PA1235X
Rear Panel
 +
Be sure speakers are
connected with correct
polarity as shown.
Wall speakers,
shelf speakers, etc.
Left Right
Set MODE
Switchs to
BRIDGED position
 +
Figure 5 - PA1235X Stereo Mode Connections Figure 6 – Bridged Mode Connections
When making connections to the PA1235X be sure the power cord is unplugged. Proceed as follows:
Stereo Mode Connections
1. Using good quality RCA-type patch cables connect the L and R OUTPUT jacks of the driving preamp to the
LEFT and RIGHT input jacks on the PA1235X. Do this for each amplifier pair. Refer to Fig. 5.
2. Slide the MODE switch to the STEREO position.
3. Using good quality speaker wire, connect the individual speaker leads to the 4-terminal "SPEAKER"
connectors on the PA1235X as shown.
4. The PA1235X is 4-Ohm safe in Stereo Mode. Make sure the impedance presented to the speaker terminals
by the speakers (or any combination of speakers) is 4-Ohms minimum.
5. Be sure to observe correct polarity by connecting the "+" and "–" terminal from each channel on the PA1235X
to the corresponding "+" and "–" terminals on each speaker. This will ensure correct "phasing". See Figure 5
and Speaker Phasing, following. Since the connectors are removable, you may unplug them for ease of lead
assembly.

Model PA1235X Page 9
© 2002 Xantech Corporation.
6. As a rule of thumb, use 18 gauge speaker wire for speaker runs up to 30' (9m), 16 gauge up to 70' (21m), and
14 gauge up to 150' (39m). The 4-terminal connectors accept wire sizes up to 12-gauge max.
7. Strip the insulation back about 1/4" (6mm) and twist the strands on each lead to prevent fraying.
CAUTION: After lead ends are inserted and the screws tightened down, be sure there are no free strands
that could cause shorting!
Speaker Phasing
To obtain stable imaging and full bass response, it is imperative that stereo speakers be connected "in phase"
with each other. You can verify this as follows:
a) If the "+" (positive) and "–" (negative) terminals on your speakers are correctly marked, and visible, and you
have wired the system as shown in Figs. 5 and 7, then the system will be "in phase". No further action is
required. Most manufacturers identify the positive terminal with a red binding post, a "+" sign, or a red dot.
b) If you are unsure of the markings, you can verify the phasing. Using a mono sound source, such as AM radio,
alternately reverse the leads to one of the speakers. Pick the connection that delivers a solid center image
between the speakers as well as best bass response.
Bridged Mode Connections
In general, it is recommended that the BRIDGED mode not be used in multi-room applications where
several speakers are driven through room volume controls and the like. For such applications, use the
STEREO mode. Use the BRIDGED mode for single speaker, higher power applications, such as in surround
sound systems. Use speakers with an impedance rating of 8-Ohms minimum.
To make connections for the BRIDGED mode, follow the steps given before for stereo connections, but with the
following differences:
1. You may connect the RCA-type patch cables from the OUTPUT jacks of the driving preamp or other source
to either the LEFT or the RIGHT input jacks of the bridged pair, as shown in Fig. 6. Do this for just the
amplifier pairs you wish to run in the bridged mode.
CAUTION: Be sure Power is OFF when connecting or switching the amp for BRIDGED operation.
2. Slide the MODE switch to the BRIDGED position.
NOTE: Do this only on the amplifier pairs you wish to run in the bridged mode!
3. Connect one speaker wire pair between the 4-terminal "SPEAKER" connectors on the PA1235X and the
speakers as shown in Fig. 6. Be sure to use only the two outer terminals marked "+” and "–" on the 4-
terminal connector as shown on the panel for BRIDGED connections.
NOTE: Only one speaker is connected per amplifier pair in the BRIDGED mode!
CAUTION: When operating in the BRIDGED mode (particularly when bench testing the amplifier) do not
make a ground or any other kind of connection to the amplifier speaker terminals other than those to the
individual speakers as shown. Failures caused by inappropriate connections are not covered under the
warranty.
Connecting the REMOTE ON/OFF Jack
As mentioned under "PA1235X PANEL AND FEATURE DESCRIPTIONS", the REMOTE ON/OFF jack allows the
power to the PA1235X to be turned ON and OFF by a remotely applied DC Voltage. Fig. 7 illustrates how a

Page 10 Model PA1235X
© 2002 Xantech Corporation.
PA1235X can be switched ON and OFF via the switched AC outlet on the rear of a preamplifier. When the
preamplifier Power Switch is switched ON, power is applied to the DC adapter, which in turn applies 5V to 30V
DC to the PA1235X, switching it ON. Similarly, when the preamplifier is switched OFF, the DC voltage to the
PA1235X is removed, turning it OFF.
LEFT RIGHT
2
LEFT RIGHT
33
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
REMOTE MASTER
ON/OFF CONTROL
5-3 VOLTS DC
+--
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
5V to 12 VDC Adapter,
such as a Xantech 781RG,
plugged into a Switched
AC Outlet on Preamplifier
Preamplifier, Control Center, etc.
This must be the positive (+)
lead (white striped lead on
Xantech Power Supply Adapters)
PA1235X
(portion of rear panel)
(+)
CAUTION:
You must use the included
220 ohm resistor.
Figure 7 – Using the PA1235X Remote Master On/Off Control Terminals

Model PA1235X Page 11
© 2002 Xantech Corporation.
A Multi-Zone System Diagram Using The PA1235X
Fig. 8, following, shows the PA1235X in a typical multi-room system with a Xantech ZPR68-10 Six-Zone Preamp.
In this case, the common +12V CO (control output) from the ZPR68-10 is used to remotely turn the PA1235X On
and Off. When any one of the zones is turned on, the common +12V CO goes high, turning the PA1235X On.
Similarly, when the last zone is turned OFF, the +12V CO drops to 0V and turns the PA1235X Off.
CAUTION: When powering up multiple PA1235X’s, a delay of 2 or more seconds should be incorporated
between “power on” using multiple Xantech AC2’s.
-- 0
LEFT RIGHT
1
LEFT RIGHT
2
LEFT RIGHT
33
LEFT RIGHT
4
LEFT RIGHT
5
LEFT RIGHT
6
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
1V
.2V3V
LEVEL
GROUND
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
LEFT RIGHT
SPEAKER
+-- --+
+ BRIDGED --
REMOTE MASTER
ON/OFF CONTROL
5-3 VOLTS DC
+--
AC LINE
ON/OFF
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
STEREO
MONO
BRIDGED
MODE
WARNIN G : TO REDUCE
THE RISK OF FIRE OR
ELECTRICAL SHOCK, DO
NOT EXPOSE THIS UNIT TO
RAIN, MOISTURE OR PLACE
WATER FILLED OB ECTS ON
THE PRODUCT.
ATTENTION : RISQUE DE
CHOC ELECTRIQUE
NE PAS OUVRIR.
NO USER SERVICABLE
PARTS INSIDE.
CAUTION
NEUTRAL
FUSING
ATTEN TIO N :
POUR UN REGLAGE
CORRECT, SE
REPORTER AU
MANUEL
DINSTRUCTIONS.
WARNING
TURN POWER
OFF BEFORE
CHANGING
MODES
WARNING
TURN POWER
OFF BEFORE
CHANGING
MODES
REFER TO OWNERS
MANUAL FOR SAFETY
INSTRUCTIONS.
PART NO. 03049720-001
THIS DEVICE COMPLIES
WITH PART 15 OF THE
FCC RULES.
OPERATION IS SUB ECT
TO THE FOLLOWING
TWO CONDITIONS: (1)
THIS DEVICE MAY NOT
CAUSE HARMFUL
INTERFERENCE, AND (2)
THIS DEVICE MUST
ACCEPT ANY
INTERFERENCE
RECEIVED,
INCLUDING
INTERFERENCE THAT
MAY CAUSE UNDESIRED
OPERATION.
FUSE
1 AMP
SLOW BLOW
AC 120V
60Hz 8.7A
1044 WATTS
MODEL PA1235X
LD Player
DVD Player
AM/FM Tuner
COMMON IR OUTPUTS
COMMON IR INDICATOR
VIDEO
AUDIO
L
R
VIDEO
AUDIO
L
R
ZONE CONTROL - IR INPUTS
12345678
COMMON IR LEVEL
HI
LO
SOURCE INPUTS ZONE OUTPUTS
1 2 3 4 5 6 7 8
ZONE IR OUTPUTS
12345678
123456
®
SYLMAR, CA  MADE IN U.S.A.
POWER
IR CONFIRM
CO
G
POWER
SUPPLY
ZPR68-10
SIX ZONE EIGHT SOURCE REMOTE PREAMP
+12V
GND
STATUS
IR IN
COM
PORT
LR
Plug SAT Rec'rs into
120 V AC (u
nswitch ed)
ZPR68-10 Power
Supply
RF Signal
IR Signal
Modulator
(2-Input)
LR
ZONE 4
XANTECH
S-62/64/66
Wall Speakers
LR
48 -
Dinky Link
IR Receiver
ZONE 3
LR
TV
ZONE 5
LR
ZONE 6
XANTECH
S-62/64/66
Wall Speakers
LR
ZONE 1
LR
ZONE 2
78 -8
" " Box
IR Receiver
TV
TV
SOURCE COMPONENTS
LR
A/V
Patch Cords
A/V
Patch Cords
ZONE AMPLIFIER - MODEL PA1235X
Remote
ON/OFF
RF IN
RF IN
VIDEO IN
TV
VIDEO IN
ANT. or
Cable
4-Conductor
Home Runs.
CAUTION
See
"POWER SUPPLY
CONSIDERATIONS"
in ZPR68-10
Manual, page 10.
Base
Band
Video.
Use
RG-6
Coax
2-Way
Combiner
RF
Amp
RF (TV)
Signal.
Use
RG-6
Coax
2-Conductor
Mini-Plug-
to-Stripped
Ends. Use
6015900.
Smart
Pad
2
Smart
Pad
2

To Speakers in Rooms
ZONE 1
VCR #2
SAT Rec'r #1 VLR
SAT Rec'r #2 VLR
VLR
VLR
VCR #1
To Zone IR Out 1,
ZPR68-10
VLR
VLR
CD Changer
To
Common IR Out 1,
ZPR68-10
Smart
Pad
2

Smart
Pad
2

Smart
Pad
2

283M
Blink-IR
Mouse
Emitter (8)
ZONE 2 ZONE 3 ZONE 4 ZONE 5 ZONE 6
To Zone IR Out 2,
ZPR68-10
To Zone IR Out 3,
ZPR68-10
To Zone IR Out 4,
ZPR68-10
To
Common IR Out 2,
ZPR68-10
To
Common IR Out 3,
ZPR68-10
To
Common IR Out 4,
ZPR68-10
Figure 8 – Typical Multi-Room System with a PA1235X and a ZPR68-10

Page 12 Model PA1235X
© 2002 Xantech Corporation.
TROUBLE SHOOTING
If you encounter a problem, please review the items in the following list. Be sure, in addition, to check other
system components, such as preamplifiers, CD players, speakers, speaker wiring, etc., that may be at fault.
PROBLEM PROBABLE CAUSE AND SOLUTION
Rear panel Power Indicator does not light – no sound. Check line cord for good contact in a live AC outlet. If
REMOTE ON/OFF jack is used, be sure applied
voltage is between +5V and +30V DC with proper
polarity. See Fig. 7.
No sound from CH2, CH4 or CH6 when stereo
operation is desired.
BRIDGED/STEREO switch is incorrectly set to
BRIDGED position. Set to STEREO position. See
Fig. 6.
Sound cuts in and out every 3 to 5 seconds. Speaker load impedance is less than 4-Ohms for
Stereo mode or less than 8-Ohms for Bridged mode.
Make changes in speakers as necessary to obtain
higher impedance.
PA1235X does not turn OFF when REMOTE input
voltage goes to 0 Volts.
Be sure that the POWER switch (item 3, Fig. 2) is set
to the MANUAL OFF (REMOTE ON/OFF) position.
PA1235X becomes very warm, shuts OFF, but does
not come back ON automatically.
Set POWER switch (item 3, Fig. 2) to MANUAL OFF
(OUT) position for 15 seconds, then back ON. If
REMOTE ON/OFF jack is used, unplug for 15 seconds,
then re-plug.
One or more front panel LED’s glow red. The amplifier has been driven into clipping and/or is
overheating. Correct faulty condition.

Model PA1235X Page 13
© 2002 Xantech Corporation.
SPECIFICATIONS
Number of channels 12
Power Output
Rated continuous power, each channel, all 12 channels
simultaneously driven, 20 Hz to 20kHz, at rated THD
35 Watts at 8 Ohms
Power Output
Short term continuous, each channel, 2 channels driven,
1 kHz, at rated THD
55 Watts at 8 Ohms
80 Watts at 4 Ohms
Bridged Power Output
Short term continuous, one pair driven at 1 kHz, at rated THD
150 Watts at 8 Ohms (80 Watts continuous)
Rated THD < 0.08%
Damping Factor
at 50 Hz, half rated power
> 100
S/N Ratio
A-weighted, shorted inputs, ref to rated power
> 100 dB
Frequency Response
at 1 Watt, ± 3dB
12 Hz to 55 kHz
Input Sensitivity
at rated power, stereo mode
Max: 0.5 V
Default: 1.0 V
Minimum: Off
Input Impedance Local Inputs: 22 kOhms
Power Source 120 VAC, 60 Hz
240 VAC, 50 Hz (European version)
Power Consumption No signal: 30 Watts (0.25/0.13 A)
12 Channels at 1/10 rated power: 360 Watts (3.0/1.5 A)
12 Channels at rated power: 1044 Watts (9.1/4.6 A)
6 Channels Bridged at 8.5 Watts/Chan: 720 Watts (6.0/3.0 A)
Remote On/Off and
CI Voltage/Current
+5 V to +30 VDC (16 mA at +12 VDC)
Line Fuse Rating 120 V version: 10 A Slow Blow 220 VAC.
TMRA 30° Celsius. If this temperature is exceeded, you will
need to provide additional ventilation to insure proper
operation.
240 V version: 5 A Time-Lag 250 VAC
Dimensions 19” W x 5.25” H x 15.5” D
(483 mm W x 133 mm H x 394 mm D)
Weight 36.85 lbs (16.7 kg)

Page 14 Model PA1235X
© 2002 Xantech Corporation.

Model PA1235X Page 15
© 2002 Xantech Corporation.

XANTECH CORPORATION
12950 Bradley Avenue, Sylmar CA 91342-3829
phone [phone] • fax [phone]
www.xantech.com
Part No. 08901240 Rev B 03-18-2002