INSTALLATION INSTRUCTIONS
PA1235
2 CHANNEL POWER AMPLIFIER
1
2
3
4
5
6
POWER
PA1235 12 CHANNEL POWER AMPLIFIER
Fig. 1 The Model PA1235
GENERAL INFORMATION
ToenhancetheeaseofinstallationandobtainoptimumperformancefromthePA1235, werecommendthat
you first become familiar with all its features and special capabilities by studying the descriptions and
instructions in this manual.
The PA1235 was designed to meet the audio power amplifier needs of custom installed multi-room, multi-
zoned systems with high sonic quality. Common and Local IR control of Volume, Mute, Balance and OFF,
for each channel pair, is provided. It's bridgeable 12-11-10-9-8-7-6 multichannel capability permits a wide
variety of uses, such as enough channels to run surround sound home theater and multi-room applications
simultaneously. Specific features and technology are as follows:
• Cost/Size Efficiency. The PA1235 features 12 conservatively rated 35-watt power amplifiers. This
permits each PA1235 to drive 6-zones in a multi-zone system, each with a 35 watts/channel stereo
amplifier per zone. The rack mountable low profile design, using a large single multiple filtered power
supply, delivers high quality at a reasonable price.
• IR Controlled Volume Level. Volume can be ramped from zero output to maximum for individual
channel pairs, or, as group through the Common Bus inputs, using IR volume control commands from
an RC68+ (or RC68). The maximum input sensitivity at full volume is 0.15 volts for rated output (35
Watts/chan.).
• Local or Common Bus. Each stereo pair can be fed audio individually via their LOCAL inputs from
differing zones or sources. In addition, a single source can be fed, via the COMMON Bus, to some or
all stereo pairs as desired. This flexibility permits the installer to drive as many as six rooms in stereo
as a single zone system, or six rooms in stereo as a six zone system --- or divide them up for a
combination of both.
• Volume Setting Capabilities. The installer has the option of using the volume control of the PA1235
as the sole volume control for a zone or the system, or to adjust the PA1235 volume to a desired fixed
level and use the volume action of a connected preamp instead.
• Max-V Setting. This allows the amplifier to be set to deliver a controlled maximum sound level into a
zone when the volume is ramped to maximum. This acts as a volume limiter for the system (e.g. to
prevent the kids from over-driving wall speakers, etc.).
®
1
Download from Www.Somanuals.com. All Manuals Search And Download.
In addition, this switch must be left in the MANUAL OFF (OUT) position to permit an external DC
Control Voltage to power the PA1235 ON and OFF.
Refer to "REMOTE MASTER ON/OFF CONTROL" terminals, item #13.
NOTE: The PA1235 may also be powered ON/OFF with an external AC line switch into which the
power cord of the PA1235 is plugged (such as the switched AC outlet of a preamp, timer, etc.).
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:
a) They show Power ON/OFF and Standby ON/OFF conditions.
b) They flash Amber 5 times during power up, then turn steady Green when Power On Mute releases.
On power down, they flash Amber once, then go off.
This action occurs whether the unit is powered ON and OFF by the POWER switch (item # 3) or
by a DC voltage applied to the REMOTE MASTER ON/OFF CONTROL terminals (item #13). Be
sure the rear panel master AC LINE ON/OFF Switch, item #17, is set to the ON (I) position for the
above to occur.
c) They will go Off when the Standby OFF IR command is received. Sending a MUTE OFF command
will restore operation. Also, LEDs blink with Volume action.
d) A Mute command will cause them to blink Green (Red if Volume is within 5 dB of Max-V). Mute
is released when any other PA1235 command is sent.
e) Changing an IR Code Group will cause them to blink Amber, confirming the change has taken
effect.
f) When the volume level is increased to a range within 5 dB of MAX-V, the LED color changes from
Green to Red. NOTE: Red indicates that volume is approaching maximum --- not an indication
of power output level.
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. COMMON BUS / LOCAL Switch. Switches the amplifier stereo pair inputs between the LOCAL
(LEFT/RIGHT) jacks, item #5 and the COMMON AUDIO BUS (LEFT/RIGHT) jacks, item #8. In this
way, each amplifier pair can be driven by separate zones or sources or from a common source via the
COMMON AUDIO BUS.
7. MODE Switch. Switches the amplifier pair between STEREO, MONO and BRIDGED modes.
In STEREO mode, the two amplifiers operate independently of each other for 35 Watts of output each,
except IR control of Volume, Max-V, Mute, Standby OFF/ON and Balance functions is common to
both.
In MONO mode, left and right input signals are summed internally for Mono output from each of the
twoamplifiers. Also, eithertheLeftorRight(item#5)inputmaybeusedifthesourceisalreadyaMono
signal.
InBRIDGEDmode, thetwoamplifiersarebridgedforasinglechannelofhighpoweroutput(150Watts
@ 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 #12, following).
®
3
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
10
8
9
5
6
7
5
6
7
5
6
7
5
6
7
5
6
7
5
6
7
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
®
SYLMAR, CA
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
COMMON AUDIO
BUS
AC 120V 60 HZ
4 AMP
1
2
3
4
5
6
FUSE
10 AMP
SLOW BLOW
CAUTION
WARNING
WARNING
WARNING
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
RISK OF ELECTRIC
MODE
MODE
MODE
MODE
MODE
MODE
TURN POWER
OFF BEFORE
CHANGING
MODES
TURN POWER
OFF BEFORE
CHANGING
MODES
TURN POWER
OFF BEFORE
CHANGING
MODES
SHOCK. DO NOT OPEN
LEFT
RIGHT
LEVEL
RESET
REMOTE MASTER
ON/OFF CONTROL
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
--
+
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
5-30 VOLTS DC
AC LINE
ON/OFF
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
--
0
11 12
12
11 12
11 12
11 12
11 12
11
13 14
15 16
18
17
Fig. 3 PA1235 Rear Panel – Features and Functions
8. COMMON AUDIO BUS. A single audio source, such as from a connected preamp, can drive one or
more of the amplifier pairs simultaneously, as desired, from this Bus. Any of the amplifier pairs can
be switched to the COMMON AUDIO BUS at will by use of the COMMON BUS / LOCAL Switch (see
also item #6).
9. LEVEL (System) RESET Button. Pressing this button 2 times within 1 second restores all Factory
Default settings. The Factory Defaults for all channels are as follows:
- Input Level set to 1 Volt rms for 35 Watts output.
- Balance centered.
- Mute OFF.
- MAX-V Cleared.
- IR Code Group set to A0.
- CI (control in) disabled. Chantes CI control to IR control of Standby ON/OFF. (CI enables when +5
to +30 VDC is applied to CI for 2 or more seconds. See also item #11)
NOTE: ThePA1235willalwaysreturntolastsetvalues(plusanyunalteredfactorydefaults)aftermain
power shut down or after any power interruptions.
10. FUSE. When required, replace only with a fuse of the same type and rating:
120 V Version: 10 AMP 220 VAC, SLOW BLOW.
240 V Version: 5 A Time-Lag 250 VAC.
Replacement with a fuse of higher rating will not protect the amplifier and will void the warranty.
11. IR IN, STATUS, GROUND and CI Terminals. Removable 4-Terminal screw type plug-in connector.
IR IN = IR Signal. Receives IR Input from Xantech IR Receivers, Smart Pads, Connecting Blocks, etc.
STATUS Out. Delivers a constant +12 VDC output (9V @ 70 mA) with ON condition. 0 Volts output
= OFF (Standby).
GROUND. Ground for IR IN, STATUS out & CI in.
CI = Control Input. Use for control of Standby ON/OFF of amplifier pairs, if desired, instead of by IR.
After CI is enabled (see item #9), 0 Volts input = OFF (Standby) condition and +5 to +30 VDC input
= ON condition. (12V in draws 16 mA).
NOTE: All plug-in connectors accept wire sizes from 24 to 12 gauge.
®
4
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
12. 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.
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
oftheword"BRIDGED"onthepanelabovethe4-terminalconnectorwhenconnectingthe2-conductor
wire to the speaker.
13. REMOTE MASTER ON/OFF CONTROL. This 2-terminal connector allows the entire PA1235 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 PA1235 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.
14. Rear Panel ON/OFF LED. This LED indicates the power ON/OFF condition of the entire PA1235,
whether activated by a REMOTE MASTER ON/OFF CONTROL voltage (item #13) or from the front
panel POWER switch (item # 3).
15. Common IR IN and STATUS Connector. This 4-terminal connector provides the same type of IR
control functions as that of the individual amplifier pairs (item #11) except they apply to all amplifier
pairs in common. That is, IR commands for Volume, Mute, etc., control all amplifier pairs together.
NOTE: Individual control of amplifier pairs is possible, however, through the Common IR IN, provided
the IR Code Group is changed on amplifier pairs you wish to control separately.
The STATUS output goes high and low with the AC Power ON/OFF state of the entire PA1235. It does
not respond to a Common IR OFF/ON (Standby) condition.
16. 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., where needed.
17. Master AC LINE ON/OFF Switch. Turns power OFF to the entire PA1235, regardless of IR, Control
IN, or front panel POWER switch conditions. Must be placed in the ON (I) position for the other power
switching functions to work.
18. 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).
RC68+ (or RC68) PROGRAMMER / REMOTE CONTROL
The RC68+ Programmer (available separately) contains all the commands necessary to operate the IR
control functions of the PA1235.
• You will need it to program universal learning devices such as the Xantech URC-2 learning remote, the
Xantech Smart Pads, the 590 Programmable Controller, the 710 Fone Link, etc., with commands that
operate the PA1235.
• NOTE: The RC68+ codes operate many other Xantech models as well, such as the RGC11, CC12,
ZPR68, etc. Therefore, only the button descriptions that apply to the operation of the PA1235 are
listed below. All others should be ignored.
CAUTION: While the RC68+ can be used as a handheld remote control, it is highly recommended it
not be given to the final user for the following reasons:
®
5
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
• Since it includes adjustable code groups, the user may inadvertently alter the installer configurations.
• Also,sincetheuserwillrequireIRcommandsfromotherbrandsofequipmenttocontrolthetotalsystem,
in addition to those of the PA1235, all commands should be consolidated into one learning device, for
ease of use.
APPLICABLE RC68+ BUTTON DESCRIPTIONS
1. IR Emitter Lens.
2. Instant Volume Presets. These commands allow ran-
dom access or direct preset activation of any of 12 fixed
preset levels on the PA1235. This is useful when setting
1
up "audio scene" ambiance levels for rooms or partial
mute actions.
10
The RC68+ buttons that select a fixed level attenuation
below Max. volume are as follows:
A
A
B
C
ADJ-OFF
80
48
10
90
01
41
21
61
09
29
69
49
E9
79
F9
1
2
3
4
00
C0
50
D0
RC68+ Button
38 (Mute ON)
10 (C & 01 on RC68)
00 (1)
PA1235LevelAttenuationindB
INPUT
5
6
7
8
2
40
A0
30
B0
9
> 90 (Min. Volume)
GLOBAL
20
E0
70
F0
60
TREBLE BASS
VOL
Z-ADJ
8
7
60
88
18
98
52
MUTE
08
A8
38
B8
C0(2)
44
ON
OFF
28
E8
78
F8
50 (3)
36
E-FLAT
LAST
MAX-V
TRIM
68
C8
89
19
99
58
D8
A9
39
3
D0(4)
30
OFF
C-BAL
6
5
E1
71
F1
C9
59
D9
40 (5)
24
A0 (6)
18
4
B9
30 (7)
14
B0 (8)
10
20 (Treble Up Arrow)
E0 (Bass Up Arrow)
6
0 (Max. Volume)
3. OFF Command. Turns the amplifier pairs (both LOCAL
and COMMON) to Standby OFF mode. The "Standby
OFF" mode remains until the MUTE OFF command is
sent.
RC68+ PROGRAMMER
NOTE: This command is inhibited automatically when
the CI terminal is driven high with an external control
voltage. Refer also to items 9 and 11, Fig. 3.
Fig. 4 The RC68+ Programmer
4. C-BALCommand. InstantlyreturnsthebalancetotheCenterposition(equalvolumeineachchannel)
from any previous setting.
5. Balance Commands. When the Balance "arrow" buttons are pressed, the audio output will move to
the left or right (with a 2 dB/step reduction in the attenuated channel) with each left or right press.
NOTE: These commands do not ramp. That is, no change will occur if the BALANCE buttons
are held down continuously!
6. MAX-V. This command saves a maximum desired volume level for a zone or rooms (both LOCAL and
COMMON). The volume is first adjusted to what is desired as a maximum level. The MAX-V button
is then pressed, locking in this setting. This acts as a volume limiter for the system (e.g. to prevent
the kids from over-driving wall speakers, etc.).
To unlock the MAX-V setting, press the ADJ-OFF button (item #10).
®
6
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
7. MUTE ON/OFF. Separate ON / OFF Mute commands give positive mute action without knowing the
actual mute status. This is very helpful in a remote room where commands are sent “blind” without
any visual aids for status.
NOTE: In addition to MUTE OFF, the muted condition can be released with VOLume (item #8), Preset
Level (item #2) and Balance (items #4 & 5) commands.
8. VOLume Up/Down Commands. When pressed in individual steps, volume increase and decrease is
2 dB per step over a range of 0 dB (Max.) to -60 dB. The next step below -60 dB is OFF (> -90 dB).
When pressed continuously, volume level will change (ramp) continuously in 1 dB steps. See also
MAX-V settings (item 6).
NOTE: Volume action of the PA1235 has been designed specifically to ramp more quickly in the
DOWN direction and more slowly in the UP direction.
9. Code Group Numbers. The PA1235 is capable of being set to 55 different code groups, both
individually as amplifier pairs and collectively as a group.
NOTE: As shipped from the factory, all amplifier pairs in the PA1235 are set to code group number
A0.
Be sure to set the RC68+ to the same number!
It may be necessary to change the PA1235 amplifier pairs to different code groups if you wish to
address each pair individually from the COMMON IR BUS (item #15, Fig. 3) or an external common
IR bus network when using other Xantech PA1235's in large systems, to avoid mutual interaction.
Refer to the RC68+ instructions for code group setting procedures.
10. ADJ-OFF Command. This command unlocks a previous MAX-V setting. See also item #6.
INSTALLATION
PHYSICAL LOCATION AND MOUNTING
When you mount the PA1235, 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.
Upper shelf, component, wall, etc.
2-inch spacing
Keep perforations on top cover free of
obstructions for max. cooling effect.
(minimum)
PA1235
Keep perforations on bottom
plate free of obstructions.
Convection
Airflow
To maximize air flow, route
single large opening in lower shelf.
Fig. 5 Horizontal Mounting
PA1235
®
7
Download from Www.Somanuals.com. All Manuals Search And Download.
2. If mounted in an equipment cabinet or other confining location, allow at least 2 inches of space above
thetopcover(seeFig.4). Besuretherearelargeopeningsintheshelfbelowtheunitandinthecabinet
to allow the entry of cool air and the escape of warm air.
3. If the cabinet contains other heat generating components or you are using several PA1235'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 PA1235'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 PA1235
will improve convection in heavy use applications.
[One Rack Unit size = 1-3/4" (44.5mm) in height].
Preamp Outputs
ZPR68, etc.
6. The PA1235 will operate when mounted either horizontally or
VIDEO
vertically. Horizontal placement is preferred, however, since it
will run approximately 5% to 10% cooler when so oriented.
RCA Type
Patch Cords
L
7. In multi-zone installations, you will have large bundles of wire
and cable to accommodate audio, video and speaker connec-
tions. Be sure to allow enough room for the leads and dress
them in such a manner so as not to block airflow.
AUDIO
R
1
8. The PA1235 is designed for mounting into standard 19" Rack
Panels or on flat horizontal surfaces. When mounting into a
19"rack, usetherackpanelcupwashersandscrewssupplied.
Set MODE
Switch to
STEREO position
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.
COMMON BUS
PA1235
Rear Panel
LEFT
LOCAL RIGHT
1
CONNECTING THE PA1235
WARNING
STEREO
MONO
BRIDGED
MODE
When making connections to the PA1235 be sure the power cord is
unplugged. Proceed as follows:
TURN POWER
OFF BEFORE
CHANGING
MODES
Stereo Mode Connections
1. Using good quality RCA-type patch cables, connect the L and
ROUTPUTjacksofthedrivingpreamptotheLEFTandRIGHT
input jacks on the PA1235. Do this for each amplifier pair.
Refer to Fig. 6.
+
BRIDGED --
SPEAKER
LEFT RIGHT
+
2. Slide the MODE switch to the STEREO position.
-- --
+
3. Usinggoodqualityspeakerwire,connecttheindividual speaker
leadstothe4-terminal"SPEAKER"connectorsonthePA1235
as shown.
4. The PA1235 is 4-Ohm safe in Stereo Mode. Make sure the
impedance presented to the speaker terminals by the speak-
ers (or any combination of speakers) is 4-Ohms minimum.
Be sure speakers are
connected with correct
polarity as shown.
5. Be sure to observe correct polarity by connecting the "+" and
"–" terminal from each channel on the PA1235 to the corre-
sponding "+" and "–" terminals on each speaker. This will
ensure correct "phasing". See Fig. 6 and Speaker Phasing,
following.
– +
– +
Wall speakers,
shelf speakers, etc.
Since the connectors are removable, you may unplug them for
ease of lead assembly.
Left
Right
Fig. 6 STEREO Mode Connections
®
8
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
6. Asaruleofthumb,use18gaugespeakerwireforspeakerrunsupto30'(9m),16gaugeupto70'(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,
andyouhavewiredthesystemasshowninFigs.6and7,thenthesystemwillbe"inphase". Nofurther
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
Preamp Outputs
ZPR68, etc.
VIDEO
speakers. Pick the connection that delivers a solid
center image between the speakers as well as best
bass response.
RCA Type
Patch Cords
L
AUDIO
Bridged Mode Connections
R
Set MODE
Switches to
BRIDGED position
In general, it is recommended that the BRIDGED mode
not be used in multi-room applications where several
speakersaredriventhroughroomvolumecontrolsand
the like.
PA1235
Rear Panel
1
COMMON BUS
COMMON BUS
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.
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
1
2
WARNING
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
MODE
MODE
TURN POWER
OFF BEFORE
CHANGING
MODES
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. 7.
+
BRIDGED --
+
BRIDGED --
SPEAKER
LEFT
+
SPEAKER
LEFT RIGHT
+
RIGHT
-- --
+
-- --
+
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.
Be sure speakers are
connected with correct
polarity as shown.
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!
+
–
– +
Speaker Systems
3. Connectonespeakerwirepairbetweenthe4-terminal
"SPEAKER"connectorsonthePA1235andthespeak-
ers as shown in Fig. 7. Be sure to use only the two
outer terminals marked "+" and "–" on the 4-terminal
connector as shown on the panel for BRIDGED con-
nections.
Right
Left
Fig. 7 BRIDGED Mode Connections
®
9
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
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.
TYPICAL APPLICATIONS
Since the PA1235 has an IR control system for each amplifier pair, it can be configured so that each
individualroom, inamulti-roomsystem, canhaveLineLevelVolume, Mute, Balance, andStandbyON/OFF
action via IR or Smart Pad control. This eliminates the need for speaker level volume controls and their
attendant power losses and reduced sound quality.
A Basic Common IR Bus System - Dedicated Keypads and Remotes.
A typical system using a low cost approach is shown in Fig. 8. It does require that a dedicated remote be
used in each room that has an IR receiver - that is, remote commands for Volume, etc., are specific for each
room.
The system is configured as follows:
1. An RS41AV is used as a low cost 4-source selector, an ideal solution when only a few sources are
desired.
2. Both IR receivers and keypads are used for system control from designated rooms.
3. ACB18isusedasaconvenientparallelconnectingblockforthecommon+12VDC,IRsignalandGND
bus wiring for all the home-runs from the keypads and IR receivers in the remote rooms.
4. TheCommonIRistakenfromthe#6connectorontheCB18(connectiontoanyoftheotherconnectors
would also work) & run to the Common IR IN on the PA1235 with a 2-conductor lead. Refer to Fig. 8.
5. To provide common IR control to the RS41AV and the Source Components and to power the keypads
and IR receivers, three leads are connected between the CB18 and a 789-44 Connecting Block.
6. Since a common IR bus is used to keep costs low, each of the amplifier pairs on the PA1235 must be
set to a different IR Code Group number, so that Volume, Mute, Balance and Standby ON/OFF in
each room can be adjusted independent of the others.
To make Code Group changes, refer to the RC68+ Programmer Instructions.
NOTE: When shipped from the factory, all amplifier pairs of the PA1235 are set to Code Group
number A0. You may, for example, leave the #1 amplifier pair at A0 and change the other five
to B0, C0, D0, etc. Just be sure not to use a group number that is used by any other Xantech
product connected on the same IR bus (e.g. #20 used on the RS41AV).
CAUTION: When changing the group numbers, you must connect an IR receiver to each
amplifier pair's IR input (item 11, Fig. 3) one at a time. You cannot use the Common IR Input
(item 15, Fig. 3) as this will change them all to a different, but same number.
7. After the Code Groups are set up, "teach" volume and other commands from the RC68+ Programmer
(Fig. 4) into learning remote controls (and the keypads) dedicated to each room. Be sure to set the
RC68+ to the specific Code Group Number that corresponds to the ones chosen for each of the
amplifier pairs, during this "teaching" process.
NOTE: With a Common IR Bus system, you cannot carry the same remote control from room-
to-room. Youmustuseadedicatedlearningremote(suchastheXantechURCversions) foreach
room into which you have "taught" the specific RC68+ Code Group that operates the specific
PA1235 Amplifier Pair that controls the volume, etc., for that room!
If you wish to carry remotes that have the same codes from room-to-room, use a Dedicated IR System
as shown in Fig. 10.
®
10
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
CONTROLLED SOURCE COMPONENTS
Cassette DecK
CD Changer
Satellite Receiver
AM/FM Tuner
L
R
L
R
V
L
R
L
R
286M Dual Blink-IR™
Mouse Emitters (2)
RCA type Patch Cords
IR Signal
6015900
To Video Distribution (if used)
3.5mm to-stripped-ends
mono cable (7)
RS41AV
1
2
3
4
RS41AV
Audio/Video
VIDEO
IR
REMOTE SWITCHER
Remote Switcher
CONFIRM
®
EMITTERS
SYLMAR, CA
•
MADE IN U.S.A.
AUDIO
LEFT
789-44
CONNECTING BLOCK
782
Type
®
AUDIO
RIGHT
POWER 15VAC
V
V
G
IR IN
RS41AV
Power
Supply
Power
Supply
INPUT
OUTPUT
IR
RCVR
12VDC
White
striped
side
To AC MAINS
(Unswitched)
To AC MAINS
(Unswitched)
PA1235 (rear panel)
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
®
SYLMAR, CA
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
2
LEFT
LOCAL RIGHT
3
LEFT
LOCAL RIGHT
4
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
COMMON AUDIO
BUS
AC 120V 60 HZ
4 AMP
1
5
6
FUSE
10 AMP
SLOW BLOW
CAUTION
WARNING
WARNING
WARNING
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
RISK OF ELECTRIC
SHOCK. DO NOT OPEN
MODE
MODE
MODE
MODE
MODE
MODE
TURN POWER
OFF BEFORE
CHANGING
MODES
TURN POWER
OFF BEFORE
CHANGING
MODES
TURN POWER
OFF BEFORE
CHANGING
MODES
LEFT
RIGHT
LEVEL
RESET
REMOTE MASTER
ON/OFF CONTROL
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
--
+
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
5-30 VOLTS DC
AC LINE
ON/OFF
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
--
0
TO ROOM 1
SPEAKERS
TO ROOM 2
SPEAKERS
TO ROOM 3
SPEAKERS
TO ROOM 4
SPEAKERS
TO ROOM 5
SPEAKERS
TO ROOM 6
SPEAKERS
+12V IR
CB18
Parallel Connecting Block
+12 VDC
IR
1
2
3
4
5
6
7
8
9
GND
To AC MAINS
(Unswitched)
GND
L
R
L
R
L
R
V
G
ST
IR
V
G
ST
IR
V
G
ST
IR
Smart
Pad3™
Smart
Pad3™
Smart
Pad3™
ROOM 5
ROOM 3
ROOM 1
L
R
L
R
L
R
V
G
ST
IR
V
G
ST
IR
V
G
ST
IR
780-80
780-80
780-80
"J" Box
IR Receiver
"J" Box
IR Receiver
"J" Box
IR Receiver
ROOM 2
ROOM 4
ROOM 6
Fig. 8 Basic PA1235/RS41 System - Requires Room Dedicated Remotes
®
11
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
8. To keep the system cost low, no AC power management is included. The user would need to operate
the power switching for each component individually, using front panel power switches, or IR, as
appropriate.
IndividualroomStandbyON/OFFisprovided, however. TheSTATUSofStandbyON/OFFisindicated
at the IR receivers and keypads via the STATUS line connection to each room, as shown.
9. This system is primarily set up to distribute music to each room. A video feed to a single room could
also be done at low cost. However, video distribution to all rooms would add additional layers of
complexity and cost that would best be handled by a ZPR68-10 in a system similar to that shown in
Fig. 11.
10. When connecting speakers for each room, be sure to observe correct polarities as shown in Fig. 6.
A Basic Dedicated IR System - Non Dedicated Keypads and Remotes.
A typical system of this type is shown in Fig. 10, where each remote room has a Dedicated IR path going
to the PA1235 amplifier pair that controls it. The IR bus is not connected in common as it is in Fig. 8. It
eliminates the need for dedicated remotes, allowing you to carry the same remote(s) from room-to-
room - that is, remote commands for Volume, Mute, etc., will work in any room from the same remote.
This system is similar in many respects to the previous system (Fig. 8), but differs as follows:
1. A 796-20 Six Zone Connecting Block is used to "zone" individual IR control signals to each amplifier
pair of the PA1235 for Volume, Mute, Balance and Standby ON/OFF action in each room. It also
carries a "COMMON" IR signal to a 789-44 Connecting Block for control of the RS41AV Remote
Switcher and the Source Components.
2. Note that the ZONE numbers on the 796-20 do not agree with the room or amplifier pair numbers. This
isofnoconsequence;itisonlynecessarythateachroom'skeypadorIRreceiverconnectstoadifferent
ZONE IR INPUT on the 796-20.
3. Since the 796-20 channels the IR from each room to it's specific PA1235 amplifier pair, each amplifier
pair can use the same IR Code Group (the factory default A0).
4. While use of the 796-20 entails some added expense, it reduces programming time for both the hand-
held remotes and the keypads, in addition to providing additional convenience to the user.
5. The desired volume and other commands from the RC68+ Programmer (see Fig. 4) need to be
"taught" into learning remote controls (such as the Xantech URC types) and Smart Pads used in the
system, either directly or by using Dragon Drop IR™.
Connecting the REMOTE MASTER ON/OFF CONTROL Terminals
Asmentionedunder"PA1235PANELANDFEATUREDESCRIPTIONS", theREMOTEMASTERON/OFF
CONTROL terminals allow the power to the entire PA1235 to be turned ON and OFF by a remotely applied
DC Voltage. Figs. 9 and 11 are typical applications using this feature.
Using a DC Power Adapter as a Control Voltage
Fig. 10 illustrates how a PA1235 can be switched ON and OFF via the switched AC outlet on the rear of
a preamplifier or other control center.
• When the preamplifier Power Switch is switched ON, power is applied to the DC adapter which in turn
applies 5 V to 30 VDC to the PA1235, switching it ON.
• Similarly, when the preamplifier is switched OFF, the DC voltage to the PA1235 is removed, turning it
OFF.
®
12
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
• CAUTION: The output voltage of some adapters, such as the 781RG, drops off too slowly to provide
a quick turnoff for the PA1235. Therefore, when using any adapter (12 VDC max), always connect the
included 220 Ohm 1 Watt resistor in shunt with the REMOTE MASTER ON /OFF CONTROL terminals
as shown in Fig.9. Failure to do so may result in blowing of the power line fuse (item #10, Fig.3)
NOTE: Do not use the 220 Ohm resistor when connecting to the CO terminals of a ZPR68!
This must be the positive (+)
lead (white striped lead on
Xantech Power Supply Adapters).
COMMON BUS
COMMON BUS
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
2
3
CAUTION
Preamplifier, Control Center, etc.
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
RISK OF ELECTRIC
SHOCK. DO NOT OPEN
MODE
MODE
REMOTE MASTER
ON/OFF CONTROL
(+)
+
BRIDGED --
+
BRIDGED --
--
+
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
5-30 VOLTS DC
+
-- --
+
+
-- --
+
CAUTION:
You must use the included
220 Ω resistor. See
5V to 12 VDC Adapter,
such as a Xantech 781RG,
plugged into a Switched
AC Outlet on Preamplifier
CAUTION note above.
PA1235
(portion of rear panel)
Fig. 9 Using the REMOTE MASTER ON/OFF
CONTROL Terminals
A Multi-Zone Power Managed System, using a ZPR68, a GATEKEEP-IR™ and a PA1235
Fig. 11 shows a PA1235 in a typical multi-room system with a Xantech ZPR68-10 six-zone preamp and a
GATEKEEP-IR. The PA1235 has been designed specifically to work well with both Zone and All-Zone ON/
OFF management as rendered by the ZPR68-10.
In this example, the STATUS & GND output (0 to +12 VDC) of each zone of the ZPR68-10 is connected,
via a 2-conductor lead, to the CI & GROUND of each amplifier pair on the PA1235.
• This causes the ON/OFF condition of any given ZPR68-10 Zone to turn it's corresponding amplifier pair
ON/OFF (Standby ON/OFF).
Also, the common CO (control output, 0 to +12 VDC ) from the ZPR68-10 is used to drive the REMOTE
MASTER ON/OFF CONTROL terminals of the PA1235.
CAUTION: When making this connection, do not use the included 220 Ohm resistor! Refer also to
CAUTION notes, Fig. 9.
• When any one of the zones is turned ON, the common CO goes high (+12V), turning on power to the
entire PA1235.
• Similarly, when the last zone is turned OFF, the CO drops to 0 V, turning the PA1235 totally OFF.
NOTE: No IR control of the PA1235 is used in the system shown in Fig. 11. All volume, mute, etc. functions
are handled by IR control of the ZPR68-10. The PA1235 amplifier pairs are all set to the default volume
level setting by pressing the LEVEL (System) RESET button (refer to item #9, Fig. 3).
AC Power Management of the entire system as shown in Fig. 11 is accomplished, therefore, as follows:
a) The PA1235 is controlled via the STATUS and CO functions as noted above.
b) The Source Components are controlled via the GATEKEEP-IR™ sensor system and the IR macros in
the Smart Pads and, where used, IR macros in Learning Remotes (such as the Xantech URC types).
®
13
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
CONTROLLED SOURCE COMPONENTS
Cassette DecK
CD Changer
Satellite Receiver
AM/FM Tuner
L
R
L
R
V
L
R
L
R
286M Dual Blink-IR™
Mouse Emitters (2)
RCA type Patch Cords
IR Signal
To Video Distribution (if used)
RS41AV
1
2
3
4
RS41AV
Audio/Video
VIDEO
IR
REMOTE SWITCHER
Remote Switcher
CONFIRM
®
EMITTERS
SYLMAR, CA
•
MADE IN U.S.A.
AUDIO
LEFT
789-44
782
Type
CONNECTING BLOCK
®
AUDIO
RIGHT
POWER 15VAC
V
V
G
IR IN
Power
Supply
RS41AV
Power
Supply
INPUT
OUTPUT
IR
RCVR
12VDC
White
striped
side
To AC MAINS
(Unswitched)
To AC MAINS
(Unswitched)
6015900
3.5mm to-stripped-ends
mono cable (7)
PA1235 (rear panel)
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
COMMON BUS
®
SYLMAR, CA
LEFT
LOCAL RIGHT
1
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
3
LEFT
LOCAL RIGHT
4
LEFT
LOCAL RIGHT
LEFT
LOCAL RIGHT
COMMON AUDIO
BUS
AC 120V 60 HZ
4 AMP
2
5
6
FUSE
10 AMP
SLOW BLOW
CAUTION
WARNING
WARNING
WARNING
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
STEREO
MONO
BRIDGED
RISK OF ELECTRIC
SHOCK. DO NOT OPEN
MODE
MODE
MODE
MODE
MODE
MODE
TURN POWER
OFF BEFORE
CHANGING
MODES
TURN POWER
OFF BEFORE
CHANGING
MODES
TURN POWER
OFF BEFORE
CHANGING
MODES
LEFT
RIGHT
LEVEL
RESET
REMOTE MASTER
ON/OFF CONTROL
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
+
BRIDGED --
--
+
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
SPEAKER
LEFT RIGHT
5-30 VOLTS DC
AC LINE
ON/OFF
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
+
-- --
+
--
0
TO ROOM 1
SPEAKERS
TO ROOM 2
SPEAKERS
TO ROOM 3
SPEAKERS
TO ROOM 4
SPEAKERS
TO ROOM 5
SPEAKERS
TO ROOM 6
SPEAKERS
796-20
SYLMAR CA, MADE IN U.S.A.
SIX ZONE CONNECTING BLOCK / EXPANDER
ZONE EMITTERS
ZONE EMITTERS
ZONE IR INPUTS
ZONE 8 ZONE 7 COMMON
+12 IN +12 IN +12 OUT
ZONE IR INPUTS
ZONE 9
ZONE 6
ZONE 5
ZONE 4
+12 IN
G
G
G
G
+12 IN
G
+12 IN
G
+12 IN
G
ZONE 4
ZONE 5
ZONE 6
ZONE 7
ZONE 8
ZONE 9
A
B
A
B
A
B
A
B
A
B
A
B
GND
IR
To AC MAINS
(Unswitched)
+12 VDC
L
R
L
R
L
R
V
G
ST
IR
V
G
ST
IR
V
G
ST
IR
Smart
Pad3™
Smart
Pad3™
Smart
Pad3™
ROOM 5
ROOM 3
ROOM 1
L
R
L
R
L
R
V
G
ST
IR
V
G
ST
IR
V
G
ST
IR
780-80
780-80
780-80
"J" Box
IR Receiver
"J" Box
IR Receiver
"J" Box
IR Receiver
ROOM 2
ROOM 4
ROOM 6
Fig. 10 Basic PA1235/RS41/796-20 System - Uses Non-Dedicated Room Remotes
®
14
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
TROUBLE SHOOTING
If you encounter a problem, please review the items below. Be sure, in addition, to check other system
components, such as preamplifiers, CD players, speakers, speaker wiring, etc., that may be at fault.
1. Front Panel LEDs do not light – no sound.
• Check line cord for good contact in a live AC outlet.
• If the REMOTE MASTER ON/OFF CONTROL terminals (item #12, Fig. 3) are used, be sure applied
voltage is between +5 V and +30 VDC with proper polarity. Refer to Fig. 9.
2. Low level or no sound when operated without IR control.
• Level was previously set by IR to a low level or muted. Simply press LEVEL (System) RESET button
as instructed in item 9, Fig.3
3. 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 matching auto-formers and/or speakers as necessary to obtain higher impedance.
4. PA1235 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 (Out) position.
5. PA1235 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 the REMOTE MASTER ON/OFF CONTROL terminals are used, unplug for 15 seconds, then re-
plug.
6. Unit responds intermittently or not at all to IR commands.
• Look for IR noise at the IR receiver locations in the various rooms. Also, long lengths of shielded wire
from keypads or IR receivers can cause poor IR executions. Refer to the troubleshooting sections of
the IR receiver and keypad manuals you are using.
7. The PA1235 blew its fuse (item #10, Fig. 3) as power was turned OFF using an adapter driving
the REMOTE MASTER ON/OFF CONTROL terminals.
• The supplied 220 Ohm resistor may not have been connected in shunt with the REMOTE MASTER
ON/OFFCONTROLterminals. Besuretheresistorisconnectedandthattheleadsaremakingsecure
contact within the screw terminals of the connector. Refer to CAUTION notes, Fig. 9.
®
15
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
SPECIFICATIONS
Number of Channels .....................................................................................................................................................12
Power Output
Rated Continuous Power, Each Channel: ............................................. 8 Ohms .......................... 35 Watts
All 12 channels simultaneously driven,
20 Hz to 20 kHz, at rated THD.
Short Term Continuous, Each Channel: ................. 8 Ohms ............................................................ > 55 Watts
(2 channels driven, 1 kHz, at rated THD)
4 Ohms ............................................................ > 80 Watts
Bridged Power Output: .......................................... 8 Ohms .......................................................... > 150 Watts
(Short Term Continuous, one pair driven @ 1 kHz, at rated THD)
Rated THD ........................................................................................................................................................ < 0.08 %
Damping Factor (@ 50 Hz, 1/2 rated power) ....................................................................................................... > 100
S/N Ratio (A Weighted, Shorted Inputs, ref. to Rated Power) ....................................................................... > 100 dB
Frequency Response (@ 1 Watt, 3 dB) ............................................................................................ 12 Hz to 55 kHz
Input Sensitivity (@ Rated Power, stereo mode) ............... Input Gain (IR Controlled Setting)
Max. ......................................................................... 0.5 V
Default ...................................................................... 1.0 V
Min. ............................................................................. Off
Input Impedance ................................................................. LOCAL Inputs .................................................... 22 kOhms
COMMON AUDIO BUS Inputs .......................... 70 kOhms
Power Source ................................................................................. 120 VAC, 60 Hz (240 V Version: 240 VAC, 50 Hz)
Power Consumption ........................................................... No Signal ..................................... 30 Watts (0.25/0.13 A)
12 chan @ 1/10 rated power ......... 360 Watts (3.0/1.5 A)
12 chan @ rated power ................ 1090 Watts (9.1/4.6 A)
6 chan Bridged @ 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 @ +12 VDC)
Default IR Code Group (all amplifier pairs) ................................................................................................................ A0
Line Fuse Rating ......................... 120 V Version: 10 A Slow Blow 220 VAC. 240 V Version: 5 A Time-Lag 250 VAC)
Dimensions ............................................................................ 19" (483mm) W x 5-1/4" (133mm) H x 15.5" (394mm) D
Weight ................................................................................................................................................35.75 lbs (16.3kg)
3-9-01
Rev.C
®
16
PA1235
Download from Www.Somanuals.com. All Manuals Search And Download.
|