INSTALLATION INSTRUCTIONS
RAT1
REMOTE AUTO TRANSFORMER
The RAT1 is an infrared remote controlled stereo
RAT1
speaker volume control with impedance matching
capability. It allows individual volume control of from
one to 16 pair of stereo speakers from one stereo
power amplifier, using one RAT1 for each stereo
speaker pair. It is controlled with any Xantech IR
ReceiverorkeypadorwithXantechMIRV1motorized
volumecontrols. TheRAT1maintainscorrectimped-
ance matching between the amplifier and the speak-
ers with the use of instant setting S1 to S8 jumpers,
located on the unit. This eliminates the need for
separate impedance matching devices in multi-room
installations.
REMOTE AUTO TRANSFORMER
SPEAKER
OUTPUT
AMPLIFIER
INPUT
STATUS POWER
12VDC
L+ L– R– R+
L+ L– R– R+
Fig. 1 The RAT1
FEATURES AND SPECIFICATIONS
• 10-position relay driven stepped auto transformer design.
• Tri-Fi™ winding system for highest quality audio performance.
• Amplifier Input: 4-screw plug-in connector.
• Speaker Output: 4-screw plug-in connector.
• IR, STATUS & +12V: 4-screw plug-in connector.
• STATUS Input Jack: 2.1mm coaxial type.
• POWER Input Jack (+12V): 2.1mm coaxial type.
• Power Consumption: 300 mA @ +12V DC. Use Xantech Model 786-00 or 782-00 Power Supply.
• Requires IR commands from the RC68+ (or RC68) Programmer or from the MIRV1, for volume
operations.
• Using the RC68+ Programmer, internal E2 PROM can be set to different group codes for independent
operation of RAT1's when on a common IR bus.
• Factory preset Group Code number is 30.
• Independent grounds between channels.
• 75 watts per channel music power, 25 watts per channel continuous.
• Frequency response: 20 Hz - 20,000 Hz 1 dB at 1 Watt power input.
• Attenuation: 10 steps at 3 to 6 dB per step, 35 dB maximum.
• Impedance Multiplier Settings: S1, S2, S4, & S8.
• Plug-in connectors accept wire sizes from 24 to 12 gauge.
• "Flat Pack" design permits easy mounting.
• Dimensions: 8" x 4-1/8" x 2-5/8" (203mm x 105mm x 67mm).
1
SETTING THE IMPEDANCE MATCHING JUMPERS
The impedance matching jumpers are located under a clear mylar cover on the right side of the top of the
unit. Removethetwoscrewsforaccess. Theproperplacementofthesejumpersdependsonthenumber
of RAT1's and speakers used in the total installation. To set them for the best impedance matching
condition, refer to the following charts and procedures:
WHEN USING 8 OHM SPEAKERS
Number of Speaker Pairs Used
10 11 12 13 14 15 16
Min. Amp.
Impedance
1
2
3
4
5
6
7
8
9
S1 S1 S2 S2 S4 S4 S4 S4 S8 S8 S8 S8 S8 S8 S8 S8
S1 S2 S4 S4 S8 S8 S8 S8
4 Ohms
8 Ohms
WHEN USING 4 OHM SPEAKERS
Number of Speaker Pairs Used
Min. Amp.
Impedance
1
2
3
4
5
6
7
8
S1 S2 S4 S4 S8 S8 S8 S8
S2 S4 S8 S8
4 Ohms
8 Ohms
Procedure for all 4 Ohm or all 8 Ohm Speakers
1. Determine the rated speaker impedance (refer to the manufacturer's specifications - it must be the
same for all speakers used in the system).
2. Determine the total number of stereo speaker pairs used in the installation.
3. Determine the minimum safe amplifier operating load impedance (refer to the manufacturer's
specifications).
4. Find the correct jumper position from the above charts.
5. Place the jumpers in the same position on each RAT1 used in the system.
Example 1:
13 pairs of 8 Ohm wall speakers are to be used with 13 RAT1's in a 13 room system, all driven by one
amplifier rated for 4 Ohms minimum safe operating load impedance.
1. Refer to the chart "WHEN USING 8 OHM SPEAKERS".
2. Locate the number 13 in the top row.
3. On the next row, opposite "4 OHMS" and just below "13", note the letters "S8". These signify the
required impedance multiplier.
4. The two jumpers therefore, one for each channel, need to be plugged onto the S8 pins on each RAT1
that feeds each room.
Example 2:
3 pairs of 4 Ohm wall speakers are to be used with 3 RAT1's in a 3 room system, all driven by one amplifier
rated for 8 Ohms minimum safe operating load impedance.
1. Refer to the chart "WHEN USING 4 OHM SPEAKERS".
2. Locate the number 3 in the top row.
3. On the third row, opposite "8 OHMS" and just below "3", note the letters "S8". These signify the
required impedance multiplier.
4. The two jumpers therefore, one for each channel, need to be plugged onto the S8 pins on each RAT1
that feeds each room.
3
RAT1
Procedure for Speakers Other Than 4 or 8 Ohms
In this case, treat all speakers that are rated between 4 and 7 Ohms as 4 Ohm speakers, and use the charts
accordingly. Similiarly, all speakers that are rated 8 Ohms or higher, treat as 8 Ohms speakers. Again, all
speakers used in the system should be the same impedance (i.e. all 6 Ohms, all 7 Ohms, etc.).
Speaker Wire Recommendations
As a rule of thumb, use good quality 18 gauge speaker wire for runs up to 30', 16 gauge up to 70', and 14
gauge up to 150'. The 4-terminal connectors accept wire sizes up to 12 gauge max.
Procedure for Speakers of Differing Impedance Used in the Same System
You may run into installations where you need to combine speakers of different impedance in the same
system (8, 6, 4 Ohms, etc.). This is a more complicated situation that requires some calculation to obtain
optimum results. You need to find the paralleled impedance for each group of speakers with the same
impedance first and pick an "S" setting for each. Then check the overall paralleled "S" settings to see that
the impedance is higher than the minimum safe value specified for the amplifier.
Example 1:
2 pairs of 4 Ohm and 7 pairs of 8 Ohm wall speakers are to be used with 9 RAT1's in a 9 room system, all
driven by one amplifier rated for 4 Ohms minimum safe operating load impedance.
1. Calculate the total paralleled impedance of the 4 Ohm group first, by dividing 4 Ohms by 2.
4 ÷ 2 = 2 Ohms.
2. Multiply 2 by 4 (for the S4 setting) = 8 Ohms.
3. Calculate the total paralleled impedance of the 8 Ohm group next, by dividing 8 Ohms by 7.
8 ÷ 7 = 1.14 Ohms.
4. Multiply 1.14 by 8 (for the S8 setting) = 9.12 Ohms.
5. Next, calculate the overall paralleled impedance with the following formulae:
ZO = 1 ÷ [(1÷Z1) + (1÷Z2) + (1÷ZN...etc.)]
ZO = overall paralleled impedance
Z1 = 1st paralleled group after S setting
Z2 = 2nd paralleled group after S setting
ZN = additional paralleled groups, when used
Since only two paralleled groups are used in this example, the calculation is as follows:
ZO = 1 ÷ [(1÷8) + (1÷9.12)] = 4.26 Ohms.
Since this yields more than 4 Ohms, the S4 setting for the 4 Ohm group and the S8 setting for the
8 Ohm group are the correct ones to use.
Example 2:
2 pairs of 4 Ohm, 3 pairs of 6 Ohm and 7 pairs of 8 Ohm wall speakers are to be used with 12 RAT1's in
a 12 room system, all driven by one amplifier rated for 4 Ohms minimum safe operating load impedance.
1. Calculate the total paralleled impedance of the 4 Ohm group first, by dividing 4 Ohms by 2.
4 ÷ 2 = 2 Ohms.
2. Multiply 2 by 8 (for the S8 setting) = 16 Ohms.
3. Calculate the total paralleled impedance of the 6 Ohm group next, by dividing 6 Ohms by 3.
6 ÷ 3 = 2 Ohms.
4. Multiply 2 by 8 (for the S8 setting) = 16 Ohms.
5. Calculate the total paralleled impedance of the 8 Ohm group next, by dividing 8 Ohms by 7.
8 ÷ 7 = 1.14 Ohms.
4
RAT1
6. Multiply 1.14 by 8 (for the S8 setting) = 9.12 Ohms.
7. Next, calculate the overall paralleled impedance ZO. Since three paralleled groups are used in this
example, the calculation is as follows:
ZO = 1 ÷ [(1÷16) + (1÷16) + (1÷9.12)] = 4.26 Ohms.
Since this yields more than 4 Ohms, the S8 setting for the 4 Ohm group, the S8 setting for the 6
Ohm group and the S8 setting for the 8 Ohm group are the correct ones to use.
Impedance Setting Tips
1. You may use the above method to calculate the correct impedance matching condition for practically
any combination of speakers and RAT1s.
2. Use the lowest "S" setting possible consistent with the requirement to keep above the minimum safe
operating load impedance for the amplifier. You may have to try 2 or 3 values of "S" for each
impedance group and recalculate the overall paralleled impedance ZO each time, before you arrive
at the final correct value.
3. When you test the system, you may find volume differences between the impedance groups when all
RAT1s are set to max. volume. This is normal and is usually not a problem, since the user will be
listening at lower levels most of the time. If you feel it necessary to even out the volume levels, move
the "S" jumpers to the next higher number on the RAT1s that feed the loudest group.
NOTE: While speakers of differing impedance can be accommodated using these procedures, it is
highly recommended you not do so on a regular basis. The easiest and best performing installation
is achieved by using speakers of the same impedance throughout the entire system. Then use the
charts to determine the correct jumper "S" settings.
INSTALLATION – COMMON IR BUS SYSTEM
Fig. 3 illustrates a typical installation using three RAT1's along with other Xantech products in a 4-room
multi-room system. The principles shown should be used as a guide when planning your own specific
installations. It is configured as follows:
1. For simplicity, only three RAT1's are shown. Larger systems (up to a max. of 16 using 8-Ohm
speakers) may be used. 16 is the maximum number using 8-Ohm speakers and an amplifier with a
minimum loading impedance of 4 Ohms. See chart, in: Setting the Impedance Matching Jumpers
section).
2. Note that a Common IR Bus connects the 780-80 "J" Box IR Receiver, the two MIRV1 Volume
Controls, a 480-00 "Dinky Link" IR Receiver and a Smart Pad3 keypad to each of the RAT1's. In
addition, it connects to a 789-44 Connecting Block, so that the source equipment can be controlled
from the remote rooms.
3. Since a common IR bus is used, each of the RAT1's and its connected MIRV1 (where used) must use
adifferentIRCodeGroupnumber, sothatthevolumelevelineachroomcanbeadjustedindependent
of the others.
To make code group changes, refer to the RC68+ Programmer Instructions.
NOTE: When shipped from the factory, the RAT1 and MIRV1 are set to code group number 30.
If you use group 30 or change to a different number, be sure to always set the RC68+ to the
same number.
4. When a code group is chosen, "teach" volume commands from the RC68+ Programmer (see Fig. 2)
into learning remote controls (and the keypad), dedicated to each room. You may use the Xantech
URC learning remote controllers for this purpose.
NOTE: With a Common IR Bus system, you cannot carry the same remote control from room-
to-room. You must use a dedicated remote for each room into which you have "taught" the
specific RC68+ Code Group that operates the specific RAT1 that controls the volume for that
room!
5
RAT1
If you wish to carry remotes that have the same codes from room-to-room, use a Dedicated IR Bus
System as shown in Fig. 4.
5. A 490-30 "Micro Link" IR Receiver plugs into the 789-44 for local control of the source equipment (i.e.
equipment behind closed doors, etc.).
6. A "STATUS" system is included. This permits the power "ON/OFF" status of the A/V receiver or
amplifier system to be visible in each of the remote rooms. It also permits the power management
capability of the Smart Pad3 to operate.
7. The "STATUS" indicator LEDs on the 780-80 "J" Box IR Receiver, the two MIRV1 Volume Controls
and the Smart Pad3, are powered by a 786-00 Power Supply plugged into a "SWITCHED" AC outlet
on the A/V receiver or amplifier system. When the switched outlet is "ON", +12 Volts from the
786-00 passes through one of the 4 bus-conductors (STATUS line) to the LED indicators.
NOTE: A resistor can be placed in series with the STATUS terminal at each IR receiver (IR receivers
only, if so equipped) for adjustment of the brightness of the Status LED. See the specific installation
instructions for the IR receiver for details.
NOTE: When connecting system devices, be sure to carefully match up the terminals according to
their markings as follows:
IR IN (IR), STATUS (ST), GND (G) and +12VDC (V).
Power Supply Considerations
Up to 3 RAT1's plus associated MIRV1's and IR components can be used with one 782-00 Power Supply.
(e.g. 9 RAT1's with associated components would require 3 of the 782-00 Power Supplies). Typical power
supply connections are shown in Figs. 3, 4 and 6.
6
RAT1
MAIN ROOM, EQUIPMENT AREA, ETC.
786-00 "STATUS" power supply. Plug into a SWITCHED
CONTROLLED COMPONENTS
490-30
"Micro Link"
IR Receiver
AC Outlet on A/V Receiver (see text).
Satellite Receiver
(i.e. cabinet mounted for
IR control in main room)
CAUTION: Stereo receivers usually have two sets of speaker terminals, "A"
and "B". Be sure all speakers connected to both "A" and "B" are taken into
consideration when paralleling speakers, so that the amplifiers are not loaded
by an impedance that is lower than that specified by the manufacturer.
283M Blink-IR™
SPEAKER TERMINALS
A/V RECEIVER,
L
R
+
-
-
+
AMPLIFIER, ETC.
CD Changer
(Back Panel)
789-44
Connecting Block
782-00
Power Supply
283M Blink-IR™
(Place on FRONT
Panel IR Sensor)
+12 VDC
283M Blink-IR™
GND
STATUS
IR IN
Mouse Emitter
To 120 V AC
(unswitched)
RAT1 #1
RAT1
RAT1 #2
REMOTE AUTO TRANSFORMER
RT1
REOTE AUTO TRANSFORMER
SPEAKER
OUTPUT
AMPLIFIER
INPUT
TATUS POWER
12VDC
L+ L– R– R+
L+L– R– R+
RAT1 #3
RAT1
REMOTE AUTO TRANSFORMER
SPEAKER
OUTPUT
AMPLIFIER
INPUT
STATUS POWER
12VDC
L+ L– R– R+
L+L– R– R+
SPEAKER
OUTPUT
AMPLIFIER
INPUT
STATUS POWER
12VDC
L+ L– R– R+
L+L– R– R+
R
R
R
L
L
L
+
–
–
+
+
–
–
+
+
–
–
+
IR
V
ST G
XANTECH
IR
V
ST
480-00
"Dinky Link"
IR Receiver
G
IR ST
G
V
S-62/64/66
780-80
"J" Box
IR Receiver
MIRV1
MIRV1
Wall Speakers
Smart
Pad3™
Volume
Control
Volume
Control
ROOM 2
ROOM 3
ROOM 4
Fig. 3 A RAT1 System Using a Common IR Bus
7
RAT1
INSTALLATION – DEDICATED IR BUS SYSTEM
Fig. 4 illustrates an installation where each remote room has a Dedicated IR Bus going to the RAT1 that
controls it. The IR bus is not connected in common as it is in Fig. 3. This eliminates the need for dedicated
remotes, allowing you to carry the same remote(s) from room-to-room. It is configured as follows:
1. Again, forsimplicity, onlythreeRAT1'sareshown. Largersystemsmaybeconfigured, usingthesame
connectiontechniques(uptoamax.of16RAT1's). 16isthemaximumnumberusing8-Ohmspeakers
and an amplifier with a minimum loading impedance of 4 Ohms. See chart on page 3.
2. Each Dedicated IR Bus connects the 780-80 "J" Box IR Receiver, the two MIRV1 Volume Controls,
a 480-00 "Dinky Link" IR Receiver and a Smart Pad3 keypad to their respective RAT1's.
3. In order to control the common source components in a Dedicated IR Bus system, it is necessary to
use a 793-00 Serial Control Combiner, connected as shown in Figs. 4 & 5. The 793 provides diode
isolation between the IR signal lines but allows common operation of the source equipment through
the 789-44 Connecting Block, as shown.
Set the LOGIC POLARITY SELECTOR DIP switches on the 793 for "active high" operation - that is
- all even numbered switches to "ON" - all odd numbered switches to "OFF".
4. The input and output ports on the 793 are 3.5mm mono mini jacks. Use matching mini plug cables
with stripped ends when connecting. Polarity must be observed as shown in Fig. 5.
For systems using more than five RAT1's, you will need additional 793-00's. These can be easily
"daisy chained" as shown in Fig. 5.
5. SinceaDedicatedIRBussystemisused,eachoftheRAT1's(andMIRV1's)canoperatewiththesame
IR Code Group number. In this case, the Code Group number, as received from the factory, should
be used.
NOTE: When shipped from the factory, the RAT1 (and MIRV1's) are set to Code Group number
30. Be sure to set the RC68+ to the same number!
If a particular system requires a code group number change, refer to the RC68+ Programmer
Instructions for code group setting procedures.
6. The desired volume commands from the RC68+ Programmer (see Fig. 2) need to be "taught" into
learning remote controls and keypads used in the system. You may use the Xantech URC learning
remote controllers for this purpose.
7. A 490-30 "Micro Link" IR Receiver plugs into the 789-44 for local control of the source equipment.
8. As in Fig. 3, a "STATUS" system is included.
NOTE:Whenconnectingsystemdevices,besuretocarefullymatchuptheterminalsaccordingtotheir
markings as follows:
IR IN (IR), STATUS (ST), GND (G) and +12VDC (V).
Daisy-Chaining 793-00 Serial Control Combiners for Control of Common Components
Fig.5 illustrateshowtwo793-00SerialControlCombinersare"Daisy-Chained"toaccommodateadditional
RAT's in a dedicated IR Bus System. This process can be repeated as necessary to accommodate the
number of RAT's needed in the system. Simply connect the "B" CONTROL OUTPUTS port of the next 793
into the "A" CONTROL OUTPUTS port on the preceding 793 with a 3.5-to-3.5mm mono-mini cable as
shown.
NOTE: Be sure that all ten LOGIC POLARITY SELECTOR DIP switches on each 793 are set correctly. In
this case, set them for "active high" operation - that is - all even numbered switches to "ON" - all odd
numbered switches to "OFF".
8
RAT1
MAIN ROOM, EQUIPMENT AREA, ETC.
490-30
"Micro Link"
IR Receiver
CONTROLLED
COMPONENTS
786-00 "STATUS" power supply. Plug into a SWITCHED
AC Outlet on A/V Receiver (see text).
(i.e. cabinet mounted
for IR control
Satellite Receiver
CAUTION: Stereo receivers usually have two sets of speaker terminals, "A"
793-10
and "B". Be sure all speakers connected to both "A" and "B" are taken into
consideration when paralleling speakers, so that the amplifiers are not loaded
by an impedance that is lower than that specified by the manufacturer.
Serial Combiner
in main room)
SPEAKER TERMINALS
283-00 Emitter
A/V RECEIVER,
AMPLIFIER, ETC.
(Back Panel)
L
R
+
-
-
+
CD Changer
789-44
Connecting Block
283M Blink-IR™
(Place on FRONT
Panel IR Sensor)
+12 VDC
283M Blink-IR™
GND
782-00
Mouse Emitter
STATUS
IR IN
Power Supply
To 120 V AC
(unswitched)
RAT1 #1
RAT1 #2
E AUTO TRANSFORMER
RT1
REOTE AUTO TRANSFORMER
SPEAKER
OUTPUT
AMPLIFIER
INPUT
POWER
12VDC
L+ L– R– R+
L+L– R– R+
RAT1 #3
RAT1
REMOTE AUTO TRANSFORMER
SPEAKER
OUTPUT
AMPLIFIER
INPUT
STATUS POWER
12VDC
L+ L– R– R+
L+L– R– R+
SPEAKER
OUTPUT
AMPLIFIER
INPUT
STATUS POWER
12VDC
L+ L– R– R+
L+L– R– R+
R
R
R
L
L
L
+
–
–
+
+
–
–
+
+
–
–
+
IR
V
ST G
XANTECH
IR
V
ST
G
480-00
"Dinky Link"
IR Receiver
IR
ST
G
V
S-62/64/66
780-80
MIRV1
MIRV1
Wall Speakers
Smart
Pad3™
"J" Box
Volume
Control
Volume
Control
IR Receiver
ROOM 2
ROOM 3
ROOM 4
Fig. 4 A RAT1 Dedicated IR Bus System
9
RAT1
INSTALLATION (cont'd)
CONTROLLED
COMPONENTS
793-10
793-10
Serial Combiner
Serial Combiner
Satellite Receiver
283M
Blink-IR™
CD Changer
789-44
Connecting Block
283M Blink-IR™
Mouse Emitter
+12 VDC
GND
–
+
STATUS
IR IN
To additional
Emitters if
needed
"Daisy-Chain"
connection. Use
3.5/3.5mm Mini-
Plug cable,
Use Mini-Plug-
to-Stripped
White
Stripped
Side (+)
To IR IN
To IR IN
and GND
on each RAT1
and GND
end cables,
on each RAT1
Pt. # 6017400
Pt. # 6015900
Fig. 5 Daisy-Chaining 793-00's in Multiple RAT1 Dedicated IR Bus Systems
Driving Multiple Speakers From a Single RAT1
In some cases you may need to
drive more than one set of speakers
from a single RAT1, such as in large
rooms or adjoining areas where
common volume operation is
acceptable. A typical system is
shown in Fig. 6.
RAT1
REMOTE AUTO TRANSFORMER
FROM AMPLIFIER
SPEAKER TERMINALS
SPEAKER
OUTPUT
AMPLIFIER
INPUT
STATUS POWER
12VDC
L+ L– R– R+
L+L– R– R+
1. Use the same charts and rules for
setting the impedance jumpers.
In Fig. 6, all 8-Ohm speakers and
an amplifier capable of handling
an impedance of 4-Ohms, is
assumed; resulting in a jumper
setting of S1.
782-00
Power Supply
To 120 VAC
(unswitched)
786-00
Status Power
Supply
R
R
L
L
+
–
–
+
+
–
–
+
IR
V
ST
G
2. Note that two MIRV1's are used;
one at one location in the room
and the 2nd in another, for
convenience of use. They both
controlthesamevolumeleveland
track each other.
IR
V
ST
G
MIRV1
780-80
MIRV1
"J" Box
IR Receiver
Volume
Control
Volume
Control
LARGE ROOM OR AREA
Fig. 6 Driving Two Speaker Pairs From One RAT1
12-8-00
Rev.C
10
RAT1
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