Univox PLS-X1 User manual

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Univox® PLS-X1, X3, X5
Induction Loop Drivers
Installation Guide
Univox® PLS-X1 Part No 217100
Univox® PLS-X3 Part No 217300
Univox® PLS-X5 Part No 217500

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Content
Introduction..................................................................................................................... 4
Package contents........................................................................................................... 4
Connections and controls............................................................................................. 5
1. Input level control ............................................................................................. 6
2. Input level LEDs................................................................................................... 6
3-4. Parametric MLC ............................................................................................... 6
5. System Diagnostics ............................................................................................ 7
6. Loop Current Control.......................................................................................... 7
7. Loop Current LEDs .............................................................................................. 7
8. Voltage Clipping/Peak LED................................................................................ 8
9. Loop Monitor/Headphones Socket.................................................................. 8
10. Power LED.......................................................................................................... 8
11. Loop Terminals.................................................................................................. 9
12. DC Supply socket.............................................................................................. 9
13. Monitor Speaker Connector (screw 1+2).................................................... 9
14. Auxiliary DC Power Output (screw 3) ........................................................... 9
15. Remote Input Monitor Connector (screw 4+5).......................................... 9
16. Remote Output Monitor Connector (screw 5+6).....................................10
17. Monitor Volume Control ................................................................................10
18. Input Power Amplifier (In Pow Amp)..........................................................10
19. Output Pre-amplifier (Out Pre Amp)...........................................................10
20. Input 3 ..............................................................................................................11
21. Input 2 ..............................................................................................................11
22. Speech Enhancement (Flat/Speech) DIP Switch 1.................................11
23. 50-100 V/Line DIP Switch 2 + 3..................................................................11
24. Override On/Off DIP Switch 4 .......................................................................12
25. Input 1 ..............................................................................................................12
26. Speech Enhancement (Flat/Speech) DIP Switch 1.................................12
27. Line/Mic DIP Switch 2 + 3.............................................................................13
28. Phantom Power/DIP Switch 4......................................................................13

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Prepare installation .....................................................................................................14
Planning...................................................................................................................14
Tools required.........................................................................................................14
Loop cable ..............................................................................................................14
Placement of the driver .......................................................................................15
Placement of the microphones..........................................................................15
Maximum recommended segment size (to comply with IEC 60118-4) ...15
Installation.....................................................................................................................16
Start-up procedure ......................................................................................................16
Input connection and adjustments..........................................................................16
Output connection and adjustments .......................................................................17
Metal Loss Correction frequency setting ................................................................18
MLC function in maximum position..........................................................................18
Commissioning and certification...............................................................................18
Default Settings............................................................................................................19
Rear panel...............................................................................................................19
Front panel..............................................................................................................19
Trouble shooting...........................................................................................................20
Technical Specification ...............................................................................................22
Audio Input 1..........................................................................................................22
Audio Input 2 .........................................................................................................22
Input 3 .....................................................................................................................22
In Pow Amp ............................................................................................................23
Out Pre Amp ...........................................................................................................23
Loop output ...........................................................................................................23
Supplementary Outputs.......................................................................................23
Safety..............................................................................................................................24
Warranty.........................................................................................................................24
Maintenance and care.................................................................................................25
Service ............................................................................................................................25
Technical data...............................................................................................................25
Environment..................................................................................................................25
Measuring devices .......................................................................................................26
Notes ..............................................................................................................................27
The Installation Guide is based on the information available at the time
of printing and are subject to change without notice.

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Introduction
Thank you for choosing Univox.
The new Univox®PLS-X series loop drivers combine 50 years of experience with the latest
in electronic design to deliver unrivaled sound clarity, power and performance in a compact
stylish housing.
Our Engineering Simplicity philosophy is evident in the functionality and user-friendliness for
each model.
The three models in the series, PLS-X1, PLS-X3 and PLS-X5 are identical with the exception
of output power. Each model offers three inputs, two programmable, including a 100V line
setting, a self-test mode, loop- and speaker amplifier monitor. With LED indicators for input
and output levels, optimizing system performance is simple.
The PLS-X Series is integrated into Univox®Loop Designer, a free, web-based project planning
and design soware, enabling fast and accurate configuration of induction loop systems.
Please read this user guide carefully before installation and usage of this product. All Univox®
loop drivers have a very high output power resulting in products capable of fulfilling standards.
Package contents
The PLS-X series package contains the following components:
• Loop driver
• DC Power Supply
• Power cable
• Three phoenix screw terminals
• Four rubber feet
• T Sign
• Rack mounting plate with 8 screws
• Measuring protocol/certificate
• Installation Guide

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Connections and controls
PLS-X5
Loop current
Monitor
-6
Parametric MLC
In 1 In 2 In 3
Professional Loop System
0 +12 dB Clip
System Diagnostics
-18 On
0 3 6 9 dB
100 500 1k 2k
Off
1. 1. 1.
2. 4. 5. 7.
6.
8. 9. 10.
1. Input level control (Input 1-3)
2. Input level LEDs
3. Parametric MLC control
4. Parametric MLC knee point switch
5. System diagnostics switch and LED
6. Loop current control
7. Loop current LEDs
8. Voltage clipping/Peak LED
9. Loop monitor jack
10. Power LED
11. Loop terminals
12. DC supply jack
13. Monitor speaker connector (screw 1+2)
14. Auxiliary DC power output (screw 3)
15. Remote input monitor connector (screw 4+5)
16. Remote output monitor connector (screw 5+6)
17. Monitor volume control
18. Direct connection to loop power amplifier
(In Pow Amp)
19. Pre-amplifier output (Out Pre Amp)
20. Input 3 (Phoenix screw terminal/RCA)
21. Input 2 (Phoenix screw terminal)
22. Speech enhancement DIP switch
(Flat/Speech)
23. 50-100 V line DIP switch On/Off
24. Override DIP switch On/Off (Input 3)
25. Input 1 (Balanced XLR)
26. Speech enhancement DIP switch
(Flat/Speech)
27. Line/Mic sensitivity DIP switch
28. Phantom power On/Off
DC+
In Pow
Amp
Input 2 Input 1
LR + -
L
R
www.univox.eu
Flat / Speech
Override / OFF Flat / Speech Phantom / OFF
Monitor
Out Pre
Amp
+
PUSH

+
50-100 V / OFF
Line / Mic
Input 3
-+
C
12.
11. 17.
13.
14.
15.
16.
18.
19.
20.
21.
28.
27.
26.
24.
23.
22.
25.
3

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Explanation
Note
Univox PLS-X series is operational only if a loop cable is connected to the driver. Otherwise,
the Peak indicator is lit constantly as a warning.
All controls are regulated with a small screwdriver.
1. Input level control (In1-In3)
Each input can be set to correct input by appropriate single-turn potentiometer located on
the front panel.
2. Input level LEDs
The thee blue and single red LEDs indicate the signal level at the output of the pre-
amplifier.
To ensure the AGC function is optimised, the signal level should be set to 0dB with
maximum peaks reaching +12dB, i.e. the 0dB LED should be lit most of the time during the
audio programme and the +12dB indicator should flicker occasionally.
3-4. Parametric MLC
The parametric metal loss control function enables system frequency response correction
in cases where the signal strength is strongly influenced by the surrounding metal. By
selecting an appropriate parametric curve, the installer can fine tune the frequency
response, compensating for the effects of different metal types and configurations.
Four options for parametric compensation can be selected: 2kHz, 1kHz, 500Hz and 100Hz.
The chosen curve sets the frequency at which the metal loss control starts to compensate.
The function is powerful, however, excessive compensation can lead to signal limiting in
the treble range. If signal limiting occurs, the red Peak LED (8) will illuminate indicating
that the signal is limited, i.e. the available voltage in the driver is insufficient to deliver a
constant current (voltage clipping).

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5. System diagnostics
Univox PLS-X series has a built-in system test. We recommend that this feature is used
periodically, at least monthly, to check the integrity of the loop driver, its inputs and the
loop condition.
To access the system diagnostics mode, set the switch on the front panel to the right.
All the inputs are now disabled and an internal 1kHz oscillator is connected to the input
instead. The oscillator pulses at 2 seconds intervals with a 0dB level, activating the AGC
regardless of the adjusted sensitivity. The red LED indicator is flashing with the signal.
If the input level LEDs and at least one output loop current LED flash in unison, the system
is working correctly.
If the input and output LEDs do not flash, check that the loop is connected and not open circuit.
Also check the proper connection of the signal source.
If only the input LEDs flash, and the loop is properly connected, the output current is set
too low. Increase the output current.
6. Loop current control
The loop current can be adjusted by turning the loop current control (6) potentiometer.
7. Loop current LEDs
The current output level is indicated by the loop current LEDs in 3dB increments. The LED
dB scale is relative to the loop output current and is based on the available current of
the particular model. 0dB is lit when the output current is 1/4 of the maximum available
current and the power is 1/8 of the available power. Each 3dB increment represents a
doubling of the output. However, the only way to set the output level to the correct IEC
level is to use a professional field strength meter, preferably Univox FSM 2.0.

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8. Voltage clipping/Peak LED
The Peak LED will illuminate when the voltage is clipping, i.e. there is insufficient voltage to
maintain a constant current.
Momentary short term voltage clipping is unlikely to be audible in hearing aids, but if
clipping occurs for any length of time (the Clip LED (8) remains on), the audio quality will
suffer and remedial action should be taken to reduce or eliminate the problem.
Voltage clipping will occur at higher frequencies first. It causes distortion of the audio
signal. Situations that require higher voltages from the loop driver and where voltage
clipping may occur are typically where:
• The loop has a high impedance. The impedance of the cable is determined by its length
and cross sectional area. The longer and thinner the cable, the higher its impedance.
The feed cable must also be considered when calculating the loop impedance. A 2-turn
loop will have an impedance more than double that of a single turn loop of the same
length and cross-section due to mutual inductance.
• Strong compensation from the parametric MLC control is applied
Note
In some cases metal reinforcement can actually reduce the voltage requirement.
9. Loop monitor/headphones socket
Univox®PLS-X series has a powerful speaker amplifier and a 3.5mm headphone socket
built-in. The headphone socket is on the front panel, the speaker connectors (13) and
volume control (17) are placed in the rear panel. Both are fed directly from the loop
providing an accurate reproduction of the loop signal. A distorted, poor quality signal or
lack of audio input is easily identified by use of this feature.
Note 1
The volume control is located in the rear panel and controls the volume level of both the
external speaker, if attached, and the headphones output.
Note 2
Excessive output to speaker may reduce the overall loop output power.
10. Power LED (On)
The blue Power LED is illuminated at all times when the unit is connected to a working
power supply.

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The units are designed to run 24/7. They do not have a separate on/off switch and can only
be turned off by disconnecting or turning off the power supply.
11. Loop terminals
The two outer terminals (screw 1 and 4) are used for connecting a single turn loop. The
two inner centre terminals (screw 2 and 3) provide a shorting bar to couple a 2-turn loop
when a twin core cable is used (see page 14).
12. DC Supply socket
The external DC power supply provided with the loop driver is connected at the DC supply
socket in the rear panel.
Note
Connect the power cord to the amplifier first, before connecting to the wall socket to avoid
high inrush current.
The voltage rating of the supply is dependent on the model.
Only Univox approved power supplies correctly rated for the loop driver model should be
used. The use of incorrectly rated, or third party power supplies will invalidate your 5 year
warranty.
13. Monitor speaker connector (screw 1+2)
A monitor speaker may be permanently connected providing some sound reinforcement in
smaller rooms. In this case, care needs to be taken to avoid acoustic feedback.
14. Auxiliary DC power output (screw3)
The DC output is available to power compatible accessories. The output voltage is
dependent on the loop driver model/external power supply.
15. Remote input monitor connector (screw 4+5)
A LED connected to this terminal will mirror the operation of the -6 dB input Level LED on
the front panel, thus allowing the monitoring of the presence of an input signal in a more
convenient location.

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16. Remote output monitor connector (screw 5+6)
A LED connected to this terminal will mirror the operation of the 0dB output current Level
LED on the front panel, thus allowing the monitoring of the presence of output current in a
more convenient location.
17. Monitor volume control
Controls the volume for the headphone output and the external speaker where fitted.
See (9) Loop Monitor and (13) Monitor Speaker Connector.
18. Direct connection to loop power amplifier (In Pow Amp)
An external signal source can be connected to the input and directly drive the loop
amplifier's power amplifier without effecting the amplifier's filter and AGC functions.
Typical connection: External DSP for direct control of frequency distribution and dynamic.
Input sensitivity: 0dBu (0.775V/10kOhm).
Note 1
The loop amplifier's other inputs (In1-In3) can be used simultaneously.
Note 2
This input lacks the 5kHz lowpass filter and is unballaned. Input impedance: 10kOhm
19. Pre-amplifier output (Out Pre Amp)
This output delivers an output signal aer adjustment of input level, filter and AGC fun-
ctions.
Typical connections:
• Connection to recording devices with the built-in AGC function as level control
• Connection to a PA system (for example a mixer)
• Output signal to another loop amplifier through its RCA input (see 20)
Note
Connection of several loop amplifiers from one signal source is most easily done by con-
necting the signal in parallel to the balanced input (In1 or In2) of each amplifier. Each
amplifier is then individually adjusted with MLC and frequency adjustment.
Output level: approx. 0.5V.