AUDIOropa A-4264-0 Pro Loop DCC Plus Instruction Manual

: June 6, 2024
: AUDIOropa

Table of Contents

AUDIOropa A-4264-0 Pro Loop DCC Plus
Overview of the connections and operating elements
What’s in the box
Important Information
Installation
Warranty
PRO LOOP DCCplus specifications
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

AUDIOropa A-4264-0 Pro Loop DCC Plus

We would like to congratulate you on purchasing your new PRO LOOP DCCplus induction loop amplifier. You have chosen a product that skillfully combines appealing design with high technical performance.
This handbook describes exactly how the amplifier works and how it is to be used. Please read through the operating instructions carefully before using the amplifier. We also reserve the right to make changes to incor-porate new product developments at any time.

Overview of the connections and operating elements

Front panel

Level indicator for AGC/compression
Level indicator for induction loop current
Power supply indicator
Left bore for control cover
Input sensitivity control
Metal loss compensation control
Indicator “OVERLOAD”
Indicator for excessive heat “OVER HEAT”
Indicator “LOOP ERROR”
Loop current control
Right bore for control cover
Earphone jack
ON/OFF Switch
Rear panel
Voltage selector
Power jack (115/230V / 50/60Hz)
Fan outlet
Screw terminal for loop connection
Priority input
Slave connection sockets
Audio inputs

Description of the indicators, controls and connectors at the front panel

Level indicator for AGC/compression: The six LEDs indicate the level of compression of the input signal.
Level indicator for induction loop power: This shows the electrical current within the loop.
Power supply indicator: The green LED is lit if the induction loop amplifier is switched on and the self-test procedure was successful.
Left bore for control cover: It is possible to secure the control settings against accidental readjustments by mounting the control cover here with the supplied screws.
Input sensitivity control: Sets the input sensitivity of input IN1 and input IN2.
Metal loss compensation control: Adjusts the compensation for metal loss.
Indicator “OVERLOAD”: The yellow LED lights up when an excessive current is registered within the loop or if the output signal gets overloaded. If this LED is lit, decrease the output current. A short flicker at volume bursts is normal and does not indicate a problem.
Indicator for excessive heat “OVERHEAT”: The red LED lights up if excessive temperature is measured within the amplifier, the amplifier switches off for reasons of safety. After cooling off, the amplifier switches on again automatically.
Indicator “LOOP ERROR”: The red LED is lit when a faulty loop is detected. In case of the loop resistance being to low, please refer to section “Cable cross section and wire diameter“ on page 18 and increase the resistance.
Loop current control: This control sets the maximum electrical current of the induction loop.
Right bore for control cover: It is possible to secure the control settings against accidental readjustments by mounting the control cover here with the supplied screws.
Earphone jack: You can connect headphones to the amplifier.
ON/OFF Switch: The loop amplifier is switched on and off with this switch.
Description of the indicators, controls and connectors at the rear panel
Voltage selector: Select the voltage according to your electrical mains power.
Power jack (115/230 V / 50/60 Hz): Connection for mains power supply.
Fan outlet: Please do not cover it so that any heat generated within the device can be dissipated.
Screw terminal for loop connection: The both ends of the loop cable will be connected here.
Priority input: Connection for systems which can override the audio signal on the induction loop. For example a alarm system or a PA-system.
Slave connection sockets: Connect master and slave amplifiers to this amplifier.
Audio inputs: Connection for external audio sources.

What’s in the box

Please make sure that all the following parts are in the box:

PROLOOP DCCplus induction loop amplifier
Power cord
Control cover incl. screws
Induction Listening” sticker
Operating instructions
Warranty card

If anything is missing, please contact your retailer or the manufacturer.

General information
The PROLOOP DCCplus amplifier has been designed for use in professional venues where high reliability and safe operation are essential. The 100% short- circuit-proof amplifier with its extremely stable output power meets these requirements.

How it works
The induction loop amplifier generates an alternating electromagnetic field around the loop cable. The loop con-sists of an insulated wire, which is usually laid singly (or doubly) along the side of the room. When the hearing aid user sets the hearing aid to the “T position”, voltage is induced within the T coil. This voltage depends on the amplifier’s input signal. Now the signals are amplified by the hearing aid and converted into sound. The alterna-ting electromagnetic field inside the loop allows the hearing aid user to move around freely within the room and to receive the voice- or music signals as pleasant high-quality sound, free of environmental noise.

Notes on safe operation
This device complies with all the necessary EU directives and bears the CE seal of approval. To make sure that your device enjoys a long service life, please observe the following information.

Important Information

To prevent accidents or personal injury caused by electrical shocks, never place any type of container filled with a liquid, such as a vase, on the device.
Never pull on the power cord to remove the plug from the wall outlet; always grasp the plug directly and pull it out.
Do not operate the device near heat sources or in rooms with high humidity (operating temperature range 0-40°C).
Do not cover the air vents so that any heat generated by the device can be dissipated by air circulation.
Depending on how it is used, the device can develop high temperatures in the heat sink and at the air vents. Be careful not to touch these elements by accident – risk of burns !!!
Do not use the device:
- if the power cord or the plug are defective or damaged.
- if the device is not functioning properly or is defective.
- if the device has been dropped or damaged in any other way.
To clean the device, simply wipe it with a soft, dry cloth – never use any kinds of chemicals or water. Should a repair become necessary, have this done by an authorized technician only.

Installation

This device operates with a dangerous voltage of 115 V or 230 V. Never attempt to open the de- vice yourself and never insert anything into the air vents! You could receive a severe electrical shock!

Important notes

When installing the induction loop amplifier, make sure that the air intake at the top and the air outlet at the back are not covered or blocked in any way.
It is normal for the amplifier to become warm when in operation. It is important that air is able to circulate freely around the device. If the air circulation is impeded in any way, the device will require forced cooling.
Make sure that the amplifier is mounted securely and will not slip or fall.
To prevent any damage to the internal components, you should not screw screws or drill holes in the device enclosure.
Make sure that the voltage indicated on the rear side of the device is the same as your local voltage.
All connections should be made by a qualified technician only and only when the device is switched off.

Tips

Before beginning to install the device, you should be sure to check the area for any magnetic interference. Such interference can have a negative affect on the operation of the device or make it impossible altogether. Interference can be caused by transformers, power lines, rein- forced concrete or floor heating systems.
If the loop is to be installed in a pipe, then make sure that the pipe is made of plastic.
Do not lay any input signal cables parallel to the loop wire.
Avoid using dynamic microphones inside the loop. Always chose symmetrical electret or capa- citor microphones to prevent acoustic feedback.
If it is not possible to lay the loop in a circle or in a “figure 8” (double circle), then a special loop design calculated by an experienced technician will be necessary. (Please do not lay any comb or meander structures!)

Cable cross section and wire diameter
The best audio quality can be reached if the DC (direct current) resistance of the induction loop is between 0.5 and 3 Ohm. The DC resistance depends on the wire diameter and the wire length. If the DC resistance lies below 0.5 Ohm the red indicator LED „LOOP ERROR“ lights up and the loop output will not be switched on. To increase the resistance please follow the steps below:

Lay out 5 metres of loop cable type H07V-K, with a conductor cross section of 0.5mm², in half.
Wind up both cable ends tightly with each other.
Lay out the twisted cable pair into four loops and fix them with a piece of cord to prevent the cable from unrolling.
Connect one end of the cable loop with the induction loop and the other end with the induction loop amplifier.

The loop resistance is increased by this configuration. Other system parameters are not affected. The looped cable increases the resistance by 0.15 Ohm.

Connecting the induction loop
Connect the ends of the loop wires to the terminals (17) on the rear of the amplifier.

Please note the following information

The loop amplifier must be located outside of the loop.
Twist the cable section between the amplifier and the loop (feed cable to the loop) to prevent interference.
Use a suitable measurement device (e.g. ohm meter) to make sure that the loop doesn’t have a short-to-ground (no damage on the insulation of the loop wiring)!
The distance from the loop level to the normal listening level should be approx. 1.20 m to 2.00 m.

Configuring the amplifier and connecting audio sources
Up to 2 audio sources can be connected to the symmetrical XLR jacks (20).

If a phantom-powered microphone is connected to INPUT1 or INPUT2 a 15 V phantom voltage can also be added with the “Phantom” switch. An extra amplification for each input separatly can be switched on with the switch “Gain Boost”. To connect a CD-Player or a audio amplifier to the induction loop amplifier the input sensitivity of INPUT2 can be switched to “LINE”-level with the “MIC/LINE” switch. In the standard configuration, INPUT2 is configured as „LINE“ without phantom voltage and extra amplification. If you want to alter the standard-setting please switch off the amplifier and set the switches on the desired positions. After setting the switches please switch on the amplifier again.

Using the priority input (18)
You can use the priority input to connect the induction loop amplifier with an alarm system or a PA system. The priority of the priority input is higher than the one of the audio inputs. The signal on the connected induction loop is replaced with the signal of the priority input if a signal is received at the priority input. Please use the volume control to set the volume of the audio signal which the priority input sends to the connected induction loop.

Important note
Put the safety bracket on the priority input to make sure that it is not possible to touch the priority input.

Power supply (15)
The PROLOOP DCCplus induction loop amplifier can be used in countries with 115 V or 230 V mains power supply.

Set the voltage selector (14) to the correct position. Position “115“ for countries with 100 to 120 V (AC) or Position “230” for countries with 220 to 240 V (AC).
Note The voltage selector is set on “230” position when the PROLOOP DCCplus induction loop amplifier is delivered.
Please check if the fuse holder contains the correct fuse. 3 A fuse (T) if the voltage selector is set on “115” or 1.5 A fuse (T) if the voltage selector is set on “230”.
Note A 1.5 A fuse (T) is set into the fuse holder when the PROLOOP DCCplus induction loop amplifier is delivered.
Use a locally approved power cable to connect the loop amplifier to the mains socket.

First-time operation
Before you switch on the device, please turn all the control knobs as far to the left as possible.

Connect a sound source to audio INPUT2.
Connect the loop amplifier to the mains power supply.
Switch the audio source on.
Switch the amplifier on. The indicator for the power supply (3) blinks during the self-test. After about 10 seconds the indicator lights steady and the amplifier is ready for use.
Set the sensitivity of audio INPUT2 to a position where two green LED of the level indicator for compression lights up.
Increase the electric current through the induction loop with the current control (10) on the front of the amplifier. You can read the set current at the level indicator for induction loop current (2). CURRENT
Use the earphone jack (12) to listen directly.

Adjusting the field strength
You will need a field strength gauge (special accessory) to calibrate the system correctly according to the IEC 60118-4 standard.

Metal loss compensation
You will get a loss of the magnetic field strenght if you have strong reinforcement metal in the floor. Compensate this loss, use the metal loss compensation control (6) on the front side of the loop amplifier. Please follow the steps below to set the metal loss compensation:

Turn the Metal loss compensation control to the left position.
Connect headphones to the headphone socket of the amplifier and listen to the audio signal.
Use an inductive loop receiver and the same headphones to listen to the audio signals of the inductive loop.
Turn the Metal loss compensation control to adjust the tone of the audio signal.

Setting up a LOS loop system with PROLOOP DCCplus
If you want to set up a LOS loop system you need two of the PROLOOP DCCplus. The first amplifier will be the master unit and the second amplifier will be the slave unit.

Master and Slave settings

To define the first amplifier as Master amplifier the “0°/90°” switch must be set on 90°.
A connection cable with a 6.3 mm jack will be plugged into the “SLAVE OUT” socket at the Master amplifier.
To define the second amplifier as Slave amplifier the connection cable will be plugged into the “SLAVE IN” socket.
Note The slave amplifier can only send the signal that it receives from the master amplifier to its induction loop. The audio inputs and the priority input of the slave amplifier are disabled.

LOS induction loops
The optimal designs and configurations are always dependent on the venue details, i.e. the floor plans and the sizes of the rooms serviced, the number of internal induction loops and the demands made on low overspill. To determine the corresponding values for the »tailored« low-overspill layout and the optimal level adjustments in each case, it is necessary to use complicated calculation and installation methods. That’s why we recommend that you use the services provided by AUDIOropa. We support architects, technicians and installation experts qualified in the planning of LOS installations.

Installation of the induction loop
To use a LOS system, the induction loop must be installed in a special way. In detail, two separate loops are used (master/slave), which consist of eight- piece segments lined up one after the other. The exact proportions and the exact number of segments depend on the demands made on low overspill as well as the size of the room. The smaller the segment, the smaller the overspill will be. The master loop is laid over the entire area to be serviced. The slave loop is always one segment shorter than the master loop and doesn’t begin until after the first segment half of the master loop. The individual segment lengths should correspond to the distances between the seating rows.
We recommend using a single-strand cable, e.g. H07V-K or the copper ribbon cable (A-4937-0, 50m role / A-4948-0, 100m role).

Advantages of a LOS induction loop design

No loss of field strength in the centre of the induction loop
No horizontal overspill
No signal holes inside the loop

Example of a LOS loop measuring 16×19 metres, approx. 300m²

Fig. Example of a LOS loop

Connecting the induction loops to the master and slave amplifier

The loop amplifiers has to be located outside of the loop.
Connect the “SLAVE OUT” output socket of the Master amplifier to the “SLAVE IN” input socket of the Slave amplifier (See picture below).
Twist the section of cable between the amplifier and the loop (supply to the induction loop) to reduce interfe- rence. (See picture below)
Use a suitable measuring instrument (e.g. ohmmeter) to make sure that the loop is not grounded (no defect in the insulation of the loop system). Typical resistance values for a 300m² loop lie between 0.5 and 3 ohms. Since the master loop is longer, it also has a greater resistance.
Connect the cable ends of the loop to the corresponding terminals (17) on the rear panel of the amplifier. Make sure that you do not mix up the ends of the master and the slave cable.

Adjusting the amplifiers
In order to adjust a LOS system, you will require a field strength gauge, e.g. the FSMplus (A-4292-0).

Before you switch on the amplifiers, turn the input regulators IN1, IN2 and the loop current control CURRENT as far to the left as possible.
Plug in the power cords supplied with the amplifiers and switch the master amplifier on. The power supply indicator (3) blinks for 10 seconds and should light up than.
Before you adjust the line level, don’t forget to apply a test signal to the INPUT2. We recommend using our test CD, which comes with the FSMplus (A-4292-0). Use a 1kHz sine signal (track 3 on the CD) and set the volume control (master fader) on the mixing desk or the audio amplifier as it is normally used at your events.
Adjust the input sensitivity regulator (5) of the INPUT2 so that two green LEDs of the level indicator for com- pression light up on the front panel of the device.
Turn the master current regulator (10) to the central setting. The control indicator (2) on the front panel should now light up.
Set the FSMplus to “Norm” and “0dB scale” and hold it vertically to the induction loop level. The ideal height depends on what the induction loop system is being used for; typically, this might be 1.20m (for seated au- diences) or 1.70m (for standing audiences).
Check the average field strength by running diagonally over the induction loop area and determine the aver- age of the values indicated. The average value has to measure 0dB (±3dB). If you do not obtain this value, adjust the corresponding control until this value is reached. Please note that every time you cross a cable, the field strength will drop briefly. This is normal as long as only one loop is in operation.
Once the master amplifier is adjusted, switch off the master amplifier and disconnect the induction loop.
Now switch on the master and slave amplifier. Important: Do not alter any of the controls of the master amplifier.
Turn the slave current regulator (10) to the central setting. The control indicator (2) on the front panel should now light up.
If you have set up the slave amplifier, switch the master and slave amplifier off.
Re-connect the induction loop of the master amplifier.
Switch on the master and slave amplifer, again.
For the final check, use a normal audio signal, such as music or voice via the microphone and check the field strength with the FSMplus. The value should read 0dB (±3dB) in the signal peaks. If you do not read these values, repeat the measurement process starting from Step 3 and set the controls higher than for the first test.
If the values lie within the stipulated range, the amplifiers are set to the ideal levels. Use the headphone jack of the FSMplus to evaluate the sound of the signal with a pair of headphones.

Warranty

The PRO LOOP LOS induction loop amplifier exhibits very high operating safety. If any malfunctions should occur, despite the correct operation, please contact your retailer or the manufacturer. The guarantee covers repairs and shipping free of charge. The device must be returned in its original packaging – do not discard it. The guarantee becomes invalid if the device is operated incorrectly or any repairs are attempted by unauthorized persons (de-vice seal is broken). Repairs will only be made on the guarantee if you also include the correctly completed guaran-tee card and a copy of the retailer’s invoice/receipt. The device number must always be included.

Environmental protection/disposal
Disposal of used electrical and electronic devices (applicable in EU countries and other European countries with a separate collection system for these devices.) The symbol on the product or its packaging in- dicates that this product should not be thrown into the regular household waste; it should be taken to a recycling centre for electrical and electronic devices. When you dispose of this product correctly, you make a contribution towards protecting the environment and your health. Incorrect disposal can pose a threat to the environment and your health. Material recycling also helps to reduce the use of raw materials. Further information on recycling this product is available from your community, the municipal waste disposal department or the retail outlet at which you bought the product.

PRO LOOP DCCplus specifications

Power supply 115 – 230 V AC, 50-60 Hz, 150 W
Coverage 1000 m² acc. to IEC 60118-4
Induction loop output
Max. current 12 A RMS, continuous 1 kHz, short-circuit-proof
Max. voltage 32 V RMS
Frequency range 100 – 5000 Hz (±3 dB)
Distortion < 1 %
Cable connection 2 screw connections on the rear panel of the device
Outputs
Headphone jack 3,5 mm
Slave Out 6,3 mm jack, 0°/90° adjustable phase shift
Inputs
IN 1 XLR connector, Microphone-in (symmetric, sensitivity: 1mV)
IN 2 XLR connector, optionally LINE-in (symmetric, sensitivity: 1V) or
Microphone-in (symmetric, sensitivity: 1mV)
Amplification adjustment, phantom current 15V can be added
100V-priority inp
Controls and regulators
Loop current adjustment by control dial
Amplification adjustment for IN 1 and IN 2 by control dial
Metal loss compensation by control dial
Indicators
Power supply 1 green LED
Input level 5 green LED and 1 yellow LED
Induction loop current 5 green LED and 1 yellow LED
Overload 1 yellow LED
Overheat 1 red LED
Loop error 1 red LED
Induction loop monitor over a 3.5 mm jack for headphone connection
Dimensions 90 x 430 x 270 mm (H x W x D)
Colour Black
Weight 7,8 kg

This device satisfies the following EU directives:

2011 / 65 / EC RoHS directive
2012 / 19 / EC WEEE directive
2014 / 30 / EC EMC directive
2014 / 35 / EC Low voltage directive

Compliance with the directives listed above is confirmed by the CE seal on the device. CE compliance declarations are available on the Internet at www.audioropa.com Technical specifications subject to change without notice.