User Manual

Redback® A 4205 Kiosk Loop Amplier
www.redbackaudio.com.au
Redback® Proudly Made In Australia2
1.0 INTRODUCTION
Induction Loop ampliers, also known as T-loop or Hearing Loop ampliers, are installed to greatly enhance the listening
experience of people using hearing aids. The hearing loop, as its name suggests, is basically a loop of wire which
surrounds a designated area to transmit audio to a hearing aid. An audio source is fed into the Amplier, and the output
of the amplier then sends a high current signal into the loop, which generates a magnetic eld. The magnetic eld is
then picked up by the Telecoil inside a hearing aid.
Hearing Loops are commonly installed in public areas which are generally noisy, making it difcult for hearing impaired
users to hear clearly. The A 4205 amplier model has been engineered to meet AS60118.4-2007 and includes a compres-
sor/limiter circuit with tailored frequency response ensuring excellent speech intelligibility. It will operate into loads of less
than 2 ohms and is short circuit proof.
The amplier is ideally suited for small installations such as ticket booths, information desks, emergency room interview
windows, reception desks etc and has a coverage up to about 1m.
The A 4205 3VA model delivers 0.3A RMS, 0.35 Amps peak into a typical Loop Resistance of 0.2Ω to 1.7Ω (max 2Ω).
Inputs are provided for 3 pin XLR balanced mic with phantom power and a dual auxiliary input. The unit is powered from
12V DC (plugpack supplied).
2.0 FRONT PANEL GUIDE
Figure 1 shows the layout of the front panel.
Fig 1
1 Mic volume control 2 Signal Presence Indicator 3 Aux volume control
4 VU Indicator 5 On Indicator 6 Power Switch
4.0 REAR PANEL CONNECTIONS
Figure 2 shows the layout of the rear panel.
Fig 2
1 DC Fuse (800mA)
This fuse protects the amplier.
2 12V DC Input
Connect 12V DC to either of these inputs. A 12V DC plugpack is supplied for connection to the 2.1mm socket.
Timer
Power
On
0
2
4
6
8
10
Mic
Aux
Signal
Present
0dB-3dB
-6dB
-9dB
0
2
4
6
8
10
Timer
3VA Loop Amplifier
A 4205
1
2
3 4
5
6
L
R
Mic Input
+
OUTPUT
_
Aux input
+
-
Made in Australia by
Altronic Distributors
Pty Ltd
www.redbackaudio.com.au
12VDC
Input
+
12V DC
Input
_
DC Fuse
2 1
3
1 2 3 4 5 6