The Current Thinking ET30 Loop Amplifier is an audio frequency Induction Loop Amplifier (AFILS). The unit is designed for user-friendly installation to walls, vanity panels, desks and counters. The unit is compact, printed with the AFILS logo as well as text boxes to allow the name of the responsible person and their contact number to be written in. The controls (Mix and Drive) are recessed to hinder unauthorised adjustment, and LED indication is provided for the presence of power and loop current.

The amplifier has two inputs to accept microphones, other signal levels can be accommodated using the relevant Current Thinking adaptor. The inputs are mixed together and the balance between the two inputs is set with the mix control, this allows the unit to operate with a main microphone and an ambience microphone if required, or in a TV lounge to allow a scart connection to the television to be balanced with an ambience microphone for conversation.

The unit incorporates the latest design in audio processing allowing varying microphone levels to be compensated for automatically while preventing any sudden loud noises from reaching the output stage. Compressor design automatically adjusts the release time providing high quality music with a slow release and speech with a relatively fast release. The compressor ratio is dynamically variable and will automatically change from 1:1 to over 20:1 in the case of limiting.

An automatic noise suppression system is further provided, reducing the level of audible hiss from the compressor as gain is added to the system. Output stage for the ET30 incorporates a true constant current design, which will drive loop coils from 0.1W to 1W and is specifically designed for single turn loops in rooms. The output level is set using the drive control and is protected against over temperature; DC offset and has a soft start facility removing loud clicks and pops when the unit is turned on.

Product Applications

The following are a few examples of the uses for the ET30 AFILS amplifier, including the likely accessories required.

• Counters: Using the Telecoil, with either the clip or desk microphone
• Meeting Rooms: Using a Loop Cable and either desk or clip microphone
• Interview Rooms: Using the Telecoil on the desk, with the desk microphone
• TV Lounges: Using a Loop Cable and Scart Lead, with optional microphone
• Sheltered Housing: Using Loop Cable, Clip Microphone and doorbell interface