Redback A 4210 80VA / A 4212 280VA Hearing Induction Loop Amplifiers: Operating Manual, revision 1.2

Summary

A loop-amplifier manual documents a dedicated emergency input that can take priority over microphone and programme inputs.

Key findings

• Page 4 describes audio feeding an amplifier and loop, with reception by the telecoil in a hearing aid. It identifies an EWIS input for connection to venue emergency evacuation systems.
• Page 8 describes an emergency controller or tone generator feeding the EWIS input. When the enabled voice-operated switching circuit detects audio on that input, it overrides microphone, line and auxiliary inputs.
• Pages 8–9 describe adjustable sensitivity and a switch that enables or disables this priority function, so the emergency input’s behaviour depends on configuration.
• Page 4 specifies 240 V AC operation. Page 9 says the amplifier shuts down on excessive temperature to prevent damage.

Limits

Manufacturer instructions for two models, read as the original manufacturer PDF from a reseller. No independent evacuation trial, battery endurance test or assessment to a fire-alarm standard is reported. The emergency input is evidence of an audio-routing capability, not of emergency availability throughout a venue.

Read the original

www.wiltronics.com.au/wp-content/uploads/datasheets/redback-hearing-induction-loop-amplifier-280va-instructions.pdf

Link checked 13 October 2026. We link to the original and do not host copies.

Cited in

• Can assistive listening carry emergency and evacuation announcements?Partly answered

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