Bosch Loop Amplifier for Hearing Impaired

Hearing-aid users can set their devices to the Tmode setting to receive the signal coming from the loop. They receive announcements in excellent audio-quality, without the background noise or reverberations that normally impair intelligibility for people with hearing disabilities.

• High power, current driven amplifier
• Two microphone/line inputs, one priority input (100 V)
• Selectable frequency range and tone controls
• Limiter and automatic gain control (AGC)
• Integrates in an EN 54-16 and EN 60849 compliant system

High power, current driven amplifier Two microphone/line inputs, one priority input (100 V) Selectable frequency range and tone controls Limiter and automatic gain control (AGC) Integrates in an EN 54-16 and EN 60849 compliant system

The loop amplifier can be connected to a mixing amplifier's line level output, or it can accept up to two microphone/line signals directly. A 100 V priority input is available for uplink to a voice alarm system. This input can be monitored for the presence of a pilot tone. The built-in supervision monitors all key functions of the loop amplifier, and the fault state is available on a fail-safe relay. This makes it possible to use the Plena Loop Amplifier in an IEC 60849 compliant system, and to include the induction loop in the supervised transmission paths.

For added ease, the loop amplifier is equipped with a limiter that keeps the output field strength below the prescribed 100 mA/m. This circuitry can also be set to an automatic gain control (AGC) that amplifies weak signals for enhanced intelligibility, while attenuating loud signals. This ensures that all information is presented at a comfortable listening level.

The unit has tone controls and a metal loss compensation circuit to adjust the sound to the program material and the environment. The controls have locks to prevent unwanted access after they have been adjusted. The Plena loop amplifier is stackable (master/slave configuration) to cover very large areas, and supports low spillover schemes. Its unique quadrate configuration provides uniform field strengths even over multiple loops.

Specifications:

• Operating Temperature: -10°C to +55°C
• Weight: 11.6Kg
• Mounting: Stand-alone, 19" rack
• Dimensions: 94x430x320mm
• Line Output: 1
• Master Input: 1 (*See Product information sheet)
• Priority Input: 1
• Mic/Line Input: 2
• Hi Control: Max ±8dB (frequency is setting dependent)
• Low Control: Max ±8dB (frequency is setting dependent)
• Distortion: <1% @ rated output power, 1 kHz
• Frequency Response: 50 Hz to 10 kHz (+1/-3 dB @ -10 dB ref. rated output)
• Output Current: 10.0 A
• Power Consumption: 500 VA
• Inrush Current: 7/14 A (230/115 VAC)
• Voltage: 115 - 230 VAC ±10%, 50/60 Hz