Low Frequency Multi-Application Loud Ringer and Paging Amplifier

By: Algo Communication Products  09-12-2011
Keywords: Machine shops, Lunch Rooms

The Algo 1825 Duet Plus is a high performance low-frequency loud ringer compatible with most business telephone systems in office and industrial applications. The unit is compatible with dry contact closure, analog telephones, and Nortel digital telephones including Norstar, Business Communication Manager (BCM), Meridian 1, and Communication Server 1000 (CS 1000).

Loud ringing can be activated by a relay or switch closure (dry contacts), low voltage detection, 90V analog telephone ringing, or any Nortel TDM digital business telephone.

Non-Irritating Tone Output

Amplified Voice Paging

An additional feature of the 1825 Duet Plus is its capability to provide amplified voice paging as a separate application or in combination with loud ringing utilizing the same speaker. For small business telephone systems this provides an extremely cost effective and high performance solution for loud ringing and loud paging into a warehouse, storage yard, or machine shop.  Separate volume control is provided for voice page and loud ring levels.  

Other useful features include adjustable warble frequency, adjustable volume, and integrated test button.


Key Features

  • Low frequency tone output provides effective non-irritating notification of telephone and paging signals
  • Adjustable volume and frequency controls to suit user preferences
  • Dry contact activation from push-button, door-opening controller, or KSU Night Bell/Auxiliary Ring contacts
  • Auxiliary speaker outputs for connection to existing paging systems
  • Convenient 90 volt ring detection with inputs for Tip and Ring
  • Operational from the headset jack of Norstar and selected Meridian 1 station sets
  • Designed for easy wall-mounting
  • Power supply included


  • Machine shops
  • Warehouses
  • Outdoor work yards
  • Factories
  • Farms
  • Lunch rooms
  • Hearing impaired

Audio Sample from 1825 Duet Plus

Description Product Code

Keywords: Lunch Rooms, Machine shops,

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