Ampligram AG1

BSR (Brand), Birmingham Sound Reproducers Ltd.; Staffordshire

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  • Year
  • 1933 ?
  • Category
  • Sound/Video Recorder and/or Player
  • Radiomuseum.org ID
  • 358754
    • Brand: Birmingham Sound Reproducers

Click on the schematic thumbnail to request the schematic as a free document.

 Technical Specifications

  • Number of Tubes
  • 3
  • Main principle
  • Audio-Amplification
  • Wave bands
  • - without
  • Details
  • Record Player (not changer)
  • Power type and voltage
  • Alternating Current supply (AC) / 50 Hz, 190-250 Volt
  • Loudspeaker
  • Permanent Magnet Dynamic (PDyn) Loudspeaker (moving coil)
  • Power out
  • 5.9 W (max.)
  • Material
  • Wooden case
  • from Radiomuseum.org
  • Model: Ampligram AG1 - BSR Brand, Birmingham Sound
  • Shape
  • Tablemodel, Box - most often with Lid (NOT slant panel).
  • Dimensions (WHD)
  • 21.5 x 11.75 x 17 inch / 546 x 298 x 432 mm
  • Notes

  • The BSR Ampligram was an innovative electric amplifier and gramophone unit introduced in 1933. It featured a powerful 5.9-watt undistorted output, making it suitable for public entertainment. The unit was housed in a compact, portable oak case measuring 17 x 21.5 x 11.75 inches.

    Key features of the Ampligram included:

    • Two-stage amplifier
    • Electric gramophone motor with automatic stop
    • Marconiphone pick-up
    • Tone and volume controls
    • High-grade moving-coil milliammeter
    • AC-operated with adjustable mains input (190-250V, 50Hz)
    • Output transformer with three ratios for speaker matching (2, 7.5, and 15 ohms)

    The amplifier used an AC/SG valve in the first stage, followed by a PP5/400 valve in the output stage. A UU120/500 full-wave rectifier valve provided high tension.

    Two models were available:

    • AG1: Standard model
    • AG2: Included provisions for microphone attachment with a special input transformer and changeover switch

    The Ampligram was praised for its exceptional sound quality, particularly its bass response. It maintained constant amplification from 50 to 5,000 Hz, with attenuation above this range to reduce needle scratch.

    Price:

    Model AG1: £26 10s

    The Ampligram represented a significant advancement in electric gramophone technology, setting a new standard for audio reproduction in its time.

  • Price in first year of sale
  • 26.50 GB £
  • Author
  • Model page created by Gary Cowans. See "Data change" for further contributors.

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