Cabot 25-Watt High Quality Amplifier

Radford Electronics Ltd.; Bristol

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  • Year
  • 1949 ?
  • Category
  • Audio Amplifier or -mixer
  • Radiomuseum.org ID
  • 360433

 Technical Specifications

  • Number of Tubes
  • 7
  • Main principle
  • Audio-Amplification
  • Wave bands
  • - without
  • Power type and voltage
  • Alternating Current supply (AC) / 50 Hz, 110 - 230 Volt
  • Loudspeaker
  • - This model requires external speaker(s).
  • Power out
  • 25 W (undistorted)
  • Material
  • Metal case
  • from Radiomuseum.org
  • Model: Cabot 25-Watt High Quality Amplifier - Radford Electronics Ltd.;
  • Shape
  • Tablemodel, Box - most often with Lid (NOT slant panel).
  • Notes

  • The Cabot 25-Watt High-Quality Amplifier, advertised by Cabot Radio Co. Ltd in 1949, was a versatile audio amplifier designed for various applications requiring sound amplification. This amplifier bears a striking resemblance to the Arthur H. Radford "Amplifier, Modified, Ex US Military," which Radford advertised in December 1948 which was a modifying surplus US military 25W TG10 Keyer amplifier.

    Technical specifications and features of the Cabot amplifier:

    Power and Output

    • Output power: 25 Watts
    • Output impedance: 4-8 or 15 ohms
    • Power supply: 110-230V, 50 Hz

    Input and Controls

    • Separate microphone and gramophone inputs for mixing
    • Microphone input compatible with moving coil or other types as required
    • Gramophone input suitable for standard magnetic or lightweight pick-ups
    • Tone control included

    Valve Configuration

    • 6SN7: Microphone and gramophone mixer
    • 6SJ7: Amplifier stage
    • 6N7: Phase splitter
    • 6L6: Push-pull power amplifier (likely a pair)
    • 5U4G: Rectifier

    Design Features

    • Incorporated negative feedback for improved performance
    • Housed in a steel cabinet with a black crackle finish
    • Engraved front panel

    Applications

    • The amplifier was marketed as suitable for:
    • General public address (P.A.) work
    • Youth clubs
    • Home use as a gramophone or radio amplifier

    Like the earlier amplifier, the Cabot amplifier's design, incorporating a push-pull output stage and negative feedback, was typical of high-quality amplifiers of the era. The use of a 6SN7 dual-triode for mixing, followed by a 6SJ7 pentode amplifier stage, provided good gain and flexibility for various input sources. The 6N7 phase splitter fed the push-pull 6L6 output stage, which was capable of delivering the specified 25 watts of power. The 5U4G rectifier was a common choice for providing high-voltage DC to the amplifier stages.

    The similarities between the Cabot and the Radford "Modified, Ex US Military" amplifier suggest a possible rebadge of the earlier model with a 110 – 230 V AC power supply transformer.

    Priced a £16/10- complete.

    Note: the 1948 original version was £8/13/6 including the stepdown to 110 V mains transformer. 

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

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