• Year
  • 1997 ??
  • Category
  • Audio Amplifier or -mixer
  • Radiomuseum.org ID
  • 344785

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

 Technical Specifications

  • Number of Tubes
  • 12
  • Number of Transistors
  • 11
  • Semiconductors
  • Main principle
  • Audio-Amplification
  • Wave bands
  • - without
  • Power type and voltage
  • Alternating Current supply (AC) / 100-125, 220 Volt
  • Loudspeaker
  • - For headphones or amp.
  • from Radiomuseum.org
  • Model: Preamplifier PV9 - Conrad-Johnson Design, Inc.;
  • Dimensions (WHD)
  • 19 x 5.25 x 14.25 inch / 483 x 133 x 362 mm
  • Notes
  • Hybrid stereo preamplifier, more complex than the PV6 model, with anodic power supply separated from the filament power supply circuit.
    Two ICs provide to stabilize the supply voltage of the filaments. The first stabilizes the voltage of the first two valves which are the amplifiers of the magnetic phono input.
    The second separates these two from the other four providing for the stabilization of the supply voltage.
    The ignition circuit of the valve filaments is not connected to ground. 
    A special circuit (Anti Bump) short-circuits the outputs to ground for a few seconds when switched on.
    Inputs: Tape 1, Tape 2, CD, Tuner and Phono RIAA equalized.

    The schematic of only right channel is shown, the left is obviously identical.
    The power supply schematic is instead complete.

    Consisting, all the preamplifier of 12 valves, 11 transistors, 45 diodes and 8 rectifier diodes. Transistor and ICs codes are not listed.

  • Net weight (2.2 lb = 1 kg)
  • 20 lb (20 lb 0 oz) / 9.080 kg
  • Mentioned in
  • -- Original-techn. papers. ("Il Fascino delle Valvole" Italy, by Massino Casolaro EDIFAI editor, January 1997)
  • Literature/Schematics (1)
  • - - Manufacturers Literature (Owner Manual PV9 Vacuum Tube Preamplifier, Conrad-Johnson Design, 703-698-8531)
  • Author
  • Model page created by Pier Antonio Aluffi. See "Data change" for further contributors.

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