LP-23  Telephone simulator

The LP-23 Telephone Simulator is a specialized processor designed to simulate telephone, radio and intercom sound easily, without patching in a multitude of outboard devices. The telephone filter section is equipped with extended range High-pass and Low-pass filters and a balance control for adjustment between direct and filtered signal.



  LP-23 Technical Information and Review in PDF:


  • Band-pass filter with sweep frequency and a variable Q.
  • Boost control up to 15dB.
  • Distortion generator with variable harmonics.
  • Noise generator with dedicated filters.
  • Noise signal can be used alone to simulate wind effects.
  • Pink noise is running continuously .and is available on a separate jack socket for external process or sound level measurement purposes.
  • Voice-over circuit reduces noise level when speech signal is present.
  • Adjustable attenuation depth.
  • Gate threshold controlled by squelch potentiometer.
  • Independent in / out control on each function.
  • Output stage gain control to compensate for signal loss caused by narrow bandwidth.
  • Squelch circuit functions like a sharp noise gate cutting both signal & background noise.
  • Change-over switch toggles between telephone signal and direct clean signal.




    Maximum Input Level: +22.5dBm

    Maximum Output Level: +22.5dBm

    Unfiltered Frequency Response @ 1dB: 5Hz to 100kHz

    Unfiltered Distortion at 1kHz: 0.0016%

    Unfiltered Signal to Noise Ratio: -96dB

    High Pass Telephone Filter: 35Hz to 2kHz @ 18 dB per octave

    Low Pass Telephone Filter: 800Hz to 18kHz @ 18 dB per octave

    Presence Filter: 400Hz to 7kHz 0/+ 15dB

    Pink Noise Generator: 30Hz to 20kHz -7dB Max

    Pink Noise Filter: 40Hz to 2kHz; 800Hz to 20kHz @ 12 dB per octave

    Distortion Amplifier: 0.008% set at center; 21% at maximum

    Gain Correction: +/- 10dB

    Power Requirements: 115VAC/60Hz / 220VAC/50Hz

    Dimensions: 19" x 1U (19" x 1.75" x 8.9") / (483mm x 44.5mm x 225mm)

    Shipping Weight: 11 pounds



    Lafont Users Include:

    4MC; All Post; American Zoetrope; AstralTech; Brasher Sound; Buzz Audio; Bark Audio; C.B.S. TV; Casablanca Sound; Chace Productions; Chicago Audio; Chicago Pacific Recording; Cliff Schwarz Recording; Cinar Films; Creative Cafe; Enterprise Post; Flying Monkey; International Recording; Location Sound; Magno Sound; Millennium Studios; Medallion PFA; Post Modern Sound; Novastar; Olympic Sound Studios; Sonolab; Soundfirm; Paramount Pictures; Premier Post; Signet Sound; Skywalker Sound; Sony Pictures; Sound One; The Beach; The Walt Disney Company; Todd AO Studios; Universal Pictures; Virtuality Recording; Warner Brothers; Warrenwood Studios; Westwind Media; 20th Century Fox