18 W Mono Hi-Temp Audio Amplifier - 8 Ω, with Power Supply

  • 18 Watts RMS into 8 Ω
  • Operation in Elevated Ambient Temperatures to 70°C
  • Input / Output Detachable Terminal Block Connections
  • Line Level Balanced or Unbalanced Input
  • Compressor/Limiter Controls Clipping
  • LED to Indicate Audio Compression Threshold
  • Compressor Produces Maximized Average Output Power
  • Audio Quality Superior to Standard Amplifiers
  • Ultracompact All Metal Construction
  • High Efficiency Class D Operation
  • Thermal and ShortCircuit Protection
  • Recommended Power Supply ( Included )
    PS-24KS (USA)PS-24KX (International)


    The FP-PA18H is a high efficiency 18 W power amplifier with a line input, 8 ohm output and audio compressor capable of operation in a high ambient temperature environment. The thermal characteristics of the module case and construction throughout using high temperature components permit operation over a range of 0 to 70 degrees C. The FP-PA18H is ideally suited to outdoor applications, signage and other installations where ambient temperatures may become elevated due to limited convection.

    (Note: The power supply must be mounted in a location with a maximum ambient temperature of 40 degrees C. The FP-PA18H module is available separately for installation with a high temperature power supply or in systems with distributed 24 Vdc power. Contact RDL technical support for more details.)

    The FP-PA18H features a balanced line level input that may be connected unbalanced. A gain control located next to the terminal block is designed to be adjusted manually or with a trimming screwdriver. The gain range will accommodate standard unbalanced levels as well as professional balanced levels. The output drives one 8 ohm speaker or multiple speakers connected to present an 8 ohm load to the amplifier.

    The FP-PA18H includes an analog compressor/limiter for fidelity audibly superior to conventional class D amplifiers with digital limiting. The input GAIN setting determines whether the limiter alone is used for clipping suppression, or if the full compressor/limiter will be used to substantially increase the average output power beyond that of a standard 18 W amplifier. A red COMPRESSION LED flashes when the limiter is preventing output clipping. Normal audio level signals remain unaffected by the compressor thereby preserving audio dynamics. If the input level is increased so that the compressor is active, the LED remains dimly lit between peak flashes. The audio is compressed according to three dynamic time constants providing aural transparency while maintaining clean, unclipped amplified audio for input overloads of up to 20 dB. The FP-PA18H, with compression, is capable of producing average audio output levels and clarity normally expected from amplifiers with a much higher output power rating.

    The output stage includes an audio detector that illuminates the green OUTPUT ACTIVE LED and provides an active open collector output when the output stage is active and amplified audio is present at the module output. This output is useful to control other equipment or to verify amplifier operation using high or low frequency low level test tones. The detector triggers with only 30 mW of output power at 20 Hz or 5 mW of output power at 20 kHz.

    A blue POWER LED illuminates when the FP-PA18H is powered from its external 24 Vdc power supply. The module is equipped with both thermal and output short circuit protection. The high efficiency Class D output stage produces minimal heat for all levels of expected voice or music modulation.

    Wherever an ultra compact, high quality, high efficiency audio power amplifier is needed to provide reliability and unsurpassed versatility, the FP-PA18H is the ideal choice. Use the FP-PA18H individually, or combine it with other RDL products as part of a complete audio/video system.


    Input:Line level (+4 dBu nominal balanced; 10 dBV nominal unbalanced)
    Input Impedance:10 kΩ balanced bridging; 5 kΩ unbalanced
    Gain Adjustment:Single turn audio taper
    Minimum Input Levels:Balanced: 18 dBu (to cross compressor threshold)
    Unbalanced: 20 dBV (to cross compressor threshold)
    Maximum Input Levels:Balanced: +23 dBu
    Unbalanced: +21 dBV
    Frequency Response:20 Hz to 20 kHz (+/ 1 dB)*
    THD+N:< 0.5% (20 Hz to 20 kHz)*
    Compressor:Threshold 3 dB below rated output, automatically adjusting attack and release times
    CMRR:> 45 dB (50 Hz to 3 kHz)
    Noise:< 72 dB (below 18 W RMS, +4 dBu input)
    Output Power:18 W RMS into 8 Ω
    Output Circuit:Class D
    Output Signal Detector Threshold:30 mW @ 20 Hz; 20 mW @ 30 Hz; 10 mW @ 50 Hz;
    5 mW @ 65 Hz through 20 kHz
    Output Signal Detector Output:Open collector, 5 mA
    Ambient Operating Environment:0° C to 70° C Maximum
    Indicators (3):Red LED: COMP LED indicates compressor activity
    Green LED: OUTPUT ACTIVE (controlled by output signal detector)
    Blue LED: POWER on
    24 Vdc power supply current:80 mA (idle), 975 mA (max.), Ground referenced
    Power Supply (included):100 to 240 Vac, 50-60 Hz, 1A max.; 24 Vdc output to module
    Dimensions:Height: 1.15 in.(2.92 cm); Width: 3.25 in.(8.26 cm); Length: 3 in.(7.62 cm)
    *measured at compressor threshold level equaling 12 W RMS output power
    Package Type:Cardboard Box
    Tariff code:8543.70.9910
    WEEE weight:0.755 lbs.
    Shipping Weight:1.03 lbs.
    Package Dimensions:4.375 x 7 x 2.25 in.

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    Engineering Functional BlockAmericanDXF
    Panel Diagram - FrontAmericanDXF
    Panel Diagram - FrontMetricDXF
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