RDL SF-PA50AX 50W 70/100V Audio Amplifier (Export Model, No Power Cord)

RDL SF-PA50AX 50W 70/100V Audio Amplifier (Export Model, No Power Cord)

RDL SF-PA50AX 50W 70/100V Audio Amplifier (Export Model, No Power Cord)

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Expected availability: 7-10 business days

Product Highlights

  • Analog Input to Constant Voltage Output
  • 50W Class-D RMS Power at 70 or 100V
  • Adjustable Input Gain
  • Terminal Block & 3.5mm Inputs
  • Terminal Block Output
  • Supports VCA Control
  • Thermal & Short-Circuit Protection
  • Power via Included 24 VDC Power Supply
  • Durable Metal Enclosure
  • Made in the USA
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This item is noncancelable and nonreturnable.

$0.00 Tax Collected Outside NY and NJ

You Pay: $319.95

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RDL SF-PA50AX overview

  • 1Description

The RDL SF-PA50AX is a SysFlex series 50W 70/100V mono audio amplifier designed to convert one analog input to a constant voltage amplified output for A/V technicians, system installers, and audio engineers in office buildings, retail environments, and educational facilities. Its Class-D output stage delivers 50W of RMS power at 70 or 100V from a balanced or unbalanced analog input, which offers adjustable gain via a rear-panel, single-turn potentiometer.

Connect a balanced analog source to the mono terminal block input, or utilize the unbalanced 3.5mm stereo mini jack to route signal from a mobile device. The terminal block output accommodates connection to 70 or 100V speakers, and a detachable terminal block is provided for hookup of remote control of the internal VCA. Thermal and short-circuit protection guard against electrical damage and unintended shutdown.

The SF-PA50AX supports powering via the included 24 VDC external power supply (power cord available separately), or from proper wiring to the terminal block power input. Engineered and manufactured in the USA, it boasts a durable metal enclosure for reliable toughness.


Converts one analog audio input to a 70 or 100V constant voltage amplified output
High-efficiency Class-D output stage produces minimal heat for all levels of expected voice or music modulation
Balanced mono terminal block input
Unbalanced 3.5mm stereo mini jack automatically sums the left and right channels to mono
Input gain is set by the installer using a rear-panel, single-turn potentiometer with an associated dual-LED VU meter calibrated to 20 dB below maximum power output
Supports powering via the included 24 VDC external power supply or 24V connection to the dedicated terminal block power input
LED Mute indicator glows yellow when the output is muted
Amplifier power is monitored and the current is limited to protect the power supply against shutting down, even during extreme feedback or square wave modulation conditions
Red rear-panel LED flashes when the SF-PA50AX reduces power consumption to prevent shutdown of the power supply
Equipped with an internal VCA for setting the output level
Detachable terminal block provides for the connection of an external 10-kOhm potentiometer or a 0 to 10 VDC control voltage
Amplifier gain remains at maximum when the VCA input terminal is not connected
RDL remote controls are available to provide single-turn, multi-turn (rotary encoder), or button (ramp or fixed-level selection) user level control
Constructed in a durable all-metal enclosure suitable for free-standing, surface-mounted, or rack-mounted operation
Engineered and manufactured in the USA for continuous duty in demanding installations
In the Box
RDL SF-PA50AX 50W 70/100V Audio Amplifier (Export Model, No Power Cord)
  • 24 VDC Power Supply
  • Limited 3-Year Warranty
  • Table of Contents
    • 1Description

    RDL SF-PA50AX specs

    Inputs 1 x 1/8" / 3.5 mm stereo mini jack (unbalanced)
    1 x detachable terminal block (balanced)
    Outputs 1 x terminal block for 70/100 V output
    Control 1 x detachable terminal block for VCA control
    Amplifier Class-D
    Amplifier Output 50 W RMS (70 or 100 V)
    Maximum Input Level Balanced: +25 dBu (before clipping)
    Unbalanced: +10 dBV (before clipping)
    Nominal Input Level Balanced: +4 dBu (adjustable)
    Unbalanced: -10 dBV (adjustable)
    Minimum Input Level Balanced: -10 dBu (for 20 dB below full output power)
    Unbalanced: -25 dBV (for 20 dB below full output power)
    Gain Adjustment Single-turn audio taper (with associated dual-LED VU meter calibrated to 20 dB below full output power)
    Input Impedance Balanced: > 10 kOhms
    Unbalanced: > 5 kOhms
    Common Mode Rejection > 60 dB (50 to 120 Hz)
    Frequency Response 50 Hz to 20 kHz (+0 / -3 dB)
    THD + N < 1% (1 kHz)
    Noise Below Maximum Power: < -90 dB
    Below 1/8 Power: < -80 dB
    VCA 0 to 10 VDC control via detachable terminal block (compatible with RDL VCA wall controls)
    Ambient Operating Environment 32 to 104°F / 0 to 40°C (68°F / 20°C recommended)
    Indicators Front-Panel: Power (blue), amplifier muted (yellow)
    Rear-Panel: Overload protect (red), dual-LED VU meter (two)
    Plenum Number UL 2043
    Power Requirements 24 VDC at 2700 mA via 100 to 240 VAC, 50-60 Hz, IEC C14 power supply or connection to terminal block power input
    Enclosure Material Metal
    Dimensions (W x H x D) 5.8 x 1.7 x 6.4" / 14.8 x 4.3 x 16.4 cm
    Weight 5.9 lb / 2.7 kg
    Country of Manufacture United States of America

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