SF-PA50A 50 W Mono Audio Amplifier - 70 V or 100 V

The amplifier unit shall receive one analog audio source and provide one 70V and one 100V analog amplified constant voltage speaker output on a front-panel detachable terminal block.  The maximum output power shall be 50 W.   The outputs shall provide a noise floor better than 80 dB below 1/8 power operating level from 20 Hz to 20 kHz and better than 90 dB below rated output power. The output frequency response at 50 Hz and at 20 kHz shall not deviate more than 3 dB from the output amplitude at 1 kHz. The output level shall be adjustable using an external dc voltage source between 0 and 10 Vdc. The unit shall produce an audio taper attenuation for linear changes in the control voltage. The unit shall provide a 10 Vdc precision reference permitting an external potentiometer to provide the control voltage to the unit. The unit shall be directly compatible with RDL VCA switched and variable wall controls and with external linear taper potentiometers.

The analog audio source shall be equipped for connection from a balanced line-level source or from an unbalanced stereo source.  The balanced source shall connect through a detachable terminal block. The unbalanced stereo source shall connect through a Mini-Jack, with the L and R input channels actively summed.  A gain trimmer shall be provided to receive balanced operating levels between -10 dBu and +25 dBu, and unbalanced operating levels between -20 dBV and +10 dBV.  An associated dual-LED VU meter shall be provided for gain trimmer adjustment.  The meter shall be calibrated to a level 20 dB below rated output power.

The unit shall be constructed in an aluminum and steel enclosure equipped for mounting to any flat surface and compatible with RDL SysFlex mounting accessories. The unit shall operate from an included 24 Vdc power supply accepting a mains input range of at least 110 VAC to 240 VAC.  The unit shall provide power supply overload protection circuitry that instantaneously and continuously, if necessary, limits the power demand of the unit from the power supply any time the waveform of the audio source signal would, when amplified, instantaneously or continuously require excessive power from the supply.  The unit shall be plenum rated under the standard UL 2043. The unit shall be covered by a 3 year factory warranty. The amplifier shall be an RDL SF-PA50A.