RDL SF-PA100A Format-A Selectable Input / 100W Mono 70V / 100V Constant Voltage Amplifier

Description

The SF-PA100A is a Format-A compatible audio power amplifier designed to convert a selected Format-A audio pair into a mono constant voltage output. It delivers up to 100 watts RMS into 70 V or 100 V distributed speaker systems. The unit is engineered for continuous duty and professional AV installations.

Key features include a three-position selector to choose Pair A, Pair B or Pair C from the Format-A input, loop-through RJ45 output for daisy-chaining additional receivers, and a remote level control option via RJ45. The amplifier uses a high-efficiency Class D output stage to minimize heat and maximize reliability. A selectable compressor adds up to 15 dB of headroom while remaining aurally transparent.

Performance is tuned for installed audio systems with a frequency response of +0/-3 dB from 50 Hz to 20 kHz and THD+N under 1% at full rated power. Input gain is set with a rear-panel single-turn potentiometer and monitored by a dual-LED VU meter calibrated to 10 dB below maximum output. The SF-PA100A also incorporates thermal and short-circuit protection to safeguard the amplifier and connected speakers.

Connectivity is centered on Format-A RJ45 I/O for signal and power distribution plus a REMOTE CONTROL RJ45 jack that accepts RDL D-RLC10KM wall controls, a 10 kΩ potentiometer, or a 0 to 10 Vdc control voltage. The included external power supply accepts 100 to 240 Vac and provides 48 Vdc to the module. Format-A signal pairs and power pass through the LOOP OUT jack to feed additional modules or amplifiers.

The SF-PA100A is well suited to paging, background music, and distributed audio systems in commercial venues that require constant voltage amplification. Its selectable compressor, VCA remote control capability, and loop-through topology simplify multi-zone deployments and system expansion. Plenum rating per UL 2043 supports installation in air-handling spaces.

Installation and operation are simplified by a compact all-metal enclosure that supports free-standing, surface, or rack-mounted use. An internal VCA enables long-term noise-free level adjustment, and front-panel LEDs provide status, output level, and Format-A power indication. The amplifier ships with the required external 48 Vdc power supply for immediate integration into field systems.