RDL FP-PA18HX 18 W Mono Class D Audio Amplifier / 8 Ohm Output / High-Temp 0-70 C / 24 V

Description

The FP-PA18HX is a compact 18 W mono Class D audio amplifier designed to deliver clear amplified audio into an 8 Ohm load. It is engineered for elevated ambient temperatures up to 70 C and includes a worldwide 24 Vdc power supply for flexible deployment. The unit is packaged in an ultracompact all metal enclosure for durability.

Key features include a balanced line level input that accepts unbalanced connections, a single-turn gain adjustment, and detachable terminal block connections for input and output. An analog compressor/limiter minimizes clipping and increases average output power while preserving normal dynamic behavior for standard program material. LED indicators provide immediate visual status for power, output activity, and compression activity.

Performance specifications include 18 W RMS into 8 Ohm, frequency response of 20 Hz to 20 kHz (+/ 1 dB) measured at compressor threshold, and THD+N under 0.5 percent across the audio band at the referenced level. The compressor threshold is set 3 dB below rated output and the detector circuitry senses output activity down to milliwatt levels. Thermal and short circuit protection are integrated to maintain reliable operation.

Connectivity is handled via detachable terminal blocks for both balanced/unbalanced line input and speaker output, and the module accepts a 24 Vdc supply provided by the included worldwide power module. The output stage provides an open collector output tied to the output detector for system-level control or monitoring. The gain control accommodates both consumer and professional nominal input levels.

The FP-PA18HX is suited to applications such as outdoor signage audio, distributed paging feed, and compact PA systems where elevated ambient temperatures limit conventional amplifier choices. Its analog compression provides improved average loudness and clarity compared to typical class D designs that rely on digital limiting. The compact footprint allows installation in confined equipment racks or enclosures where space is limited.

Installation is straightforward using the detachable terminal blocks and single-turn gain control that can be adjusted manually or via a trimming screwdriver. The high efficiency Class D design minimizes heat generation while the high-temperature internal components permit continuous operation up to 70 C. The unit ships in a cardboard box and is ready for integration into broader AV systems.