RDL FP-PA18H 18W Mono Hi-Temp Audio Amplifier

The RDL FP-PA18H 18W Mono Hi-Temp Audio Amplifier features a balanced line level input that may be connected to an unbalanced audio source. A gain control located next to the terminal block is designed to be adjusted manually or with a trimming screwdriver (not included). The gain range will accommodate standard unbalanced levels as well as professional balanced levels. The output drives one 8Ω speaker or multiple speakers connected to present an 8Ω load to the amplifier.

The class D amplifier includes an analog compressor/limiter for fidelity 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 increase the average output power. 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 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. 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 30mW of output power at 20 Hz or 5mW of output power at 20 kHz.

A blue power LED illuminates when the adapter is powered from an 24 VDC power supply. The module is equipped with both thermal and output short circuit protection. The class D output stage produces minimal heat for all levels of expected voice or music modulation. The thermal characteristics of the module case and construction permit operation over a range of 32 to 158°F. It is suitable for outdoor applications, signage, and other installations where ambient temperatures may become elevated due to limited convection.