FLAT-PAK
™
SERIES
Model
FP-PA18
18 W Audio Power Amplifier with Power Supply
18 Watts RMS into 8
Automatic Energy-Saving Sleep Mode
Selectable Sleep Delay: Off, 5, 15, 25 Minutes
Input / Output Detachable Terminal Block Connections
Line Level Balanced or Unbalanced Input
Compressor/Limiter Controls Clipping
LED to Indicate Audio Compression Threshold
Compressor Produces Maximized Average Output Power
Audio Quality Superior to Standard Amplifiers
Ultra-compact All Metal Construction
High-Efficiency Class D Operation
Thermal and Short-Circuit Protection
The FP-PA18 is part of the group of versatile FLAT-PAK products from Radio Design Labs. The unique FLAT-PAK case can be directly screwed
or bolted to cabinets or shelves. Optionally available rack-mounting accessories permit single or multiple FLAT-PAK module mounting.
APPLICATION:
The FP-PA18 is a high efficiency 18 W power amplifier with a line input, 8 ohm output, integral audio
compressor and an automatic sleep mode. The FP-PA18 features a balanced line level input that may be connected unbalanced.
A gain control located next to the terminal block is designed to be adjusted manually or with a trimming screwdriver. The gain
range will accommodate standard unbalanced levels as well as professional balanced levels. The output drives one 8 ohm
speaker or multiple speakers connected to present an 8 ohm load to the amplifier.
The FP-PA18 includes an analog compressor/limiter for fidelity audibly superior to conventional class D amplifiers 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 substantially increase the average output power beyond that of a standard 18 W amplifier. 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 FP-PA18, with compression, is capable
of producing average audio output levels and clarity normally expected from amplifiers with a much higher output power rating.
The FP-PA18 circuits are all designed for low power consumption. In the absence of an audio input, a digital timer is enabled to
switch the class D output stage off. When this sleep mode is active, the amplifier module and its included RDL power supply
consume less than 1 W of mains power. A control on the end plate sets the sleep mode delay timer to 5, 15 or 25 minutes. The
control also permits the installer to bypass the sleep mode to conform to system specifications that require the amplifier to be
active at all times. Upon detection of an input signal, the amplifier is nearly inaudibly and instantly restored to full operation within
150 milliseconds.
The output stage includes an audio detector that illuminates the green
OUTPUT ACTIVE
LED and provides an active open
collector output when amplified audio is present at the module output. 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 30 mW of output power at
20
Hz or 5 mW of output power at 20 kHz.
A blue
POWER
LED illuminates when the FP-PA18 is powered from its external 24 Vdc power supply. The power LED is dimly
illuminated when the sleep mode disables the amplifier and glows brightly when the amplifier operation is fully enabled. The
module is equipped with both thermal and output short-circuit protection. The high-efficiency Class D output stage produces
minimal heat for all levels of expected voice or music modulation.
Wherever an ultra-compact, high quality, high efficiency eco-friendly audio power amplifier is needed to provide reliability and
unsurpassed versatility, the FP-PA18 is the ideal choice. Use the FP-PA18 individually, or combine it with other RDL products as
part of a complete audio/video system.
RDL
659 6
th
St.
Prescott, AZ., USA 86301
(928) 443-9391
FAX (928) 443-9392
www.rdlnet.com