RDL FP-PA18H Datasheet

FLAT-PAK™ SERIES

Model FP-PA18H

18 W Audio Power Amplifier with Power Supply

 18 Watts RMS into 8 
 Operation in Elevated Ambient Temperatures to 70°C
 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-PA18H 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:

capable of operation in a high ambient temperature environment. The thermal characteristics of the module case and construction
throughout using high temperature components permit operation over a range of 0 to 70 degrees C. The FP-PA18H is ideally
suited to outdoor applications, signage and other installations where ambient temperatures may become elevated due to limited
convection.

(Note: The power supply must be mounted in a location with a maximum ambient temperature of 40 degrees C. The FP-PA18H
module is available separately for installation with a high temperature power supply or in systems with distributed 24 Vdc power.
Contact RDL technical support for more details.)

The FP-PA18H 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-PA18H 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-PA18H, with compression, is
capable of producing average audio output levels and clarity normally expected from amplifiers with a much higher output power
rating.

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 and 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-PA18H is powered from its external 24 Vdc power supply. 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 audio power amplifier is needed to provide reliability and unsurpassed
versatility, the FP-PA18H is the ideal choice. Use the FP-PA18H individually, or combine it with other RDL products as part of a
complete audio/video system.

The FP-PA18H is a high efficiency 18 W power amplifier with a line input, 8 ohm output and audio compressor

RDL  659 6th St.  Prescott, AZ., USA 86301  [phone]  FAX [phone]  www.rdlnet.com

FLAT-PAK

Model FP-PA18H

18 W Audio Power Amplifier with Power Supply

Mounting
The FP-PA18H should be mounted in a location with the best possible ventilation. If the module is mounted inside a box that does not provide ventilation, the amplifier
should be secured to an exterior surface of the box. The ambient operating environment must not exceed 70 degrees C. (Note: The power supply must be mounted
in a location with a maximum ambient temperature of 40 degrees C. The FP-PA18H module is available separately for installation with a high temperature power
supply or in systems with distributed 24 Vdc power. Contact RDL technical support for more details.)

™

SERIES

Installation/Operation

Declaration of Conformity available from rdlnet.com.

Sole EMC specifications provided on product package.

Specifications are subject to change without notice.

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+

-

+

AUDIO

-

INPUT

+

8 OUTPUT

Ω

-

+

POWER

OUTPUT PRESENT

O/C

18 WATTS RMS

PLUS COMPRESSION

HIGH TEMPERATURE

DO NOT GROUND

OUTPUT TERMINALS

24VDC 1A

UNBALANCED

LINE-LEVEL

8 OHM SPEAKER

BALANCED

LINE-LEVEL

OR

ADJUST AMPLIFIER GAIN

THE O/C TERMINAL IS PULLED TO
GROUND WHEN AN AUDIO SIGNAL IS
PRESENT AT THE AMPLIFIER OUTPUT.
CONNECT THE TERMINAL TO AN
INDICATOR OR TO THE LOGIC INPUT OF
OTHER EQUIPMENT (GROUND TERMINALS
MUST BE CONNECTED BETWEEN THE
OTHER EQUIPMENT AND THE MODULE).
THE O/C TERMINAL MAY BE USED TO
VERIFY THE OPERATION OF THE FP-PA18H
OR TO SWITCH ON OTHER EQUIPMENT
BASED ON PRESENCE OF AUDIO SIGNAL.

GAIN

PWR

COMPRESSION LED INDICATES
COMPRESSOR ACTIVITY. ADJUST SO
LED DOES NOT FLASH CONTINUOUSLY
FOR NORMAL LEVELS.

OUTPUT PRESENTCOMPRESSION

TYPICAL PERFORMANCE

Input: Line level (+4 dBu nominal balanced;

-10 dBV nominal unbalanced)
Input Impedance: 10 k balanced bridging; 5 k unbalanced
Gain Adjustment: Single turn audio taper
Minimum Input Levels:
Balanced: ………………-18 dBu (to cross compressor threshold)
Unbalanced: …………...-20 dBV (to cross compressor threshold)
Maximum Input Levels:
Balanced: ………………+23 dBu
Unbalanced: …………...+21 dBV
Frequency Response: 20 Hz to 20 kHz (+/- 1 dB)*
THD+N: < 0.5% (20 Hz to 20 kHz)*
Compressor: Threshold 3 dB below rated output, automatically adjusting attack and release times
CMRR: > 45 dB (50 Hz to 3 kHz)
Noise: < -72 dB (below 18 W RMS, +4 dBu input)
Output Power: 18 W RMS into 8 
Output Circuit: Class D
Output Signal Detector Threshold: 30 mW @ 20 Hz; 20 mW @ 30 Hz; 10 mW @ 50 Hz;
5 mW @ 65 Hz through 20 kHz
Output Signal Detector Output: Open collector, 5 mA
Ambient Operating Environment:
Indicators (3): Red LED: COMP LED indicates compressor activity
Green LED: OUTPUT ACTIVE (controlled by output signal detector)
Blue LED: POWER on
24 Vdc power supply current: 80 mA (idle), 975 mA (max.), Ground-referenced
Power Supply (included): 100 to 240 Vac, 50-60 Hz, 1A max.; 24 Vdc output to module
Dimensions: Height: 1.15 in.(2.92 cm); Widt h: 3.25 in.(8.26 cm); Length: 3 in.(7.62 cm)

*measured at compressor threshold level equaling 12 W RMS output power

0° C to 70° C Maximum

REGULATED

24 VDC POWER

SUPPLY ONLY

POWER INDICATOR
ILLUMINATED = ON

THE 'OUTPUT PRESENT' LED
INDICATES AUDIO IS PRESENT AT
THE AMPLIFIER OUTPUT AND THE
OPEN COLLECTOR (O/C) TERMINAL
IS PULLED TO GROUND.

NOTE: This equipment has been tested and found to
comply with the limits for a Class B digital device, pursuant
to part 15 of the FCC Rule. These limits ar e designed to
provide reasonable protection against harmful interfer ence
in a residential installation. The equipment generates,
uses and can radiate radio frequency energy and, if not
installed and used in accordance with the instructions,
may cause harmful interference to radio communications .
However, there is no guarantee that interference will not
occur in a particular installation. If this equipment does
cause harmful interference to radio or televis ion reception,
which can be determined by turning the equipment off an
on, the user is encouraged to try to correct the
interference by one or more of the following measures:

 Reorient or relocate the receiving antenna
 Increase the separation between the equipment

and receiver

 Connect the equipment into an outlet on a circuit

different from that which the receiver is
connected.

 Consult the dealer or an experienced radio/TV

technician for help.

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Radio Design Labs Technical Support Centers

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891-2160B

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