FLAT-PAK SERIES Model FP-PA20 Audio Power Amplifier

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FLAT-PAK SERIES
Model FP-PA20
Audio Power Amplifier
ANYWHERE YOU NEED...
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20 Watts RMS Audio Power Amplifier
Output for 8 Ohm Speaker
Maximized Audio Level at Full Power Output
Superior Audio Quality at High Output Levels
Input / Output Terminal Block Connections
Line Level Balanced or Unbalanced Input
Integral Audio Compressor to Control Clipping
High Overall Audio Operating Level
Peak LED to Indicate Audio Compression
Ultra-compact All Metal Construction
 Convenience of RDL FLAT-PAKs
You Need The FP-PA20!
The FP-PA20 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 rackmounting accessories permit single or multiple FLAT-PAK module mounting.
APPLICATION: The FP-PA20 is the ideal choice in many applications where a high quality utility amplifier
is needed to drive an 8  speaker.
The FP-PA20 features a balanced line level input that may be connected unbalanced. A front panel gain
control is designed to be adjusted either manually or with a trimming screwdriver. The gain range will
accommodate standard unbalanced levels as well as professional balanced levels. The output will drive
an 8  speaker or multiple speakers connected to present an 8  load to the amplifier.
A red PEAK LED is provided to indicate the threshold of the integral compressor. Audio levels that could
cause the amplified output to clip are compressed according to two dynamic time constants. Normal
audio level signals remain unaffected by the compressor thereby preserving audio dynamics and
preventing the compressor from increasing feedback potential when the amplifier is used for paging. The
compressor is designed to remain aurally transparent while maintaining clean, unclipped amplified audio
for input overloads of up to 20 dB. The FP-PA20 produces average audio levels and audio clarity normally
expected of amplifiers delivering much higher output power.
The durable construction and low profile of the FP-PA20 allow mounting in a wide range of locations not
suited to a conventional style power amplifier. Power is provided to the module either through the barrier
block or through the DC power jack. For full RMS output power, a 24 VDC 2A power supply is required.
A 1A supply is sufficient for normal program audio levels and content. Power supplies are sold
separately.
Wherever a high quality constant voltage audio power amplifier is needed to provide reliability,
compactness and unsurpassed versatility, the FP-PA20 is the ideal choice. Use the FP-PA20 individually,
or combine it with other RDL products as part of a complete audio/video system.
RDL  659 N. 6th St.  Prescott, AZ., USA 86301  (928) 443-9391  FAX (928) 443-9392  www.rdlnet.com
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FLAT-PAK SERIES
Installation/Operation
EN55103-1 E1-E5; EN55103-2 E1-E4
Typical Performance reflects product at publication time
exclusive of EMC data, if any, supplied with product.
Specifications are subject to change without notice.
Model FP-PA20
Audio Power Amplifier
ADJUST AMPLIFIER GAIN
USE PROTECTED 24 VDC SUPPLY
1 A MINIMUM, 2 A RECOMMENDED
2 A REQUIRED FOR RMS OUTPUT PWR
POWER ON INDICATOR
GAIN
24VDC 2A
OR
P
E
A
K
+ -
INPUT
INPUT
BALANCED
LINE-LEVEL
- +
8 OUT
- +
8 OUT
-
+
+
8 OHM SPEAKER
20 WATTS RMS
PLUS COMPRESSION
PWR
+
+ -
-
24 VDC
POWER
SOURCE
20 WATTS RMS
PLUS COMPRESSION
PWR
+
UNBALANCED
LINE-LEVEL
O
N
GAIN
P
E
A
K
24VDC 2A
O
N
PEAK LED INDICATES
COMPRESSOR ACTIVITY.
ADJUST SO LED DOES NOT
FLASH CONTINUOUSLY FOR
NORMAL LEVELS.
-
-
+
8 OHM
8 OHM
-
+
8 OHM
+
8 OHM
TYPICAL PERFORMANCE
Input Impedance:
Input / Output Connectors:
Gain Adjustment:
Minimum Input Levels:
Balanced:
Unbalanced:
Maximum Input Levels:
Balanced:
Unbalanced:
Frequency Response:
THD+N:
Compressor:
Noise:
CMRR:
Output Power:
Ambient Operating Environment:
Power Requirement:
Indicators (2):
Line level
(+4 dBu nominal balanced)
(-10 dBV nominal unbalanced)
20 k balanced bridging
10 k unbalanced
Plug-in terminal block
Single turn audio taper
-26 dBu (to cross compressor threshold)
-28 dBV (to cross compressor threshold)
COMPRESSION
0 dB
-10 dB
-20 dB
+23 dBu
+15 dBV
-30 dB
35 Hz to 50 kHz (+/- 1.5 dB)*
< 0.1% (@ 1 kHz)*
-40 dB
< 0.5% (50 Hz to 20 kHz)*
Threshold 6 dB below rated output,
-40 dB
-20 dB
0 dB
automatically adjusting attack and release times
INPUT SIGNAL
<-80 dB (below 20 W RMS)
> 55 dB (50 Hz to 120 Hz)
20 W RMS into 8 
0° C to 30° C Maximum; 20° C Recommended
24 Vdc @ 2000 mA (for continuous RMS power output, Ground referenced)
24 to 33 Vdc @ 1000 mA (for normal program material with minimal compression, Ground referenced)
Red LED: PEAK LED indicates compressor activity
Green LED: Power ON
*measured at compressor threshold level equaling 4 W RMS output power
Overall Dimensions:
891-2110F
20 W
OUTPUT SIGNAL
Input:
Height:
Width:
Length:
2.30 in.
3.25 in.
6.04 in.
5.85 cm
8.26 cm
15.30 cm
Radio Design Labs Technical Support Centers
U.S.A. (800) 933-1780, (928) 778-3554; Fax: (928) 778-3506
Europe [NH Amsterdam] (++31) 20-6238 983; Fax: (++31) 20-6225-287