Precision Audio and AV Interface Products

Radio Design Labs

ST-PA18 18 W Mono Audio Amplifier - 8 Ω

  • 18 Watts RMS Audio Power Amplifier
  • Output for 8 Ω Speaker
  • Maximized Audio Level at Full Power Output
  • Superior Audio Quality at High Output Levels
  • Line Level Balanced or Unbalanced Input
  • LOOP OUT to Feed Additional Amplifiers
  • Integral Audio Compressor to Control Clipping
  • High Overall Audio Operating Level
  • LED to Indicate Audio Compression
  • Overview
  • Specifications
  • Related Products
  • Accessories
  • Downloads
  • How to Buy
  • Product Series
  • Dimensions

The ST-PA18 features a balanced line level input that may be connected unbalanced. The gain control range will accommodate standard unbalanced levels as well as professional balanced levels. The module bridges the input signal. LOOP OUT terminals permit a balanced input to be fed to additional amplifier modules making the ST-PA18 an ideal component in distributed audio system design. The LOOP OUT may also be used to feed a subwoofer amplifier (see RDL ST-CX2S Subwoofer Filter). The ST-PA18 output will drive an 8 Ω speaker or multiple speakers connected to present an 8 Ω load to the amplifier and it is capable of driving 4 Ω loads. A red COMP 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 ST-PA18 produces average audio levels and audio clarity normally expected of amplifiers delivering much higher output power. The ST-PA18 operates from an external 24 VDC 1A power supply, sold separately. A POWER LED illuminates when the module is powered. The module provides thermal and output short-circuit protection.

Applications

Input:
Line level (+4 dBu bal; -10 dBV unbal)
Input Impedance:
20 kΩ balanced bridging; 10 kΩ unbal
Gain Adjustment:
Single turn
Minimum Input Levels:
-16 dBu* balanced; -18 dBV* unbalanced
Maximum Input Levels:
+25 dBu balanced; +22 dBV unbalanced
Frequency Response:
20 Hz to 20 kHz (± 2 dB)*
THD+N:
< 1%*
*measured at compressor threshold level equaling 12 W RMS output power
Noise:
< -75 dB (below 18 W RMS)
Compressor:
Threshold 3 dB below rated output, automatic adjusting attack and release
CMRR:
> 45 dB (50 Hz to 120 Hz)
Output Power:
18 W RMS into 8 Ω
Output Circuit:
Class D
Ambient Operating Environment:
0° C to 30° C Max; 20° C Recommended
Indicators (2):
Red LED: LED indicates compressor activity
Green LED: Power ON
Power Requirement:
24 Vdc @ 1000 mA, Ground referenced
Package Type:
Cardboard Box
Package Dimensions:
2 x 2 x 4 in.
Shipping Weight:
0.225 lbs.
WEEE weight:
0.165 lbs.
Tariff code:
8543.70.9910

Documents:
Format
PDF
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Press Release:
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Declaration of Conformity:
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STICK-ON SERIES

STICK-ONs are the original application-specific modules for the A/V, recording and broadcast industries. Module functions include signal detection, switching, pre-amplification, format conversion, line driving, power amplification, mixing, distribution, gain control, equalization, routing and more. Each STICK-ON is an ultra-compact module engineered to provide higher performance and longer life than other industry products. STICK-ON modules are solid encapsulated hybrid circuits in durable industrial black plastic enclosures (1.55", 3.94 cm x 3", 7.62 cm x 0.65", 1.65 cm) with clear bold white lettering for the terminal block connections, recessed trimming controls and switches.

Since RDL first originated application-specific modules, STICK-ONs have led the industry in economical, high-performance and cost-effective long life solutions in system designs. Multiple STICK-ON modules can be interconnected to form all or part of an A/V system. A single STICK-ON module may be mounted right where its function is needed, often to add an input, output, or gain adjustment to existing equipment. STICK-ON modules allow customizing an A/V system to precisely match users’ needs. Adding STICK-ONs to an existing system can extend system life by adding updated features, resulting in considerable cost savings. A complete range of backboard and rack mounting options is available for systems comprised of multiple STICK-ON modules.

The technology used in STICK-ON modules has been regularly updated over the years to insure industry-leading performance. Functions and features provided by STICK-ONs, since their introduction, are still available today. This continuity in product offering and support makes STICK-ON modules the preferred long-term resource for system design solutions. STICK-ON SERIES modules are designed and manufactured in the U.S.A.

ST-PA18 ST-PA18