Overview
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.
- 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
Specifications
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)*
*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
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.
Tariff code:
8543.70.9910
RDL Three-Year Limited Warranty
Installation of these products by the Purchaser shall constitute Purchaser’s acknowledgement and acceptance of the terms and
conditions for sale and of this warranty, and shall constitute the Purchaser’s determination of the suitability of this product for the
Purchaser’s intended application. Radio Design Labs, Inc., also referred to as RDL®, warrants to the Purchaser that products
manufactured by RDL are free from defects in material and workmanship. This warranty applies to the period of three years from the date
of shipment, except for component parts or products purchased from other sources and supplied by RDL. Such component parts or
products bear only the warranty of the manufacturer thereof in effect at the time of shipment to the Purchaser. RDL will, without charge,
and after written notice has been received and acknowledged by RDL, repair an RDL product if proved to be defective according to the
usage of the trade, when such equipment is received by RDL at the location it designates with shipment costs prepaid by the Purchaser.
RDL shall not be liable for any expense whether for repairs, replacements, material, service, or otherwise, incurred by the Purchaser or
modifications made by the Purchaser to the product. No equipment shall be deemed defective if it shall fail to operate in a normal or
proper manner due to exposure to excessive moisture in the atmosphere, excessive temperature extremes, improper environmental
cleanliness, or any other environment not consistent with the principles of good engineering practice. In no event shall RDL have any
liability for consequential damage or expense directly or indirectly arising from the use of the products, or any inability to use it either
separately or in combination with other equipment or materials, or from any other cause, whether used in accordance with instructions or
not. This warranty is void if equipment is altered in any way by other than RDL. RDL products are NOT intended for use in life support
appliances, devices, or systems. Use of RDL products in such applications is done solely at the liability of the reseller/installer and/or end
user. RDL reserves the right to change design parameters and specifications at any time without notice. The performance measurements
reflect the products at the time of printing. This warranty is in lieu of all others, either expressed or implied. No representative is authorized
to assume for RDL any other liability in connection with RDL products.
