RDL TX-PA40D 40W Stereo Audio Amplifier - 8 Ohm

Description
Warranty Information

Overview

The TX-PA40D is the ideal choice in many applications where a high quality, high-efficiency utility amplifier is needed to drive a pair of 4 Ω or 8 Ω speakers. It is specifically suited to fixed-gain amplification applications where gain is controlled by other equipment. Examples include projectors with variable audio outputs used in classrooms, boardrooms and video conferencing.

The TX-PA40D features two unbalanced line level inputs on high-reliability gold plated phono (RCA) jacks. A front-panel recessed gain control trimmer permits setting the desired amplifier output level for each channel. The gain range accommodates the range of typical unbalanced audio signal levels. Each of the two TX-PA40D outputs will drive a 4 Ω or 8 Ω speaker or multiple speakers connected to present a 4 Ω or 8 Ω load to the amplifier. The output impedance is switch-selectable on the front panel of the module.

A front-panel switch is provided to sum the audio inputs to mono. In the STEREO mode, the TX-PA40D independently amplifies each audio channel, left (L) and right (R). If speaker placement in the specified installation is incompatible with stereophonic amplification, the INPUT MODE switch may be set to SUMMED MONO.

The TX-PA40D includes a stereo analog compressor/limiter for audio fidelity noticeably superior to conventional class D amplifiers with digital limiting. The input GAIN settings determine 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 40 W amplifier. A red front-panel 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 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 TX-PA40D, with compression, is capable of producing average audio output levels and clarity normally expected from stereo amplifiers with a much higher output power rating.

A blue POWER LED illuminates when the TX-PA40D 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 stages produce minimal heat for all levels of expected voice or music modulation. Continuous full-power operation with audio tones will not damage the amplifier, but is not recommended.

Wherever an ultra-compact, high quality, high efficiency audio power amplifier is needed to provide reliability and unsurpassed versatility, the TX-PA40D is the ideal choice. Use the TX-PA40D individually, or combine it with other RDL products as part of a complete audio/video system.

Features:

Stereo Audio Power Amplifier
20 Watts RMS per Channel into 8 Ω - 40 Watts Total
15 Watts RMS per Channel into 4 Ω - 30 Watts Total
Left and Right Unbalanced Phono Jack Inputs
Switch-Selectable Stereo or Mono Operation
Studio Quality, Aurally Transparent Compressor/Limiter
Compressor/Limiter Controls Clipping
Compressor Produces Maximized Average Output Power
Compression Enabled Using Input Level Adjustments
LED to Indicate Audio Compression Threshold
Outputs Drive 4 or 8 Ohm Speakers
High-Efficiency Class D Operation
Thermal and Short-Circuit Protection
TX-PA40D includes North American Cord; TX-PA40DE excludes Power Cord

Specifications

Inputs (2):

Line level (-10 dBV nominal unbalanced), Left and Right

Input Impedance:

10 kΩ unbalanced

Gain Adjustments (2):

Single turn, one per channel

Minimum Input Levels:

-18 dBV (to cross compressor threshold)

Maximum Input Levels:

+15 dBV

Frequency Response:

20 Hz to 20 kHz (± 1 dB, 4 or 8 Ohms)*

THD+N:

< 0.1% (1 kHz, 1 W, 4 or 8 Ohms); < 1% (50 Hz to 20 kHz, 8 Ohms)*
*measured at compressor threshold level equaling 12 W RMS (8 Ohms) output power

Compressor:

Threshold nominally 2 dB below rated output, automatically adjusting attack and release times

Crosstalk:

Better than 60 dB (1 kHz, no compression)

Noise:

< -75 dB (below 20 W RMS)

Selectors:

Slide switches: Output Impedance 4 Ohms or 8 Ohms; Input Mode SUMMED MONO or STEREO

Output Power:

20 W RMS into 8 Ω per channel, 40 W RMS total; 15 W RMS into 4 Ω per channel, 30 W RMS total

Output Circuit:

Class D

Ambient Operating Environment:

0° C to 40° C Maximum; 20° C Recommended

Indicators (2):

Red LED: THRESHOLD LED indicates compressor activity
Blue LED: POWER on

Power Requirement (Supply Included):

Input: 100 to 240 VAC, 50 to 60 Hz, 1.5 A, IEC C14; Output to module: 24 Vdc

Package Type:

Cardboard Box

Package Dimensions:

5.125 x 2.5 x 5.875 in.

Shipping Weight:

1.655 lbs.

WEEE weight:

1.525 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.