Radio Design Labs TX-PA40D
20W RMS Per Channel @ 8 Ohms Stereo Amplifier with Power Supply

OUR PART #  TX-PA40D


Radio Design Labs' 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 Ohm or 8 Ohm speaker or multiple speakers connected to present a 4 Ohms or 8 Ohms 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.

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 Ohm or 8 Ohm speakers. It is designed for 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.

Radio Design Labs TX-PA40D Features:

  • Stereo Audio Power Amplifier
  • 20 Watts RMS per Channel into 8 Ohms – 40 Watts Total
  • 15 Watts RMS per Channel into 4 Ohms – 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 Power Cord

Radio Design Labs TX-PA40D Specifications:

  • Inputs (2): Line level (-10 dBV nominal unbalanced), Left and Right
  • Input Impedance: 10 kOhms 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 12W 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 Ohms per channel,40 W RMS total; 15 W RMS into 4 Ohms 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"
  • Shipping Weight: 1.655 lbs.
24VDC, 2A Universal Power Supply with North American Plug-End Cord
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Radio Design Labs' PS24V2A is a 24 volt DC Switching Power Supply, with North American cord, 2 Amp output and DC Plug.Radio Design Labs PS24V2A Specifications: Input: 100 to 240 VACOutput: 24 Vdc, 2 A (UL, ...
Mounting Kit for STICK-ON, TX, or Rack-Up module
Radio Design Labs MB1-RDL Mounting Kit for STICK-ON, TX, or Rack-Up module
Two mounting brackets mounts a STICK-ON, TX, or Rack-Up module to a flat surface.
Mounting Frame for Stick/TX
Radio Design Labs SR-4 Mounting Frame for Stick/TX
Radio Design Labs' SR-4 is a universal module chassis that can mount to a backboard, wall or nearly any other support. It provides mounting for 4 STICK-ON power amplifiers or 7 standard STICK-ON modules. TX ™ modules may also be mounted. ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
Pole Mount Tray for RDL Module
Radio Design Labs PM-1T Pole Mount Tray for RDL Module
The PM-1T is a tray that mounts above a projector using a standard (1.5" I.D.) round projector pole or any smaller round or rectangular pole. The tray accommodates up to two FP-PA20 Audio Power Amplifiers (for stereo operation) and two ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
1RU Rack Adapter for TX Series Products
Radio Design Labs TX-RA5 1RU Rack Adapter for TX Series Products
Radio Design Labs' TX-RA5 chassis is a single rack unit accessory which provides mounting for up to 5 TX Series products.

Usually ships in 7-14 business days.
Need it sooner? Call us!
10.4" Rack Mount for 3 TX Series Products
Radio Design Labs TX-HRA3 Rack Mount 10.4" Rack Mount for 3 TX Series Products
The TX-HRA3 rack mounts 3 TX modules. This adapter fits 10.4" racks.Radio Design Labs TX-HRA3 Rack Mount Specifications: Package Dimensions (LxWxD): 13" X 2.5" X 2.5" Shipping Weight: 0.55 lbs.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Din Rail Adaptor for TX Module
Radio Design Labs DRA-35T Din Rail Adaptor for TX Module
The DRA-35T provides mounting for any RDL® TX or MAX TX module to a DIN rail. The unique design allows mounting TX modules in a rack, cabinet or anywhere else DIN rail mounting of TX modules is desired.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Kit to Mount ST, TX Series Modules on FP Panel
Radio Design Labs MB3-RDL Kit to Mount ST, TX Series Modules on FP Panel
TX or STICK-ON Module fastens to MB-3 which slides into FP-RRA/H track.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Kit for RU and TX Series
Radio Design Labs MB2-RDL Mounting Kit for RU and TX Series
MB-2 pair mounts a RACK-UP or TX module above or below a surface.

Usually ships in 7-14 business days.
Need it sooner? Call us!

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Radio Design Labs TX-PA40D
20W RMS Per Channel @ 8 Ohms Stereo Amplifier with Power Supply

OUR PART #  TX-PA40D

Product Information:

Radio Design Labs' 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 Ohm or 8 Ohm speaker or multiple speakers connected to present a 4 Ohms or 8 Ohms 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.

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 Ohm or 8 Ohm speakers. It is designed for 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.

Radio Design Labs TX-PA40D Features:

  • Stereo Audio Power Amplifier
  • 20 Watts RMS per Channel into 8 Ohms – 40 Watts Total
  • 15 Watts RMS per Channel into 4 Ohms – 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 Power Cord

Radio Design Labs TX-PA40D Specifications:

  • Inputs (2): Line level (-10 dBV nominal unbalanced), Left and Right
  • Input Impedance: 10 kOhms 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 12W 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 Ohms per channel,40 W RMS total; 15 W RMS into 4 Ohms 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"
  • Shipping Weight: 1.655 lbs.
24VDC, 2A Universal Power Supply with North American Plug-End Cord
Radio Design Labs PS24V2A 24VDC, 2A Universal Power Supply with North American Plug-End Cord
Radio Design Labs' PS24V2A is a 24 volt DC Switching Power Supply, with North American cord, 2 Amp output and DC Plug.Radio Design Labs PS24V2A Specifications: Input: 100 to 240 VACOutput: 24 Vdc, 2 A (UL, ...
Mounting Kit for STICK-ON, TX, or Rack-Up module
Radio Design Labs MB1-RDL Mounting Kit for STICK-ON, TX, or Rack-Up module
Two mounting brackets mounts a STICK-ON, TX, or Rack-Up module to a flat surface.
Mounting Frame for Stick/TX
Radio Design Labs SR-4 Mounting Frame for Stick/TX
Radio Design Labs' SR-4 is a universal module chassis that can mount to a backboard, wall or nearly any other support. It provides mounting for 4 STICK-ON power amplifiers or 7 standard STICK-ON modules. TX ™ modules may also be mounted. ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
Pole Mount Tray for RDL Module
Radio Design Labs PM-1T Pole Mount Tray for RDL Module
The PM-1T is a tray that mounts above a projector using a standard (1.5" I.D.) round projector pole or any smaller round or rectangular pole. The tray accommodates up to two FP-PA20 Audio Power Amplifiers (for stereo operation) and two ...

Usually ships in 7-14 business days.
Need it sooner? Call us!
1RU Rack Adapter for TX Series Products
Radio Design Labs TX-RA5 1RU Rack Adapter for TX Series Products
Radio Design Labs' TX-RA5 chassis is a single rack unit accessory which provides mounting for up to 5 TX Series products.

Usually ships in 7-14 business days.
Need it sooner? Call us!
10.4" Rack Mount for 3 TX Series Products
Radio Design Labs TX-HRA3 Rack Mount 10.4" Rack Mount for 3 TX Series Products
The TX-HRA3 rack mounts 3 TX modules. This adapter fits 10.4" racks.Radio Design Labs TX-HRA3 Rack Mount Specifications: Package Dimensions (LxWxD): 13" X 2.5" X 2.5" Shipping Weight: 0.55 lbs.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Din Rail Adaptor for TX Module
Radio Design Labs DRA-35T Din Rail Adaptor for TX Module
The DRA-35T provides mounting for any RDL® TX or MAX TX module to a DIN rail. The unique design allows mounting TX modules in a rack, cabinet or anywhere else DIN rail mounting of TX modules is desired.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Kit to Mount ST, TX Series Modules on FP Panel
Radio Design Labs MB3-RDL Kit to Mount ST, TX Series Modules on FP Panel
TX or STICK-ON Module fastens to MB-3 which slides into FP-RRA/H track.

Usually ships in 7-14 business days.
Need it sooner? Call us!
Mounting Kit for RU and TX Series
Radio Design Labs MB2-RDL Mounting Kit for RU and TX Series
MB-2 pair mounts a RACK-UP or TX module above or below a surface.

Usually ships in 7-14 business days.
Need it sooner? Call us!

Click to download

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