Three Input Format-A Source Selector

The RDL D-TPRX3A is a three-input source selector designed to select among sources carried on RDL Format-A signal pairs A, B, and C. Three momentary front-panel pushbuttons provide one-button access to each input, while three indicators identify the selected channel. The unit converts the chosen source to a nominal +4 dBu, 150-ohm balanced line-level output through a detachable terminal block.

Ideal Use Cases

This model is suited to audio systems that distribute three selectable sources over a single Format-A connection. It provides a dedicated selection point wherever users need direct access to sources assigned to pairs A, B, and C. Its balanced output makes it appropriate for integration with line-level audio equipment, while the RJ45 loop-through allows the Format-A connection to continue to another compatible module. Available stainless-steel, black, and white versions support different installation finishes.

Why Choose This Model

The D-TPRX3A combines simple operation with clearly specified audio performance. Each source has its own momentary pushbutton, eliminating the need to cycle through inputs. A corresponding front-panel indicator shows the selected channel. The display remains bright during adjustment and dims afterward, retaining channel indication without maintaining full adjustment brightness.

Studio-quality precision active balanced circuitry supports a frequency response of 10 Hz to 20 kHz within ±0.5 dB. Specified performance also includes greater than 18 dB of headroom above +4 dBu, THD+N below 0.005% at 1 kHz, and CMRR greater than 80 dB from 50 Hz to 150 Hz. All-metal construction provides a substantial enclosure for fixed installation.

Installation and Integration

The Format-A input uses an RJ45 connection and receives signal pairs A, B, and C. A second RJ45 connection provides Format-A loop-through. The selected audio source is delivered at a nominal +4 dBu through a detachable terminal block as a 150-ohm balanced output.

Power can arrive remotely through the twisted-pair cable or locally through a detachable terminal block. The unit requires 24 Vdc at 45 mA plus the requirements of connected loads. Its fused local power feed can supply connected modules. The listed recommended power supplies are the PS-24AS for the USA and PS-24AX for international use.

The selector measures 1.6 inches wide, 4.11 inches high, and 1.89 inches deep, equivalent to 4.06 by 10.45 by 4.8 centimeters. Installation requires a mounting box with a minimum depth of 2.4 inches. The specified ambient operating range is 0°C to 55°C.

Performance Highlights

• Three Format-A source pairs: A, B, and C
• Three momentary pushbuttons, with one button assigned to each input
• Three front-panel indicators showing the selected channel
• 10 Hz to 20 kHz frequency response within ±0.5 dB
• Greater than 18 dB headroom above +4 dBu
• THD+N below 0.005% at 1 kHz
• Noise below +4 dBu specified at less than -85 dB
• CMRR greater than 80 dB from 50 Hz to 150 Hz
• Nominal +4 dBu, 150-ohm balanced output

What Makes It Different

The D-TPRX3A handles source selection, balanced audio output, Format-A loop-through, and power distribution in one compact module. Its three dedicated controls give each Format-A pair a permanent physical selection point. Remote powering reduces the need for a separate supply connection at the selector, while the local terminal-block input remains available when local power is preferred. The fused local feed also allows that power source to serve connected modules.

Final Assessment

For an RDL Format-A system requiring selection among three source pairs, the D-TPRX3A offers direct controls, visible channel status, balanced line-level output, and flexible powering. Its RJ45 input and loop-through simplify Format-A integration, while the detachable output and power terminals support fixed wiring. The published frequency response, headroom, distortion, noise, and common-mode rejection specifications make its audio capabilities clear before installation.