Active Two-Pair Sender-Twisted Pair Format-A-XLR Microphone & Stereo RCA In

The RDL D-TPSL2A is an active two-pair Format-A sender that combines one balanced XLR microphone input with two unbalanced RCA line inputs. Its microphone signal feeds Format-A pair A, while the left and right line inputs are summed to mono and routed to pair B. Studio-quality precision active balanced circuitry, selectable microphone gain, IEC 24 Vdc phantom power, and flexible local or remote powering support dependable audio integration.

Ideal Use Cases

This model is suited to installations that need microphone and consumer-level line audio connected at the same input location. The balanced microphone input accommodates levels from -45 to -65 dBu, while the two RCA phono inputs accept nominal -10 dBV left and right signals. Because the microphone and summed line source occupy separate Format-A pairs, both can be transported through compatible RDL TP Format-A infrastructure without requiring separate sender modules.

The summed line path is especially useful when a stereo RCA source must be delivered as a mono feed. Pair A remains dedicated to the microphone, and pair B carries the combined left and right line inputs.

Why Choose This Model

The D-TPSL2A provides three physical inputs in a compact module: one 1.2 kΩ balanced microphone input and two 10 kΩ unbalanced line inputs. The rear-panel gain switch allows the microphone stage to be configured for 50 dB NORM gain or 63 dB HIGH gain. This gives the installer a defined choice for accommodating the specified microphone input range.

IEC 24 Vdc phantom power is available at the microphone input. The active balanced circuitry provides more than 18 dB of headroom above +4 dBu, while the integrated microphone low-cut filter is specified at -10 dB at 30 Hz. A blue power LED provides visible confirmation that the module is powered.

Installation and Integration

The module connects to an RDL TP Format-A system through an RJ45 output and uses two signal pairs. Pair A carries the microphone signal; pair B carries the left and right RCA inputs summed to mono. Power can be received remotely through the twisted-pair cable or connected locally through the detachable terminal block. When local power is used, its fused feed powers connected modules.

The D-TPSL2A requires 24 Vdc at 65 mA plus the requirements of connected loads. Recommended power supplies, which are not included, are the PS-24AS for the USA and PS-24AX for international use. The module measures 1.6 inches wide, 4.11 inches high, and 1.89 inches deep. A mounting box with a minimum depth of 2.4 inches is required. The specified ambient operating range is 0° C to 55° C.

Performance Highlights

The microphone path has a frequency response of 100 Hz to 30 kHz within ±1 dB. Its THD+N is below 0.1% from 80 Hz to 20 kHz. Noise below +4 dBu is specified at less than -80 dB in NORM gain and less than -70 dB in HIGH gain. Microphone CMRR is greater than 60 dB in HIGH gain and greater than 65 dB in NORM gain from 50 Hz to 150 Hz.

The line path provides 12 dB of gain and a frequency response of 20 Hz to 50 kHz within ±0.5 dB. Line THD+N is below 0.05% from 20 Hz to 50 kHz, and line noise below +4 dBu is specified at less than -95 dB. The RCA inputs accept a maximum level of +8 dBV.

What Makes It Different

The defining feature is its deliberate two-pair signal arrangement. Instead of treating the RCA connectors as two independently transported channels, the D-TPSL2A combines them into one mono line feed on pair B while reserving pair A for the microphone. This configuration joins balanced microphone input, phantom power, selectable gain, stereo-to-mono line summing, Format-A transport, and power distribution in one compact sender.

Its two powering methods also support different system layouts. Remote power can arrive through the twisted-pair connection, while the terminal-block input provides a local-power option with a fused feed for connected modules.

Final Assessment

The RDL D-TPSL2A is a focused solution for transporting one microphone source and one summed RCA line source over two Format-A pairs. Its balanced XLR input, IEC phantom power, 50 or 63 dB microphone gain, wide line-path frequency response, RJ45 output, and local or remote power capability provide a clearly defined feature set for RDL TP Format-A audio systems.