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

The RDL DS-TPSL2A is an active two-pair Format-A sender that combines one balanced XLR microphone input with two unbalanced RCA line inputs. The microphone signal feeds Format-A Pair A, while the left and right RCA inputs are summed to mono and routed through Pair B. Studio-quality precision active balanced circuitry, selectable microphone gain, phantom power, remote powering, and local power distribution support efficient integration into twisted-pair audio systems.

Ideal Use Cases

This model is suited to fixed audio installations that need to place a microphone and a stereo source at one input location and carry both through a single Format-A connection. The balanced microphone input accommodates signals from -45 to -65 dBu and provides IEC 24 Vdc phantom power. Two RCA phono inputs accept unbalanced -10 dBV line-level audio, making the sender appropriate where a microphone must share an installed audio path with a left-and-right line source.

The DS-TPSL2A uses two Format-A signal pairs without keeping the line channels separate: the microphone occupies Pair A, and the left and right line inputs are summed to mono on Pair B. This routing should be considered when the connected system requires a combined line feed rather than discrete stereo transmission.

Why Choose This Model

The rear-panel gain switch provides a practical choice between 50 dB NORM gain and 63 dB HIGH gain for the microphone input. This allows the input stage to accommodate the specified microphone level range while preserving a straightforward installed configuration. The line input path supplies 12 dB of gain and supports a maximum input level of +8 dBV.

Power can arrive remotely through the twisted-pair cable or locally through the detachable terminal block. When local power is used, a fused feed powers all connected modules. A blue power indicator provides visible confirmation that the module is powered. Recommended supplies, sold separately, are the PS-24AS for the USA and PS-24AX for international use.

Installation and Integration

The microphone connects through XLR, while the left and right line sources connect through RCA phono jacks. The outgoing RDL TP Format-A signal uses an RJ45 connection. Two power connection methods are provided: the RJ45 interface and a detachable terminal block for local 24 Vdc input. The stated power requirement is 24 Vdc at 65 mA plus the requirements of connected loads.

The unit measures 1.6 inches wide by 4.11 inches high by 1.89 inches deep, equivalent to 4.06 by 10.45 by 4.8 cm. Installation requires a mounting box with a minimum depth of 2.4 inches, or 6.1 cm. Its specified ambient operating range is 0 degrees C to 55 degrees C. The stainless model designation identifies this version within the DS-TPSL2A product configuration.

Performance Highlights

The microphone channel has a frequency response of 100 Hz to 30 kHz within +/-1 dB and includes an integral low-cut filter rated at -10 dB at 30 Hz. Its THD+N is less than 0.1% from 80 Hz to 20 kHz. Noise below +4 dBu is 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 extends from 20 Hz to 50 kHz within +/-0.5 dB, with THD+N below 0.05% across that range and noise below +4 dBu of less than -95 dB. Available headroom above +4 dBu is greater than 18 dB. Specified line-to-line crosstalk is less than 90 dB at 1 kHz and less than 75 dB from 20 Hz to 20 kHz.

What Makes It Different

The DS-TPSL2A consolidates three physical inputs into two defined Format-A signal pairs. Unlike a sender that transports only a microphone or only line audio, it assigns the balanced microphone directly to Pair A and creates a mono line feed from the two RCA inputs for Pair B. The combination of rear-panel gain selection, microphone phantom power, an integral low-cut filter, remote powering, and fused local power distribution gives installers several useful functions within one active sender.

Final Assessment

For an RDL TP Format-A system requiring a balanced XLR microphone input and a combined feed from two -10 dBV RCA sources, the DS-TPSL2A provides clearly defined routing and documented audio performance. Its dual powering options, selectable microphone gain, RJ45 output, compact dimensions, and power indicator make it a focused integration component. The design is best selected when a mono sum of the left and right line inputs on Pair B matches the intended system architecture.