Three Pair Combiner to Single Pair Sender-Twisted Pair Format-A

The RDL TX-TPSA1A is a three-pair Format-A audio combiner that uses isolated active mixing to sum sources carried on signal pairs A, B and C. The combined signal drives one selectable pair on the RJ45 OUTPUT connection. A LOOP IN connection passes the other two audio pairs and the power pair through to the output, supporting integration with additional Format-A modules.

Ideal Use Cases

This model is suited to RDL TP Format-A installations that need to combine audio from three cable pairs and place the summed result onto one designated output pair. It is particularly useful when pairs A, B and C are already carrying separate audio sources, but a downstream connection requires a combined feed. The selectable pair assignment also makes the TX-TPSA1A useful when the system design requires the combined audio to occupy pair A, B or C without replacing the module.

Why Choose This Model

The TX-TPSA1A combines three important functions in one module: isolated active mixing, selectable output-pair assignment and Format-A loop-through. Its selector switch determines whether the summed signal drives pair A, B or C on the OUTPUT jack. At the same time, two audio pairs and the power pair pass from LOOP IN to OUTPUT. Local power can feed modules connected to the RJ45 jacks, and the unit can be daisy-chained with additional Format-A senders. Studio-quality precision active balanced circuitry supports demanding audio signal paths.

Installation and Integration

Both inputs use RJ45 connections. One RDL TP Format-A input provides active summing, while the second serves as LOOP IN. The output is also RDL TP Format-A on an RJ45 connection. After connecting the appropriate Format-A feeds, set the output selector to pair A, B or C according to the required downstream pair assignment. The two pairs not selected for the summed output, together with the power pair, pass through from LOOP IN.

The module requires 24 Vdc at 65 mA plus the requirements of connected loads. Four power connections are listed: one power jack and three RJ45 connections. Recommended supplies are the PS-24AS for the USA and the PS-24AX for international use. A Power In indicator provides visible power-status reference. The specified ambient operating range is 0 degrees C to 55 degrees C.

Performance Highlights

The active balanced audio circuitry provides a frequency response of 10 Hz to 50 kHz within plus or minus 0.1 dB. THD+N is specified at less than 0.005%, while headroom exceeds 18 dB above a +4 dBu operating level. Common-mode rejection is greater than 80 dB from 50 Hz to 150 Hz. The listed noise specification below +4 dBu is less than 90 dB. Together, these figures define a wide-bandwidth, low-distortion operating profile for Format-A audio distribution.

What Makes It Different

The defining feature of the TX-TPSA1A is the way it manages all three Format-A signal pairs. It actively combines sources on pairs A, B and C, assigns the sum to a user-selected output pair, and allows the remaining two audio pairs and power pair to continue through the system. This combination of active summing, pair selection, loop-through and local power distribution supports flexible daisy-chain configurations without changing the Format-A connection standard.

The enclosure measures 3.17 inches wide by 1.76 inches high by 2.06 inches deep, equivalent to 8.05 by 4.47 by 5.23 cm. Its listed shipping weight is 0.36 lb, and its WEEE weight is 0.32 lb.

Final Assessment

The RDL TX-TPSA1A is a focused solution for combining three Format-A audio pairs into one selectable output pair while preserving the other audio pairs and power through LOOP IN. Its RJ45 connectivity, active balanced architecture, pair selector, local power feeding and daisy-chain support make it a strong fit for RDL TP Format-A systems that require precise three-to-one audio combining and controlled pair placement.