The TX-TPS1A is a single-pair audio sending module compatible with RDL Format-A twisted pair products. One line-level source may be connected to the module using either the -10 dBV unbalanced RCA phono jack or the +4 dBu balanced detachable terminal block. A studio-quality buffer amplifier feeds the RJ45 OUTPUT at the correct operating level. The TX-TPS1A is a single-pair sender, feeding the input signal to the cable pair set on the front-panel switch during installation. This module drives only one cable pair, therefore a LOOP IN RJ45 jack is provided to accept signals and power from other mic-level or line-level Format-A senders. Two other single-pair senders may be chained to the LOOP IN jack, or a single two-pair sender may be connected. If three single-pair senders are connected together, each sender must feed a different pair: A, B or C. The TX-TPS1A must be set to feed pair A if it is connected together with an RDL two-pair sender that feeds stereo audio on pairs B and C. The TX-TPS1A may be powered directly from a 24 Vdc power supply using either the power jack or the detachable terminal block. Local power connected to the module is also fed to all modules connected to the LOOP IN and OUTPUT RJ45 jacks. The TX-TPS1A may be remotely powered through the twisted pair cable from any other module, signal distributor or RDL power inserter connected to the same twisted pair cable. Module power is indicated by a front-panel LED.