The TX-TPS6A is a single-pair audio sending module compatible with RDL Format-A twisted pair products. One low-impedance +4 dBu balanced line-level audio source connects to the module using the detachable terminal block. A studio-quality transformer provides isolation between the audio source and the RJ45 OUTPUT. The TX-TPS6A 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-TPS6A 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-TPS6A is a passive module that does not require power to operate. If power is present on a cable connected to the LOOP IN jack, that power is passed through to the modules connected to the OUTPUT jack.