The DS-TPS1A modules are single-pair audio sending modules compatible with RDL Format-A twisted pair products. These modules are designed to be mounted in wall boxes, cabinets or other enclosures that allow users to connect audio sources. The D- and DS- models mount in RDL WB-1U and WB-2U wall boxes, or in standard U.S. electrical boxes. The D-TPS1A features a white front-panel laminate with gray lettering that matches RDL Decora©-style remote controls. The DS-TPS1A is constructed of stainless steel to coordinate with RDL Decora-style stainless steel remote controls in commercial/industrial installations. The AF-TPS1A is an APPFLEX series product that is compatible with various APPFLEX wall-mount, cabinet-mount and tabletop enclosures. The EM-TPS1A is a 45mm square module that fits the European Modular mounting frames and cover plates. European electrical boxes are not sufficiently deep to accommodate RJ45 jacks and plugs, therefore the EM- products connect to the twisted pair cable through a detachable terminal block. The -TPS1A modules feature an XLR microphone input. The module provides IEC 24 V phantom and accepts input signals from both dynamic and condenser microphones. The input signal is amplified using a studio-quality microphone preamplifier optimized for normal operating levels. The rear-panel GAIN switch is normally set by the installer for NORM (normal) gain. If consistently low mic levels are expected, this switch may be set to the HIGH gain position. The pre-amplified microphone source is routed to one output cable pair selected during installation using a rear-panel switch. These modules drive only one cable pair, therefore they accept signals and power from other mic-level or line-level Format-A senders. The D-, DS-, and AF- modules have a second RJ45 jack for these input cables. Installers simply connect the conductors of two cables in parallel on the EM- model terminal block. Two other single-pair senders may be chained with the DS-TPS1A, 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 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 power pair and all three audio pairs are fed through both rear-panel RJ45 jacks. The DS-TPS1A may be powered directly from a 24 Vdc power supply using the rear-panel detachable terminal block. Local power connected to the module is also fed to all connected remote modules. The DS-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. RDL FORMAT-A features superior audio performance that rivals or exceeds shielded wiring. Design simplicity, ease of installation, unsurpassed flexibility, automatic fused power, exceptional hum rejection, low noise, and low distortion provide designers and installers the optimum choice in economical twisted pair products.