The Russound MCA-66 Digital multi-zone controller amplifier provides up to six zones of distributed audio. Scalable to 36 zones, the MCA-66 provides numerous options to tailor every room in residential or light commercial distributed audio systems. A variety of input options have been engineered into the MCA-66 to connect up to 6 sources. AV source input options include 6 Analog, 3 Digital (up to 3 coax, or 2 coax and 1 optical), 1 paging, and 1 Bluetooth extender connection. The Bluetooth connection allows the installation of the MCA-88" an equipment rack, while remotely locating the optional Russound BTC-1X Bluetooth receiver up to 300' away. Additionally, the BTC-1X improves audio quality through the high-performance APTx audio codec. An RNET link allows for metadata transmission, linking multiple MCA controllers and connection to all Russound RNET Smart Sources like the ST1 AM/FM external tuner. All MCA products are Ethernet-enabled devices, allowing for IP-based features and control. RIO (Russound I/O) allows Russound IP-based control systems to integrate with, control, and communicate bi-directionally through an open protocol. In addition to dedicated keypads and touchscreen control options, the free My Russound App (iOS and Android) controls all Russound Ethernet-connected products on the LAN, including the MCA-66 and its source components.