The HDSPe AoX PCIe x4 audio interface cards combine dual network ports with headphone output, AES3, MIDI, and internal expansion headers for up to four MADI ports. Whether used in a Thunderbolt™ expansion chassis or built into DAWs or audio processors, these cards send and receive up to 512 channels of audio and provide numerous mixing and routing capabilities. Occupying only a single slot, the PCIe x4 interface transmits and receives up to 512 channels of network audio signals on two separate RJ45 connectors. The network audio channels can partially be replaced (or extended in case of the Milan® version) with MADI signals by adding up to two optional dual optical or dual coaxial extension cards. It is therefore possible to integrate four MADI input signals, four MADI output signals plus up to 256 network audio channels per direction within a single audio interface for the first time – on macOS and Windows.