Professional audio engineers can now access up to 512 channels of pristine audio through a single PCIe slot with the HDSPe AoX interface cards. These compact powerhouses feature dual network ports alongside headphone output, AES3, MIDI connectivity, and internal expansion headers that support up to four MADI ports. Built for integration into Thunderbolt expansion chassis, DAWs, or dedicated audio processors, the cards provide extensive mixing and routing capabilities that meet the demands of modern professional audio workflows. The PCIe x4 interface handles transmission and reception of up to 512 network audio channels across two separate RJ45 connectors. Optional dual optical or dual coaxial extension cards can replace some network audio channels with MADI signals, creating unprecedented flexibility. This configuration allows integration of four MADI input signals, four MADI output signals, plus up to 256 network audio channels per direction within a single interface - a first for both macOS and Windows platforms. Despite the massive channel counts available, the ¼” stereo headphone jack maintains prominent placement on the card for critical monitoring purposes. Users can monitor any signal reaching the card from the computer, network, or optional MADI inputs. Additional connectivity includes stereo AES3 digital I/O and MIDI via breakout cable, creating a comprehensive professional interface solution. Channel management occurs through a two-step process using either driver dialogue or web interface. Users first adjust the balance between network and optional MADI channel counts, then pre-select which inputs feed the 256-channel TotalMix engine for optimal workflow customisation.