I have an old hardware/software compatible solution that allows me to record multi-channel ATSC AC3 (AC-3) audio without digital rights management through spdif input. The software is called HDPVRCapture, and it’s a Mac app that can be used with my Hauppauge HD PVR 2. It works great with audio, but its developers have dropped support for it. I have already found a better solution for video capture (Blackmagic Recorder 3G), but so far I can’t find anything that works for audio. A Creative Labs Sound Blaster X4 can bounce the optical input to two channels, but absolutely cannot pass all 6 channels through, at least not on a Mac. My Mac is M1 Silicon MacBook Pro 16", so I need an interface to accommodate the S/PDIF optical input. I can make HDPVRCapture.app work, but it’s through a hacked solution involving preserving the settings file that was cached and saved when the software was still actively supported. There’s no way the hack will survive many more Mac updates. Thanks.