(Sorry if this has been answered already)
Have a look at the
MiniDSP DDRC-88D.
The thing that kills me in this product design is the straddling between pro-audio and consumer audio that all these vendors are doing. One can blame the content industry for going via the DRC enabled HDMI route but why isn't the rest of the industry not directly catering to the copyrighted DRM industry making it easier for other use case instead of trying to straddle the middle between pro-audio and consumer?
Would it have killed the miniDSP guys to have provided a USB-in/USB-out DDRC-88D? Sure you can use a UDIO-8 but that is another $300 and another power supply to plug in. For what benefit?
Would it have killed Okto to provide a 8 channel DAC with the option of a TOSLINK instead of AES/EBU? So you can connect your stereo streamers or players? And even switch between them?
Earlier I tried looking at a Motu as multi-channel DAC. It has balanced TRS out for 8 channels. But if you want to stick it into an unbalanced RCA inputs of an amp, you need to find a TRS to RCA jack in which the ring is disconnected (while every such cable available has the R and S shorted) or use a TRS to dual RCA and leave one RCA hanging disconnected.
All these seem like self-inflicted wounds in the industry and they wonder why the all-in-one convenient AVRs are purchased by most people than deal with this crap. This has nothing to do with DRMs and the evil content industry or the greed of the mass-market brands.
Not saying hobbyists cannot do any of the above work-arounds but that is not a very large market requiring these vendors to straddle the pro and consumer audio which decreases the market for the latter in the first place. A very cyclic situation.