Presuming Ed wrote:Thanks for more workaround ideas, but I’m not looking to add more kit to the equation or use a process that the family can’t / won’t follow.
Unless there’s a firmware update to solve this (and it sounds like it might not be possible) I think I’ll go back to my ADI-2 DAC and my passive pre amp. I would have liked the loudness function and a remote control, but it seems like it’s not worth the bother.
Obviously, make the call that you want to make. The following are just my observations in response to your message as someone with similar configuration who has been stymied by the challenge of clocking as well...
I understand not adding more kit as a general principal. But the USB->S/PDIF is just a simple USD $20 dongle that bridges the USB digital signal to an S/PDIF digital signal. And the D10S is a USD $110 option whose main added benefit is that you gain a visual display showing the incoming bit rate / format in case that is of any help. In your context, I'd recommend trying the dongle.
This approach is no different from a family use perspective. They would now select between (Analog | S/PDIF) instead of (Analog | USB); and all of the challenges of locking a sample rate for the ADC stage disappear.
Moving the digital input off of the USB port also opens up the potential future option for using the USB as a multi-channel send/receive should you ever wish to do off-board room correction or other mixing in the future (e.g., using a RPi or other device). And otherwise, it at least frees up the Pro's internal clock so that you can control the sample rate that is used for the analog input and also the digital (i.e., when doing DSP correction).
Reverting back to your existing ADI-2 DAC is by far the cheapest option.
The ADI-2 Pro FS R is an amazing piece of kit; as is the Pro 2/4 SE if you want separate sub outputs. If you were convinced the loudness, the other functionality, and the ADC pre-amp quality was worth it, you would not even be considering reverting back. But conversely, the Pro is a dear price to pay for functionality that you could live without. Or that you could live without for another 2 to 5 years while you wait to see what comes next from RME or other vendors (i.e., new additional feature capabilities, revised firmware, lower price points, etc.) that would be worth the cost of moving beyond your existing ADI-2 DAC + Preamp combo.
For what it is worth... as someone who loves their RME ADI-2 Pro FS R in my context (desk audio at my home office) and would never give it up unless upgrading to something newer and better, my gut instinct is to suggest you revert back to the ADI-2 DAC and Preamp for the time being. And then take another run at this in the future time if anything changes in the vendor space... or if you later decide you can't live without the Pro's loudness and other features. And in the meantime, also keep an eye on other solutions coming along that primarily target home audio in a living room vs. RME's target of professional audio for studio and live performance.