That sound very interesting pindac.
How about attenuation if a source is too hot like my phono stage output?
Do you consider preamp input gain control?
Now a wise old recording engineer of 30 years experience I was taught the best way of capturing the cleanest audio in both analog and digital is getting your input gains spot on. Both lowering noise floor and avoiding any possible clipping & distortion.
However.... only recently have I managed to put this into practice in my home HiFi system. No one wants a mixing desk in their lounge least of all my other half.
After recently experimenting with a few bits of semi obsolete pro audio gear I had shelved, I now run my turntable phono stage, my streamer, and the TV box into an HHB CDR 830 machine which provides 3 main functions:
1. It provides CD transport with fixed output gain.
2. it does DAC duties for my streamer and EE TV box, and sounds superb.
3. Utilising it's dual digital (coaxial and optical) and analog input gain controls it evens out the output gain of all 3 sources ; phono stage output was too hot for amp , the streamer and tv box too cold and varied wildly... things were all over the shop... But this now provides one perfectly matched output gain for my integrated amp's input circuits. I simply switch what I'm monitoring on the CDR and don't have to switch amp inputs. The amp in use is a 1963 Japanese tube amp so it does need to be fed with the ideal amount of millivolts to get the best out of it's pre amp stage and 20w per channel output handling. Probably more than a modern integrated amp might.
If you find yourself adjusting volumes between your sources then I can recommend doing something similar. It's a bit of a revolution in my front room!