Leave things alone long enough and curiosity starts to get the best of you…
Anyone have a Khadas Tone 1, Allo Boss, Hifiberry Dac2 HD, or other comparable unit with RCA output that needs a new home?
The HifiBerry Dac+ Pro I’ve been using for the last 5 years works well but I’ve never heard anything else.
Time for an upgrade when you get bored 
My Pi also going strong still, don’t think about other brand name streamers/DACs since it works well with volumio.
I was reading about hats when building my RPi4, decided USB is the easiest and best output to my DAC :). I understand the older RPi’s had some USB noise issues.
All those HATS are expensive and hard to get where I live, more than the Pi I think.
I’ve been considering a USB DAC since there are so many more options, and once I started looking, I saw various comments about lesser performance via USB on the rPi 3 (mine is a 3b+), as you mentioned.
I also found this analysis that comes to the opposite conclusion:
I suspect my system as a whole is not so finely tuned that I would notice a difference but you never know.
Yeah that’s fair mate, it’s fun to see what you prefer but there isn’t much in it a lot of the time i’ve noticed.
I will check out the link, but for me USB is a simple and cheap solution (and digital is digital ha).
Even those Wiim Pro+ are handy these days, not sure how it would go with Volumio, probably supported I guess. Pi’s are fun projects though.