Here's the list of TOS optical outputs I have so far. Xbox 360, ASUS z690 Apex Maximus, TCL Roku Television 2 Sony CD carosels, Android TV with HDMI and Optical output.I like your update - I just purchased a T9 Pro and had it about a week. It has some serious eye candy, and I thought well the sound is probably sacrificed but the look is killer. Initial listening using the built in ESS dac via usb from my laptop was not impressive although the unit seemed really solid build and they added a few side-vents which I thought was smart and good foresight.
I also have an M300 SE (another new arrival) and when I used the M300 SE to decode the T9 Pro completely changed. I want to say it sounds 7X better, but that is just my subjective opinion. Soundstage, imaging, bass extension, volume was all greatly improved - I just kept repeating wow over and over. I went from probably going to send it back, to most definite keeper. Having a remote for tone controls is just french pastry on top. The aux out works really well too. Liking this M300se/T9 Pro combination, the ESS9018 built-in is a nice feature (I guess), but its quite weak when compared to a better dac. I would like it with no-built in DAC but instead Qualcomm 5125 BT chip which does LDAC & AptX HD codec. My first Aiyama product, I like it a lot.
So far, the only time I have ran into an issue with the Aiyima T9pro handling the Optical input is on the Sony Carosels. If they removed the internal DAC they would lose Coax and Bluetooth options.
While I agree there are usually much better dedicated DACS out there I would want some good improvements to the T9 pro in exchange for the sacrifice of a built-in DAC.
I'd say that combo of the Android TV, no audio Computer monitor, and T9 pro made a great little station.
Now I wish I could find a portable CD player that offers TOS as well.
Maybe there is always a "better DAC out there" but I suspect you hit diminishing returns pretty quick.
I worry about CD's going away. I am having a hard time noticing huge quality differences between the CD's and Vinyl.
This might mean I gotta go buy expensive cartridges ??
I still don't understand the hate for EQs. I have few of them and it is hard to beat dialing in things the way I want to listen to them.
If the sound engineer can do it in the studio, then why can't I as well
If nothing else, an EQ can be of great assistance of getting rough ideas about how speakers tonality is different when compared.
I guess I am probably a perpetual tinkerer and won't stop until I grow bored of it.