Hey alanmcgregor ! I hope you're doing well 
So I have my Xbox Series X arriving in a few days but I think I find myself in a bit of a pickle regarding audio!
My current setup on PS4 is: Topping D30 DAC, JDS Labs Atom Amp, Blue Yeti Mic and DT990 Pro. This is all connected using optical for the DAC and Amp and USB for the mic.
Now with XSX, there is no optical option but I've also come to the conclusion that Xbox are not even that flexible with third party audio options either. Eg. My mic likely won't work plugged in via USB(?)
So with my equipment in mind, what solutions do you think I have? My monitor does not have an optical connection. I have heard about hdmi optical splitters, but I'd hate to use this if it means it will compromise things such as the ability to achieve 120fps.
If the hdmi optical splitter/audio extractor meant that it would cause side problems such as inability to reach top frames per second, or some lag - I would much rather avoid it completely and just buy new equipment that would work with XSX
FYI my monitor is AOC 24g2u 1080p 144hz hdmi 1.4 with freesync capabilities and as far I understand the hdmi 1.4 /freesync capabilities means I can play games at up to 120fps with 1080p.
It almost seems as if I might be forced to buy an Xbox licenced mixamp such as Astro mixamp and a new headset such as Sennheiser GSP 500 in order to have top audio with the new console.
I'd really appreciate your thoughts.
Best regards
JamesFPS
Hey
JamesFPS welcome!

Lucky guy I can't get my hands on a XBSX I will wait for next year I guess.
You have a really nice audio setup, congrats!. Exactly just like misdah put it, you need a proper splitter or extractor.
SPDIF Audio Extractors doesn't add input lag at all, they are only cables routed in to a different format, takes out the digital audio signal from the HDMI and put it on SPDIF (USB is another way to pass digital audio). Digital video signal is passed through, you only concern on this should be how? which format outputs.
Ideally for a device that outputs HDMI 2.1 having a HDMI 2.1 Audio Extractor should be the best match. Currently there are only HDMI 2.0 which does 1080p / 144Hz and 4K / 60Hz.
HDMI 2.1 does 4K /120Hz,
I doubt current gen can do that on AAA games, and that's why mainstream audio extractors are settled to 2.0b, some important devs are acknowledging 4k/60Hz steady it will be the goal for "performance mode" on most games, you wonder why XBSX and PS5 went for HDMI 2.1 then? for 8K playback.
For 1080p at 120Hz you need a monitor with a HDMI 2.0a or HDMI 2.0b input. Unfortunately yoursr is HDMI 1.4 it can do 1080p at 120Hz only via Display Port. If you want to keep the monitor, get either an
active cable Display Port 1.2 to HDMI 2.0 or and an adapter, both are transparent.
Now for your Blue Yeti Mic.
Microsoft Xbox has a closed audio ecosystem compare to Playstation where is compatible with a wide variety of USB Audio Codec, that's why Blue Yeti works directly with PS4/PS5 via USB same as almost any USB sound card.
In order to make your incompatible Blue Yeti USB Mic work on Xbox Series X, you will need a device that works with Xbox Series X and gives you:
Mic Input then feed this input with your Yeti Blue output signal(your voice) coming from mic's headphone jack, mic requires to be connected USB for power.
That's how was done on XB1X, put the headset adapter, use a
Mic/Headphone Y splitter connect the mic input from the adapter to the Blue Yeti Mic Headset output using a 3.5 male-to-male extension, connect the Yeti's USB to the console for power, control levels at the console audio menu.
Not entirely sure if the Official Stereo Headset Adapter(the one goes under the controller) is compatible for XBSX (it should be according Microsoft). MixAmps does.
Official Headset Adapter for Xbox Consoles
Keep in mind: if you are using your Blue Yeti Mic for streaming broadcasting your voice to your viewers only, then you don't need to be working on the Xbox Console, connect the blue mic USB to your streaming computer. However if youe you are using the mic to talk with your team on Xbox then, you need the adapter.Hope it helps!
DanielClemYeah I agree with
thelastword get the amp get the HD660S and enjoy. I can't make the same recommendation to
JamesFPS or any other fella who has tried/delighted decent audiophile DAC. But being completely honest, I have to say in order to get the best audio experience on a better headphones, you need an equally good DAC/Amp and MixAmp isn't,
far from it.