According to Asrro - because there is a lack of optical port on PS5, you need to buy an an optical port adapter to be able to use your Astro Mix Amp on PS5.
The alternative for wired headsets is ok - yiu can plug them into the controller, BUT Ive just dine that and it sounds trash without the MixAmp processing the signal. The surrounding sound is much reduced (at least on BF1) and it somehow manages top sound too bassy AND tinny at the same time
Needless to say the adapter (whish is required for the wireless sets) is sold out 'until after the new year' so its going to be a bit crappy for Astro owners.
I'd be spitting blood if I was on the exec team at Astro - how can they now be aware sooner that this is going to be required so they can made enough adapters?
Presumably Sony did this on purpose to shift more units of their own own headsets.......
On tiger bright side, I can now confirm that the PS5 runs PS4 titles beautifully. The frame rate and extra fidelity that the PS5 brings is really something. The game looks and feels amazing. Much more like a PC experience.