Vacuum tube amplified headphones...

....and, Yes....it’s PRC.
Sorry ’bout that, but...since it appears there’s more of a market (or an interest in finding/making one) for an item such as this that’s not US nor EU....or anyone in existence to ’run it up the flagpole’, flip, flop, or fly...🤷‍♂️

Interesting chip, tho’...*G*

...besides....they're already fully-funded, and 'you can be the 1st on your block'....forum....group...brag bunch....*L*

"It sounds to me like I am listening on vinyl" - LOL! Plenty of falsehoods here! 

@jasonbourne71 ....just the piano player here, no judgements on my part.

"Hands where you can see them, officer...." ;)
There's pro PA gear that's used to 'create that tube sound', both live and studio for quite awhile now.  So, as for 'falsehoods'...I'll pull an Officer Bar Brady:

"Nothing to see here....move along..."  *L*

Their claim that tubes are better for music listening is a spurious claim that won't stand up in court!

Plenty of choices already for those desiring a tube-output headphone amp! Anyway, I am unfamiliar with the cold-vacuum device they plan to use. How does it compare to the standard triode tube?