Headphone / DAC advice

[wozzizname]

I'm currently using Sennheiser HD660S headphones via an Audioquest Cobalt from an iPhone 15 using Qobuz as a source. I'm starting to feel an upgrade itch, and wondered where would be the best way to go from here - better headphones or an improved DAC, maybe something from Chord. Any advice ?
I can also listen via a Cambridge CXN V2 / Technics SU-G700M2 amp's headphone outlet so thinking maybe better headphones may be the way to go.

 

[wozzizname]

Use this thread here https://forums.overclockers.co.uk/threads/what-headphones-do-you-own-thread-i-own-dt150s.18215563/ .

You will get more replies and ideas from people that have done the same.

Thanks, I'll head off to that thread.