Ultimately, I am now going in the direction of choosing a new set of headphones. Given the strong performance level of the existing headphone socket in the Rega Aethos. A sensible option would be to build upon it. My overall preference is for open back type headphones providing the trademark open and wide soundstage in my current Sony MDR-F1. Now, as good as these headphones have been over the years, some areas of concern can not be overlooked. Becoming more apparent when comparing sound on my reference system with headphones and without. This is where the gulf in quality and of course price is crystal clear. The headphones just lack the warmth, resolution , depth in soundstage, timbre and separation of the reference system.
All things considered above, what might be some options to explore in a new set of headphones with a budget of $400 - $1000 ?.....Are there any standout performers / perennial favorites among seasoned headphones enthusiasts coming with strong recommendation.