t1 /hd 800 + wa2. new and old versions still good, great synergy that is very hard to find at any price point. there are amps that are more resolving and better overall, but for pure enjoyment and the sweet silky smooth sound the wa2 adds to the music, its tough to beat.
next significant step up is in the 3K+ range, a fully upgraded wa2 gets very close to those and can be preferably in some cases.
only 2 sets i found better in every way where the hd 800 / apex teton combo, as well as HE-6 / WA5 / HPA5000 combo, with upgraded tubes both these combos cost well over $7k for amp and headphone alone, more than triple the price of this set. thinking about it, the teton or hpa5000 is the natural upgrade to wa2, as theyre both otl & ocl designs.