I would ask a different question, what is the experience you’re looking to have. Are you looking for a stationary listening experience, or do you want to be mobile? What type of listening do you want to do lean forward analytical list or a more laid back Maxwell style experience?
If it is a more stationary and lean forward, do you have the right AMP? A solid-state is an excellent choice; Examples are SPL Phonitor X or Xe or Headamp GS-X Mini. I am sure the community has a few more names for a recommendation?
For more a laid back experaince, kicked back in your favorite chair with a long cord on the headphone, do you have Tube Amp. I am sure the Crew can come up with many ideas, I am currently using ZMF Pendant to drive the Susvara. There are many great Tube amps. AMP&SOUND like Pendant sister the Leeloo ( little lower noise due to Solid-state rectifier), Eddie Current, etc. Still seeking the perfect chair for my combo so i can have the Pendant next to me with streamer and shut lights off and kick back with Susvara.
Once this is in place you set to enjoy Susvara or Abyss AB-1266 Phi TC.
Now, if you go RAAL-Requisite SR1a, I would just pick up there new RAAL solid state AMP Torq is testing.
Now if you are looking for something more mobile, pair with DAP, iPad, iPhone, Andriod Phone, For dynamics it would be Focal Stelia & Utopia. For Planners right now, I like the RAD-0. Note this Headphone can also be used in the context of above, but you do not need crazy power for them, For the Focal’s, you will not need anything more then RME ADI-2 DAC fs to power them.
On the RAD-0 @Resolve personally, it holds its own with LCD-4 now that I have A/B them on several sources. I love you do not have to eq it. The best part is you save 120 -170 grams off your head with the current crop. You can drive it with significantly more sources and still get an enjoyable experience.