4K headphone + headphone amp/dac system recommendations please

If you’re sensitive to fatiguing highs / fatigue in general, Grados are about the worst choice out there. I listen loud and most Grados are just outright painful after ~30 minutes. They can be a lot of fun at first, but the fun wears off fast. Pad swaps, yada yada. Been down that road a few times. 

The (somewhat) exception to this is the ancient HP1000 series "Joe Grado" headphones (with flat pads). Those are GREAT and look beautiful too - but made in the 1990s and ageing more every day. 

Since you want musicality with lush mids, the classic combo of Sennheiser HD580 / HD600 / HD650 coupled to an OTL tube amp is hard to beat. I loved that sound and had to jump to electrostatics to find my "next level". I hate their newer HD800 and derivatives. Such unnatural sound. 

I’ve had mixed experiences with planars Meze / HifiMan / DCA - they can be good, but nothing that has stuck to me for long. 

Electrostatic headphones can be truly magical; the detail and clarity is the best in the headphone world AND the fatigue factor is lowest because it also has the lowest distortion. But driving them properly is hard, and they can ONLY be powered by specialized devices. I’d recommend Stax Lambda L700 or ES Lab ES2a / ES1a with the best electrostatic amp you can get (e.g. KGSS, KGSShv, KGST). The new Stax SR-009D and 007S also get good ratings, but 007 is very hard to drive. L700 is easiest to drive, then 009D, then ES1 / 2, then 007. Probably, L700 is the best choice to start out.

@mulveling 

Thanks for your suggestions. Ideally, Id prefer to stick with SS. Can you think of any headphone/SS amp pairings that would yield "musicality with lush mids" or is that asking the impossible? 

please go to CANJAM. I am an introvert to and go to CANJAM almost as a religious event lol. @stuartk 

reason why to go to CANJAM is in these two videos:

1 - https://youtu.be/W9gWIu3EP84?si=aaoC5SFmfj5cnG0x

2 - https://youtu.be/JVW53wmo-04?si=JcFGCXqWBayZKy-G

3 - https://youtu.be/s0nZCXyDTz4?si=6CnxWUgM9y07Qi_Q

Thanks for your suggestions. Ideally, Id prefer to stick with SS. Can you think of any headphone/SS amp pairings that would yield "musicality with lush mids" or is that asking the impossible? 

That's a bit tougher. SS can never be as lush as tubes without becoming a dark mess overall. There are definitely SS amps that "lean" warm, and that can be a pretty nice mix with the Sennheisers I mentioned too. Certainly avoid the Gilmore Dynalo / GS designs - those are GREAT amps but they do not lean warm at all. I'm not sure what modern SS dynamic amps are good for that, these days (I moved on to e-stats). Some of the older Headroom Max amplifiers were pretty nice and leaned warm and particularly sounded amazing with the Sennheisers in balanced drive mode (for the models that had it). 

Attending a local head-fi meet or Canjam is an excellent suggestion. Like with all things audio the choice of cans and amp is very personal. Just a warning the e-stat headphones struggle more in an environment like that because they're SO open to the ambient noise, and their amps don't have reserves to just crank the volume with endless headroom like on most dynamics. 

My fav is the RAAL SR1a, but I won’t recommend that since it is a detail king. A very engaging and musical phone is the ZMF Caldera Closed. I was very surprised I liked it. I was at a mini-CanJam meet and a couple of folks there who had cost no object phone systems gave me to listen to the Caldera.

Caldera Closed LTD Walnut Burl – ZMF Headphones  ($3300)

I have a Schiit AsgardX headphone amp with the MESH DAC. It is surprisingly good (the DAC). The amp was expected to be very good since it is based on the Schiit Mjolnir 3.

Schiit Audio: Audio Products Made in USA  $549

I was planning on getting the Caldera Closed to use with my AsgadrX but decided to save cash and got the Meze 109 Pro used for $500. Since I do not listen to this bedroom system much it was a good choice.

BTW - that CanJam show in NYC had the introduction of the new Allnic ASRA DAC. I heard the $6.5 ASRA headphone amp at the min-CanJam and it was superb. I am trying to get my friend (who sells the ASRA) to convince Allnic to add preamp out from the amp so I can use it as both a preamp and headphone amp.