Need help

Listening room.  Have very decent system(s), but none have a headphone port.  

Pro-Ject Head Box DS2 600$
Balanced output , Bypass ....
This is what I have without their  linear power supplie

https://darko.audio/2020/10/moving-upfield-pro-ject-head-box-ds2-b/

Just like with a 2-channel audio system, it’s best if you choose your headphones first to see what kind of amp and how much power you’ll need to drive them properly.  Just my $0.02. 

Lots of choices out there. For $500, I recommend used. Headphone users are as fickle as other audiophiles, and you should be able to find a $1,000 set for around $500. Without a headphone jack, you'll need a dedicated headphone amp, or at least a junction box (like Stax SRD-7) to drive them. Check Audiogon, eBay and Craigslist.

I got Grado GS1000e and Lehmann Linear to drive them. Arriving here soon, I hope. I got them from a dealer vs direct from Grado Labs. A matter of principle for me.