I cannot listen to solid state anything anymore. Has to be R2R DAC and tube amplification. Maybe I am used to that tone.
I have a few setups for headphones. The main system is Lumin U1 Mini with linear power supply, Denafrips Pontus II R2R DAC (latest firmware) going fully balanced into a Woo Audio WA22 tube amp to balanced cables on Focal Utopia, Meze Elite and a few other nice headphones.
A second system somewhat portable is a Raspberry Pi 4 with linear power supply into a Denafrips Aries 12th Anv R2R DAC single ended into a few different amps depending on the headphones....Icon Audio HP8 mkII (will run pretty much anything - surprised how good it is for under $800 used from TMR) also Feliks Euphoria for ZMF or other high impedance headphones, AmpsandSound Forge (runs about anything and will blow out your eardrums if turned up with kicking bass) and a Dragon Inspire IHA-1 (beautiful sounding but finicky about tubes and headphones - need to tube roll to match the particular headphone).
If you must buy solid state then Naim Uniti Atom HE is nice all in one (selling mine). Great tone but a little weak headphone amp for high impedance. Fine for most mid to low impedance headphones.