New headphones for a Denon x3400H receiver

hello- brand new rookie here on this website. I have a Denon x3400H receiver and am looking for a good set of headphones ( movies, music = easy rock, instrumental , jazz). Have been unable to get confirmation on what the volts/amps/ Ohm's, etc. that the Denon is sending out of the head phone jack. Not interested in gettign a separate headphone amp. I prefer open back, open stage accurate headphones. Do not like boomy bass, or super tinny treble/cymbols. So pretty flat, not bright. Comfort is important = have tried Beyerdynamics 990 premium and pro's and they were good. But not sure about using them on my Denon. Maybe the 990 premium 600 ohm , or Seenheiser 600, or the massdrop 6XX. Options, opinions, and just info much appreciated.
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Aug 12, 2019
OK - I have been using the 58x for several days now and yes- they are nice - very dynamic with out BOoM BoOM bass. And yes, they get very loud without much distortion when the AVR is turned up only about 50% = easy to drive. So, now if I decide I want something much higher end I know the AVR can work well with a headphones with those same type of specs ( 150 Ohm, etc. ) . I have not had a chance to really listen to music yet - but movies/TV sound great. Not used to wearing any headphones so they did get irritating on my head after 2-3 hours - but my ears did not get hot - which is usually my #1 complaint. I have a rather large head - so I am sure they will stretch out a bit and become more comfortable.
Owned two Denon and one Marantz receiver in the last 15 years. It's honestly not an optimal choice for headphone listening. I started out with an HD650 and a Denon AVR1905 many years ago, an amp does make a difference. If your x3400 can downmix and output digital signals via the zone 2 output that is how I currently hook up my HP amps to my receiver (Marantz SR6012). If you liked the DT990 then you aren't completely averse to bright headphones. The 6xx and 4xx are both good entries sub $200. The 4xx would probably be the best option for use on a receiver as planars don't have the same issues with a high OI.
Aug 6, 2019
Awesome, thank you for spending the time to teach me. Just read and saw reviews on the monolith 1060. They are on sale over at Monoprice for $250 . LOL. Now I am even more torn and confused.
Any time... spent many many years accumulating knowledge and slowly working myself deeper in to this hobby. Happy to help out where I can, those 1060's are also a planar headphone so should work better from a receiver than most. I don't personally have any of the monoprice headphones but I've been buying their cables and adapters for longer than I can remember.