mhvuThe phone can definetely power the headphones, but the dac isn't that great. Using a cheap portable amp/dac combo would benefit the headphones greatly, but the sound quality is still gonna be pretty good.
CokemanThanks Cokeman... any suggestion on an amp compatible with S8 or Android phone in general? I'm looking for portalbe solution where I can use that amp for both desktop setup and smartphone. Company block access to install anything in PC so I might have to use my smartphone to hear the sweet sound coming from the HD6XX
mhvuDepends on what you want to spend. There are hundreds of separate amps and dacs and amp/dac combos, from @ $100 to many $thousands. I went ahead and got in on the TEAC AI-101DA desktop amp/dac., mainly because it has a separate sub-out, so it'll work for passive speakers with a sub, powered speakers/sub, headphone amp, DAC, and Bluetooth capabilities. Not bad for $200.
mhvuYou can also look up the "Schiit Stack" for very inexpensive but very well-regarded sound quality and lots of capabilities, including utilizing the amp as a pre-amp for a system.
mhvuNo I would not recommend that. It simply doesn’t have enough power for 300ohm cans. But don’t worry about smartphon use, you don’t want to use the 6XXs portable. Since they are open people around you will hear exactly what you are listening to. For the same price I would go with a Fulla 2. But I always recommend a Schitt Stack as your best option.