Got mine. Slight if any improvement over Beyerdynamics 770 and HD598. Works great from my axon cell phone, with or without amp (massdrops O2), digital downloads (mp3 etc) sounds the best, FM and spotify are good enough. Obviously without amp I need max out volume. I tried few random classical CDs with my old boombox and Toshiba HDA1 - it's ok, yet I expected more.
iatsbohdanI had that feeling that adding yet another Sennheiser to the collection is waste of money, yet getting $400 "audiophile" cans for half price seemed like a great bargain. Should say I really liked the packaging, cans came in big nice box - I can put my most expensive cans into storage and take out on rare occasions to impress guests or if I am in mood to listen to all the minute details of a recording. I also ordered a SDAC, they say good DAC might greatly improve quality for HD650/6xx. Also technically it is not just mp3, flac, ogg etc are good too, just cann't remember all these formats - player typically hides the file type. Do you think Tidal will be a lot better than Spotify?
freemusicThis is being driven off a cellphone jack or an O2?
So my Ferrari arrived. Slight if any improvement driving over dirt roads around the farm or black ice in the middle of winter.
RockyMountainsThe axon 7 actually had a pretty strong amp in it and the dac was better than average the last time I heard one. But he's obviously not joking about using the axon 7 as his reference point.
freemusicI guess you're not joking then?
These headphones are not designed to be run off whatever it is you're using- they are very high impedance-about ten times more than most portable headphones. And regardless of what DAC is in the phone, it's still just a phone. This is why you probably won't hear much difference beyond volume.
RockyMountainsCell phones with better audio chips (Axons, LG V10/V20/V30 , HTC 10) can drive HD650, even though depending on taste and hearing an amp or dac would probably be an improvements for a true audiophile. Note the drawback of strong dac/amp in the phone - it draws too much power, but it should be possible to switch to a standard one. I a bit dissapointed with 02 yet it is actually good that phone copes without O2 - I might fancy to use them in Gym or while commuting. In fact what I appreciate in Massdrop's 6xx is cell phone ready jack. it is more convenient than my HD598 as it does not need adapter for cell jack. Note the drawback of strong dac/amp in the phone - it draws too much power, but it should be possible to switch to a standard one. Nevertheless I ordered a SDAC and will give it a try. I might have a cheapo usb hdtv/audio-video capturing device yet it is not compatible with th Win10 , I did not try my old Sansa clip and Sony mp3 players - based on other headphones, they do not measure up a good cell phone neither in SQ nor amplitude/volume. BTW here is a bit dated review of few phones https://smartphones.gadgethacks.com/how-to/top-4-phones-for-music-lovers-audiophiles-0175956/
minimiThere's a lot more to it than just the chip selected. A phone is highly miniaturised, with all components packed in there with space and fit being the primary criteria for design. And the power supply remains a low capacity 7.2V or 3.6V battery versus the 20V+ wall adaptors that even midrange amps use.