is it true if i want to connect direct to my iphone x or samsung note 5 i can forget about this headphone as it won't be enough to drive it even if i max the volume on the phone? minimal i need a portable dac/headphone amp?
barefooterbarefooter: That's pretty much true. But also, there are lots of low impedance headphones that you can easily drive them straight from your portable sources (i.e: AKG K550, Philips Fidelio X2) that still can bring in par quality with this Sennheiser HD 6XX. These HD 6XX needs power to drive them properly which can not delivered by sources like phone alone.
barefooterYou want a desktop amplifier like the Gustard H10 or Matrix M-Stage for HD6XX at minimum for it to sound its best. If you want things simpler, there are alternatives like purpleplum said. Headphones that don't need the extra hardware will end up sounding better straight out of portable devices versus using HD6XX in the same manner.
barefooterYou can connect them to an iPhone (with the supplied Apple adapter, if you have a newer iPhone without the earphone jack). I have an iPhone 8, yes it drives them, no it's not going to rock your world--but you'll be okay until you figure out what kind of amp or DAC or combo you want. I opted for an OPPO and the improvement vs no amp is very noticeable (much louder/stronger).
barefooterI’d put my money on a Combo unit, but if not, you’ll get more benefit from an Amp-only unit, than a DAC-only unit. It’s helpful to have something that lets you adjust Gain and Base.
Good luck!
RayFThanks RayF! Now looking at the O2 and Cavalli in massdrop. And also the ifi but not available here, wonder anyone uses them and good to drive this headphone or those AKG ones?