No problem mate, I wasn't criticizing you for not providing more details, I was just saying that giving more details would help in order to focus on those products that might best fulfill your needs but I understand. ;-) Speaking about the metal music genre, my suggestions goes for Shure SRH840 as for closed back headphones. You can get them for about 150$/€ and they sound great, plus they have very good isolation, in case you ever wanted to use them in noisy environments. Their direct competitor is Beyerdynamic DT770 Pro (mind that I'm referring to the 250 Ohm version). Pretty much same price and same sound quality. They differ in sound signature though: the Shure's are neutral headphones, very well balanced. Bass is thight, mids are very present and highs are crystal clear. The Beyers stand on the other side: they're more dark, bass is punchier and highs are a bit subdued. Overall they're both great headphones, it's just a matter of deciding which type of sound suits best your taste. I personally went with Shure's because I like clear, airy sounds but if you take into accounts other uses like movie watching and gaming, you might appreciate a little more bass response.
If you want to go open back, you can go up with prices (and quality as well of course). Generally speaking, open back headphones are better than closed back, because, simply put, air can circulate better and sounds are not restricted. This said, always considering metal music, in my opinion the best options are Philips Fidelio X2 (299$/€ but you can get them for less, even 199$ in the U.S. if you're lucky), AKG K712 Pro (you can get the special edition here on Massdrop for 199$) and the Sennheiser HD600 (which are the pricier ones, around 300+$). Philips are a little bit like Beyers, with a sound signature going toward dark sounds, whereas AKG and Senns are more balanced. Mind that while the Fidelios (as well as the Shures) can be easily driven by portable devices like smartphones and iPods, Beyers, AKG and especially the Senns require a good amplifier to express themselves at their best. You can still plug them into your smartphone if you want, but you're probably not going to be satisfied. My final suggestion therefore goes to Shure SRH840 if you want closed back headphones and Philips Fidelio X2 if you want open back headphones, with the bonus of going up to Sennheiser HD600 if you want to spend some more. Anyway, the Fidelios are already great headphones and from what I've heard they pair really well with O2+ODAC.
Hope this helps! ;-)
One issue that I came across was with mumble. It seems to affect other DACs and mumble. It is a simple fix, mumble does not like the HID-compliant consumer control device that is installed when you plug your O2, disabling will fix any issue with mumble hanging and not recognizing your PTT key for 15 secs when ever you plug or unplug a USB device.
I was looking for a loud amp. This one delivers, I don't even want to pus the gain button. The power delivered is so intense that i can feel the kick drums vibrating my headphones... amazing.
Can someone recommend me another pair of headphones? I listen to a lot of metal, jazz and Classic/Romantic era music and I do a lot og gaming (MMOs, Mobas and FPS). From time to time I will listen to top100. I would really like to break a pair of cans to the new DT album The Astonishing that is coming out.