I bought v5i-d dual op-amps, and kept testing them on EVGA NU Audio, Asus Strix Soar, was plenty happy, after a while i received an offer by Burson to try out another set of op-amps in exchange for a review. Didn't manage to make v6v work in NU Audio card, but they worked wonderfully in Asus Strix Soar.

On the first day was still sceptical if i heard any improvement, so i carried on to several days of listening in games and music (mp3 files). I am not really sure how to compare v5i-d to v6v, one thing is that i like both of op-amps.

Headcans used: sennheiser Sennheiser hd560s, Philips x2hr, AKG k702, arctis nova pro wireless in wired mode.



In Songs

Noisia & Teebee - Moon Palace: bassline sounds extended, full, warm, percussive sounds detailed, no muffle, no distortion even at all windows 10 volume levels, very wide stage

The Halo Effect - Shadowminds: lots of energy in guitars, drums are weighty, very musical sound

Omnia - Dance Until We Die: lots of micro details, vocals don't get drowned, drums sound potent once again, more full, string/piano instruments don't get muffled, separation between instruments easily recognizeable

“The Prodigy" on an Acoustic Guitar by Luca Stricagnoli - Fingerstyle Guitar: low end thick and extended, strings full of energy

Mammal Hands - Transfixed: details, separation and wide stage on full display

Wheel - Dissipating - lots of details, warm bass, no fatigue listening, easy to separate instruments between each other once sound gets too busy

Best pairings for me were Strix Soar with v6v + hd560s & k702

In Games

There is a very good awareness of footsteps, bullets, thrown grenades directions, mainly tested CSGO and Crysis Remastered. I enjoyed FPS gaming the most with hd560s = k702 headphones, then X2hr and Nova Pro Wireless in that order. Can't say soundstage improved massively over v5i-d, but positional cues were very clear clear.

Conclusion

Wish I was able to make V6V work in EVGA Nu Audio too, as v5i-d worked greatly on EVGA and Asus card. After several days of using single V6V on Asus Strix Soar I started to enjoy using it in all applications more and more, at this point not sure if i should put v5i-d back on Soar or keep v6v inserted. Asus strix lineup is unique, because you can use Op-amp extenders and easily put Asus shield cover back on top and hide Op-amps neatly. Overall it doesn't feel as if this or other op-amp is better, it's as if you like how it sounds when using. Still recommend V6V, cannot find many cons, give them some time to listen to evaluate better.

Wow, i am soundwhoring in fps games now, i feel more aware of suroundings, and enemies steps distance, you can easily say the difference between some slightly cheaper and very cheap headphones!!! Had senn's HD429 + 558 + 598 open backs, and akg 550 closed backs before, oh man, sony are better in soundstage among them all, not sure by what margin, i'm not audiophile, but since i've started checking more expensive headphones like sens 5xx series, akg, i can tell the difference.

They are very light and comfortable, the other most comfortable headhpones i ever had (using right now) motorizer headphones. I love thin cable, makes me want to take them out with my smartphone sometimes, cable is very handy. They look fragile in photos and once you open the box, and when you take them in hand, you easily feel - they are sturdy, firm, flexible headband of metal, cloth material and rubber tubes inside shouts - quality. Seriously, when you put them on your head and turn the player on, you don't even care if they look fragile. Thin, firm, metal headband is another reason to fall in love with them.

I'm not good talking about lows mids and highs at all. All i can say these cans are lovely with music for me, just because they don't have overpowering bass, it's there, it's tight, not tiring, i love it. Instrumental music, modern jazz, classical, psychedelic/stoner rock (hidden orchestra, kingston wall, animals as leaders), they'll do fine with these genres. Female voice sounds great with these. Wish they were somewhat better with crushing heavy more agressive metal other than instrumental progressive metal. I am not very good at reviewing headphones.

Excelllent headphones, coming after ss 9h headset, senn's 429 558 598 and i love these most, i differentiate details better in vocals now, i can say if vocalist is blowing into microphone while singing, there are more details in vocals which i cannot explain in english,  coz i'm not good at this section in english. Bass is not overwhelming, it is what i like most, not muffled, also if you EQ the bass it will sound much better as it did on my nokia with eq presets. Priority is for home use, but it's perfect using outside with phone, cable thickness is not the problem, as you can roll it around the phone, and put everything in the pocket without all stuff sticking out too ugly.
 
So much better in games with hearing steps detailed, soundstage is right as i wanted, with 9H i wanted to hear games world better/wider than i heard, akg550 fills this hunger, love it. Orientation in fps games maps is very good right now for me.