Hi! Is anyone still using the Nuforce uDAC 2? I updated to OSX 10.11 and my audio no longer works. I did read a few other people with this, just wondering if any smart people here found a workaround :-)
Just pulled out my pair of 668B's from the garage. I packed them away after trying them for a bit last year because I remember them being very uncomfortable. Had a random urge to listen to them again, so spent 5 minutes and did a sock mod....and am loving them! I'm glad I didn't sell them - for the $40 that I spent on these they are absolutely great.
I would second the Denon. The AKG is a great pair (I sold a k702, realized I missed them, and bought the Q701), but what I thin you're missing is "warmth," particularly when you compare them to speakers. The previous generation Denon headphones (Dxxxx series) still gives you clarity, but adds a bit of warmth to the sound to make it more lush, but not veiled.
You'll get the best noise isolation by using earbuds such as the Shure SE215, but if you need to go with full sized headphones I'd suggest the Phillips Downtown. They have a remote, and e cushion is made of memory phone so it's comfy and conforms to your earshape. At $100 I'm not sure if there are any active noise-canceling headphones worth it.
While the V6 has a decent amount of bass, I think the defining characteristic of the V6 is the large amount of treble you get. Having a pair of "darker" headphones would help, IMO. Try a pair of Sennheiser HD558, HD598, or even the Audio-Technica M50 (the M50's would be more along the lines of the V6, maybe not the type of upgrade you're looking for).
Hope that helps!
I think this is too late, because you've already gotten the K240, but the AD700 fits your bill nicely in terms of pricing, and sound aspects. They are great for classical music. Available for $100 new, or $85 used on Amazon.