Forgot to share this in previous post: I have reworked the schematic with correct part naming (much easier to work with)  

Hi Just wanted to share my build of a lovely cube.  I'm trying to get as close as possible to the linear SE original version. I have ordered this board from ebay seller minishow0328 for as little as 38 dollars (free shipping) http://stores.ebay.com/minishow0328/ I received a beautiful...

Forgot the most important of my findings! Isolation is simply spot-on, perfect!!! It brings just enough isolation but you don't miss a word of conversation when playback has stopped. And that open, free sound. Just amazing. I hardly see the point in using closed headphones anymore ;)

Got the 880. Loving it already. Comfort is really nice, no problem keeping it on for 4+ hours. Cable can be a bit sluggish and gets in my way sometimes, I would have preferred a non-coiled cable. Might mod that later. Love the soundspace on them, love the transient response. Allround...

All right! Thank you very much for your this great reply. I'm particularly interested in DT880 or K702.   Behringer says this about HA4700: Highest sonic quality with virtually all types of headphones >8 Ohms even at maximum volume What should the output impedance be for 250 ohm headphones...

At the studio that would be mostly behringher ha4700 units or avid HD omni headphone output. At home I would like to buy an affordable headphone amp if its high ohm. But I won't be using it at home much, just to check a mix sometimes.

Anyone?

Can anyone recommend a good pair of semi-open headphones for studio use Or closed one that don't isolate from ambient contact with others in studio. For vocal recording use.