The only difference is the magnet in the drivers as far as sound is concerned, but more importantly the 7506 has a 'pro' very long coiled cable while the V6 has a shorter, straight cable.
From what I understand, the V600 is not in the same league, but you should check that at Head-Fi.
My V6 has a coiled cable; it looks like the one pictured at http://media.headphone.com/productphotos/large/0020550006_52...
Whoops, I guess I was just wrong about that. It was the only reason I bought the 7506 over the V6, but I guess I was misinformed somewhere along the line.
Re:Headphones for Hackers
by sliverstorm on Friday February 24, 2012 @05:45PM
(#3631458)
I have always read that the only important difference is more bass emphasis in the V6's as compared to the 7506's, which have a very flat response.
You're probably thinking of the V600 which has heavier bass and swiveling earcups for DJing.
Besides brand there are some other things that one should look at like the cost and also whether headphones offer a natural means of listening. Remember ther is part of your health that you want to check.
Wikipedia on the MDR-V6, MDR-V600, MDR-7506, MDR-7509HD, and MDR-CD900ST: http://en.wikipedia.org/wiki/Sony_MDR-V6