@udit , quid = pound.
Thanks everyone.
@ gannu, 595 are low impedance (50 ohm) - have a higher sensitivity than other phones, and can be easily driven with a low powered headphone amplifier, while on the other hand, 580/600/650 are 300 ohm and require a lot of power to be fed in to sound good, and essentially require an amplifier to drive them.
I had the 580s before, but I was not a big fan of the laid back sound stage, and hence opted for something livelier and easier to drive this time, without having to invest in an expensive amplifier.
The EMU 0202's headphone amp has enough juice to drive the 595s optimally.
And oh - I forgot to mention than they are fantastic ! The bass is super quick, quicker than 580s, but less deeper, from what I remember. I find the mids a lot better than the 580s.
Maybe it needs to be broken in, they have less than 10 hours on them atm.