Ok yeah i meant lossy. oops.
BUT: I'm happy (at the moment) with the soudn quality from the mp3's. This thread kinda went on a tangent with the mention of amps.
What I was really after is whether the 650's have a more linear response than the 600's. Todd @TTVJ already confirmed my 590's would most likely sound poorer than either of these cans.
The difference I am after, without changing amp (just yet) is for my mp3's to sound better balanced. As they did with my 495's. You are ALL right when you say it will show up any deficiencies in the mp3s. The 495's were already doing that
But I was happy with the quality of 99% of my music and happy with the balance. It's just that my 590's, which I thought were going to have that same kind of Senn "balance" are junk. They are severely disappointing even compared to the 495's!
And I read the 600 have a slight bass/treble boost character to them and can be slightly grainy. So I am hoping to confirm the following:
1) The mp3's will sound as good as they did with the 495's and definietly better than my woofy and harsh 590's.
2) The 650's will be less grainy than the 600 (I've read that in a few places now)
3) The 650's area worthy purchase for future proofing - Next purchase will be an amp.
Hopefully that's cleared things up! Thanks for all ur help so far.