[skaizen]

Hi, I've had my hd 598s (driven just by my mac 2009 and an onkyo receiver) for 3 years, and decided it is time for an upgrade, however I'm still pretty unsure what to get. What im looking for in my upgrade is a pair of headphones that is flat, reveals lots of detail, has a wide soundstage, and is very clear. The type of music i like to listen to is rock and classical music. My budged is less than $500 (including amps and such). Any recommendations?

 

[KG Jag]

You're in the realm of mid-fi former flagships (or their successors)--several very good cans, but not with everything on your list.  You'll have to pick the flavor of ice cream you like best.  Consider the HD 600, DT 880 and Q701.  See:
 
http://www.head-fi.org/t/634201/battle-of-the-flagships-58-headphones-compared-update-audeze-lcd-2-revision-2-6-4-13#user_DT880
 
http://www.head-fi.org/t/634201/battle-of-the-flagships-58-headphones-compared-update-audeze-lcd-2-revision-2-6-4-13#user_HD600
 
and the similar but not quite as good to my ears as the Q701 (which a bit more bass and more natural treble)--
 
http://www.head-fi.org/t/634201/battle-of-the-flagships-58-headphones-compared-update-audeze-lcd-2-revision-2-6-4-13#user_HD600
 
If you only needed to add an amp, I'd recommend the O2.  However since you listen to digital files, you'll need an amp/DAC (paired with good quality music files).   Others will have to help you on that because my serious music listening is fed by various quality disc players or a turntable.

 

[jodgey4]

The Q701's come to mind from your description, which would pair very well with an Audio-GD NFB-15 DAC/amp, which could all be had for under budget. Clean, fast, open, neutral sound... If a bit bright to some. The NFB-15 is clean and detailed with slight warmth. There also the slightly warmer K712 if you want to stretch the budget a bit. I've reviewed the two along with some others... I'm on my phone otherwise I'd post a link. HD600's would be a logical step up, with great tonality and warmth, and you could run them from the receiver most likely to great effect.

 

[fabio-fi]

The Shure SRH1840 come to mind but they are $500 in the US. It leaves no budget for additional audio gear :\