I'm a moderately old guy (early 50's) ... and have had reasonably decent hi-fi gear, but not what you'd really consider super good. Currently I'm using an NAD Integrated amp and a pair of B&W601's.
After browsing Head-fi I decided to buy a decent pair of headphones ... after a bit of research I bought DT990's (250ohms). I chose the 990's based on reviews, comfort and a very reasonable price.
For the past few weeks I've been playing them with the NAD amp. Two sources -- a cheapo CD player, and my MacPro quad core with the speaker out connected directly to the AMP (No separate DAC). I'd say I was modestly satisfied ... it was "nice".
Last week I decided to go a bit further, I ordered a NuForce Icon HDP Amp/DAC. I hooked it up to the Mac and have been listening for the past couple of hours. I can't believe the difference. The clarity and detail are amazing. As a test I alternated listening to two rips of the same song, Liz Wright's "Trouble". One was a 128k MP3, the other was Apple lossless. Huge difference.
I'm not sure if the big improvement in quality for me is more the DAC or the dedicated headphone amp in the Icon HDP ... but I'm very impressed.
I hope this isn't the start of an addiction.
