The Denon model would be an excellent choice IMHO.

+1 for the Sennheiser Amperior then.

relax. I just offered my two cents. And I'm happy that you can think of multiple better cans than the Momentums..... in your opinion. 

If your willing to buy an amp, just spend that extra $100 on some headphones that can be driven easily by an ipod/iphone/etc. I've got the Sennheiser Momentums which are typically $350, but you can find them for $300 if you shop around the internet a bit. Great cans, easy to drive, no complaints. 

*Portable, whoops. In that price range try ALO Audio's International Amp/Dac of the Fostex HP-1 Dac/Amp

I'm assuming this is a desktop and not a portable set up. If that is the case check out ALO Audio's PanAm Dac/Amp combo. It is $500 and generally receives great reviews.

that depends entirely on how much your willing to spend. $300, $500, $1,000+?

If you want a closed can +1 for the Momentums. I've owned mine since last October and absolutely love them. Comfortable, great sound signature, ample bass, pretty much the whole package.

For around $350 if your looking for a standalone amp and not an amp/dac combo I'd go with either ALO Audio's The National or RSA's P-51 Mustang. 

The dac component inside FiiOs will not work with iPods, iPhones, or other phones as an fyi. If your looking to use an external dac on the go with an iPod or iPhone you'll need something that is Apple licensed such as the Fostex HP-P1 (dac/amp hybrid) or the cypherlab's algorhythm solo...

If your looking for home use get a dac/amp combo. What to get depends wildly on your budget. A great combo for a reasonable price is ALO Audio's Pan Am, it is $500 I believe.  Schiit Audio also produces dac and amp components. 

I'd get the duet, people generally say it has a lower sound floor than ALO's amp + it is $50 cheaper. Either way though you won't be disappointed, both those amps are designed to compliment the CLAS well. 

If you can reliably hear the difference and identify a lossless format from 320 kbps in a double blind test I'll eat my shoe.   Nobody is claiming that lossless and lossy formats are inherently the same, the argument is that the human ear cannot detect the differences between those two formats...

It has nothing to do with their timeline, I find the HD800 to be a superior headphone in virtually every facet to the HD 650 in my experience trying both sets of cans. I'd also like to remind you that this is a portable headphone amp thread, which the Zana Deux is clearly not.   Your...

The Sennheiser Momentum is a great option, in that price range, however the drivers are less than 50mm, not that it hurts the sound quality.