x2 on whether an iPod / Nano would benefit from a quality external DAC. Up 'til now, I just run an L3 line-out jack from the Nano into my amp of choice. If I could improve the signal further, before sending it to the amp, hey, that'd be great!
Evshrug - Thanks for the tip on the iDo. Half the price of the iStreamer, and yes if it will work with an iPod classic then it'll work with the Nano. They are the same things, just different sized packages. And I love NuForce, there stuff is always well made, if not "the best" unit. And their prices are always really fair for what you get.
Ashade & Chicolom - Have you guys heard the K/Q 7xx with a tube amp? The big reason I didn't keep my, say, O2, and shy away from solid-state amps in general with my K702 (and will with my Q701) is that they highlight the analytical nature of these cans, and can introduce some harshness in the upper end. But any tube amp I've ever used them with has alwas solved this issue. (The M-Stage also didn't have this issue; it sounded more "tube like" but had a tendency to shorten sustain and mask detail, things any quality tube amp I've used - including even the Starving Student hybrid - never did).
ThurstonX - yeah, that is a great review from NA Blur. But I'd love to see him try the modded Q, and see if that changes his conclusions at all. As I've mentioned: personally, I'd love to have the K712. But at double the price, I'm already halfway to a T1, so at that point I'd rather keep saving and just get a T1. Or, as we'll see, a K812!
Evshrug (again) - dude, I'm drooling all over my nice sweater waiting for this Q vs modded Q vs K712 review! I suggest you order Chinese takeout, call in sick, give your significant other a gift certificate for the local spa, and get to work on these comparisons!
Big Bird - I don't mean to rain on any parades, and I might be wrong, but... I don't think any DAC/amp combo in that price range is really gonna be much good. Especially with a Q701 or any K7xx model. They are notoriously difficult to drive!
My advice to you, would be to order a custom CMoy amp from BioScienceGeek (BSG for short around here) off eBay. His amps are the best portables I've ever heard, personally. Better even than NuForce's great stuff. And they're dirt cheap - like $50 ish. You can also tell him exactly the headphones you'll be using, and the type of music and you're mainly into, and choose the case. He builds to order. The one I have is the best sounding amp period with my Etymotics, for example. I find it comparable in quality, (if not sound signature), to my $800 Glow Audio amp! And the 9-volt battery option makes it super portable and convenient too.
Later, when you've got some bucks together, invest in a great DAC for your Mac ($200 - 250, or the new Glow Audio one at only $125), and then later a super amp that better matches the demands of the K/Q headphones, which are demanding and need a pricier amp. The Matrix M-Stage is a great start for $200 used / $300 new, and then up toward a Schiit Lyr ($450), or Garage1217 Amber ($300) or upper-end tube amp like a Woo Audio 6 or a Glow Audio Amp One ($700/800).
I find, and I think most people here would agree, it's better to sink money into just one quality component and move up slowly, than to spread money out over several lower quality units. Especially as the Q/K7xx are so demanding and picky with amps.