Bob13013A lot of people have been recommending the vali or the O2. I've also looked at the fiio e10k which seems alright and a external sound card from creative.
What I am waiting for is my modmic to come in. I wanted to make sure I wasn't going to get static from my modmic through my onboard mic in. If I do, I'll probably have to look at an external soundcard.
Also, I'd say my budget is pretty flexible. I just want something to drive the AKG 7XX really well.
DABTPAI ended up going with the Fiio E10k. I was not planning on using my dac/amp for portability so I wanted some fairly cheap and got the job done. The E10ks are just that.
I think most amps will be able to drive these since the impedance is only 32 ohms.
NoveskeWhile the E10K isn't bad, you aren't driving the KXX to its full potential. The E10K only pushes about 200mW at 32ohm. You need something like a JDS O2 amp (613mW at 33ohm) at a minimum or preferably more to properly drive these.
I have the K702 65th Annies (which are very similar to the KXX) and went from Audioengine D1> Fiio E17> JDS O2> Fiio E09K> Schiit Asgard 2. I heard a very obvious sound quality difference going from the 200mW E17 to 613mW O2, and a lesser but still noticeable jump to the 900mW E09K then very little jumping up to the 1,000mW Asgard 2. There was more "depth" across the mids and fuller bass with the higher power amps.
The AKG K/Q7-- series is more current hungry than voltage hungry, so the 62ohm impedance is kind of deceptive. The sound quality scales up as you add power. I don't have anything over 1,000mW so I can't say if it scales well beyond that point.
I can also get them stupid loud on the measly 100mW Audioengine D1 at about 25% volume, but loud does not sound the same as the fuller/deeper sound from the higher power amps.
NoveskeWell there's this german studio electronics firm which offer a small module to fit in your own case if you are fond of fumbling: http://www.funk-tonstudiotechnik.de/SYMM-VERST.htm#Headmaster Regarding power and distortion it is - how to say that - beyond any criticism.