I'm basically in your situation, except that I've already bought and sold a bunch of stuff trying to look for something I'll be happy with in that price range.
Getting a separate dac and amp sounds ok in principle, but the problem is that the cheapest decent amp would be something like the Matrix M-Stage, for like $225-$250 shipped. The problem is that that gives you less than $200 to get a dac, and that pretty much leaves you on the level of the uDac which is not that good. I think the combo units offer better value unless you're spending over $750 or so.
The Yulong D100 looks like a great unit - some of the biggest reviewers here own it and love it, I don't think there are that many returns, it's just a case of those who do writing about it and skewing the search resultsand no, it never sells for $300 - just that one guy, and I actually tried to buy it, and he had already sold it in like 10 seconds. So that was wildly underpriced. The $380 guy is in australia and shipping is like $70 to USA, which is why it hasn't sold long ago. Most people just buy them new. I think that's honestly the best solution by a ways. But its at the top of your budget. The lower priced Yulong dac/amp has gotten a good review in Headfonia:
http://www.headfonia.com/the-new-recommendation-the-yulong-u100-usb-dac/
Another excellent solution is the CEntrance DacPort. It's $399, but can (rarely) be found for a little less. It's a fantastic little dac/amp, that does wonderfully with IEMs and lower power headphones. I'm sure it would have enough to drive your phones, but it wouldn't be the most authoritative solution, since it's running off of bus power, and since you don't need it to travel, I think you'd get a better deal with AC power. I just bought one, I love it, but I have JH13s, which require infinitely less power than your headphones.
The Matrix mini-i is a possibility, but I don't haven't read enough about it to say. Most people that have it like it, but it's usually their first dac/amp, so they don't have much of a reference point. I don't recall reading many reviews where it's compared to better stuff.
The littledot dac/amp is like the matrix mini-i - I just don't know enough about it to say, but it's likely quite decent.
The Nuforce HDP or HD is supposedly much like the DacPort, but with a touch more power. So that could very well be ideal for you. Many love it, and I've never read anything seriously bad about it. Can't you buy on new on amazon.com and return it in 30 days if you don't like it? I didn't say that.
Finally, Audio-Gd. I've owned a Sparrow B 8740 and traded up to Sparrow A 8741. I love it. It sounds gorgeous. Kingwa told me its basically very much like the NFB-12. I think the Audio-Gd products have a lot of fanboys because, quite honestly, they represent serious value for the money. I seriously doubt any DAC/AMP can come CLOSE to the NFB-12 at $200 ($250 with shipping.) That said, I have no idea how it compares to the nuforce or anything else that's twice the price. I do know the Sparrow A is very, very close to the $400 DacPort: so much so I can't decide which to keep and which to sell. I had wanted to try the NFB-11, but I bought one three months ago and waited and waited and finally got tired of waiting last week and cancelled my order. So that's audio-gd's big problem right now - the NFB-12 and some other products are such huge sellers that they incredibly backlogged, and won't have those units for MONTHS (I know, because I just asked.) Also, since they're brand new, and people have waited so long to get them, I doubt you'll find anyone selling a used NFB-11 or NFB-12. Frankly, my top pick for someone just starting and wanting the biggest sound for the least money, I'd say to get a used Fun or Sparrow A. The Fun if you can stand having something that gigantic on your desk, the sparrow if not. Used, you'll find them for $150-$200, and they will sound incredible.
I've been looking to trade up from my Sparrow A, and my biggest problem is that I haven't heard anything better for $500, and I'm spending that much over that, I already know what I'd get - the balanced Audio-GD NFB-10WM at $850. The only thing I'm considering getting right now is the D100. If one were on sale for $350, I'd buy it in a heartbeat. But for $450, I'm not sure.
Edited by AVU - 4/29/11 at 12:42pm
