skip the maudio av40s...i bought a pair refurbished and they quit on me within a year...sound quality was pretty crap too.
Agreed. I have an old pair of the discontinued DX4's that are great so I suggested the AV40's to a friend of mine who was putting together a PC system. Pretty disappointing sound compared to the DX4's and he was having issues with one of them in about 6 months. M-Audio still makes some decent monitors but you have to go up to at least the BX series and at that point there are other contenders to consider.
As far as an outboard DAC, I think that's a very good idea as most of the ones built into soundcards aren't very good. In addition to the Audioengine D1, I'd take a hard look at the FiiO E17. I got one a few months ago to replace a NuForce uDAC-2 (ugh, what a piece of crap) I was using with my laptop and found it to be a great DAC/headphone amp. Doesn't have the RCA output like the D1 but it does accept a S/PDIF input in addition to USB and LINE. It can also be used as a portable headphone amp with its built-in battery.
I was looking at the Fiio e17, but the lack of RCA outs bothered me. How would I drive the AudioEngine A2s from the DAC/headphone amp - with a miniplug? Is the quality worse or better than using RCAs? The big plus for that machine seems that I could use it portably as you mentioned while I can't really do that with the Audioengine DAC> For the Fiios I wonder if you can use it while it is charging, or if you only run it off the battery. I was settled on Auioengine D1 and A2s, but am open to ther suggestions. Anyone else??
Funny you mention all of this; I just received a pair of the Audioengine 2 speakers yesterday. They sound really nice! Much, much better than I expected.
If you want to run a D/A into them, there are both miniplug and RCA inputs to the speakers. I would run source > D2 > RCA inputs to the 2 speakers.
I have a Pure i-20 iPod dock (which has an internal A/D - not a good one, however), so I'm planning on running the Audioengine 2 speakers with two inputs: using the RCA inputs for the Pure and using the miniplug input for my computer. While the RCA may theoretically have a better sound quality than the miniplug, there is a good chance that you would not really notice the difference when using the Audioengine 2 speakers. They are good speakers, but probably not THAT good to pick up differences in input type.