DACs: Airport Express vs waveterminal vs mini-dac


I know this is impossible to quantify, but with a good stereo system (Cayin TA30 tube integrated amp & Green Mountain Audio Europa speakers), what's the magnitude of difference using the following dacs?

Airport Express (I already have the AX, and can connect it to the integrated amp with RCA's [analog])

Waveterminal U24: computer to USB to waveterminal to amp (waveterminal does the DA conversion)

Inexpensive DAC like ART DIO with waveterminal: computer to USB to waveterminal to ART DIO to amp (ART DIO does DA conversion)

Apogee mini-dac: computer to USB to mini-dac to amp

Other?

What's the best bang for the buck?
mschamberlin3865
Thanks Edumke. It looks like I will be purchasing a waveterminal in the near future. Very cool. My DAC will be much more modest. However, I don't know anything different so I will still enjoy the upgrade.

If you can recall or could do a quick test, do the Edirol and the Waveterminal have pretty much the same quality when passing the signal through to the DACs? They are about the same price, but if one is definitely better than the other I would pick it.

If they are similar, I like the Waveterminal because it is smaller and doesn't have extra features I don't need. However, quality comes first.
Dshea_32665, I have set up two nearly identical systems. One I set up for my friend, the other is mine. The only difference is that I am using the Waveterminal, and he has the Edirol UA-25.

Since the systems are set up miles apart, I cannot give you a side by side comparison, but after hearing both extensively, I would say that there is no difference.

What is fascinating to me is the difference between the MiniDAC and the McIntosh MDA1000. Switching between the two, the music sounds much different. The MDA1000 does just what they advertise; the music is smoother, less harsh, much more pleasant to listen to for extended periods. I have read numerous reviews that describe McIntosh as "musical", and that is precisely it.

Having said that, the MiniDAC might be described as ultra clear.

Both are fantastic. If I had to pick one, it would be the MDA1000.
For passing the signal through to my DAC, I've been using the waveterminal and like it a lot.
Great guys thanks. Off to ebay to buy a waveterminal. Then I can start thinking about the higher end DAC. I am using a portable AOS Piccolo DAC which is a fantastic unit for the money, but it is nowhere near the price range of those being described here.
Having some trouble getting my PC laptop to talk to the AirPort Express....

Looks like I will have to cut it out of the case to mod it - no fasteners.