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
I would really love to hear the answer to this myself because I have been trying to find information on this exact situation. Can't seem to get many answers.
We sell the waveterminal. It's used with our professional test kits. I use the waveterminal on my PC. It's very good and I've had others buy it and exclaim it's the most fantastic thing ever. I don't know about it being that fantastic, but there is no comparison to the sound cards in my computer--it's in a totally different league. Unfotunately, I can't offer you direct comparisons to the other options you mentioned.
Thanks Dschea_32665. I know it's all subjective, but without the equipment for my own comparison, it's hard to know if spending my hard-earned bucks (graduate student) on various DACs would reap the rewards of improved sonics.

So far, my GMA Europa speakers has made the biggest difference. The SACD player made a nice improvement. Having it modifled also was a nice addition. The Cayin amp also improved the sound and dynamics; I had an old NAD receiver before. I've also heard an improvement with better interconnects.

Will adding an external DAC with my computer HD as transport and music jukebox improve the sound even more? If so, at what price point? What equipment is needed to have that "better" sound? For the buck, where will I hear the most noticeable improvement?
I have been doing research on this as well. The only way I could figure to get the information is to start throwing money at the situation.

So far I have used the the Monarchy Dip/DAC, Edirol UA-25 feeding a Mcintosh MDA1000, the M-Audio Transit, the Waveterminal, and the MiniDAC. (Also compared them to high end McIntosh CD transport - the computer won).

I set these up on two identical systems (one is mine, one a friends): Apple Mcintosh playing Apple Lossless files to DAC to Mcintosh MC1200s to Mcintosh XRT 28s.

The only real standout so far was that the Transit sounded BAD on several different Apple Macintosh systems, and the MiniDAC drops the USB signal about six times a day (Apogee says it is my computer). I will do more in depth listening next week.

The consensus seems to be that it is best to avoid SPDIF and toslink connections. Does anyone know of a high quality USB device that will supply digital output via an XLR balanced connection?
The Edirol is probably the best choice for iMac. An AES/EBU interface can easily be added to the Edirol with mods, as well as improving its jitter performance. Just a short cable hanging from it with a XLR connector attached.

BTW - Edumke - Did you try iTunes with the Transit with an iMac?

Steve N.
Empirical Audio
Manufacturer