Is there a DAC that will handle FLAC, WAV, Apple Lossless, DSD, DXD, etc. at a price and quality that is competitive with high quality CD/SACD/DVD-A players?
That's a mighty ambiguous request, isn't it?

What price range? Which 'high priced' units do you consider quality?

Not knowing exactly, I'll assume you want a DAC which has multiple connectivity, inclusive of USB...and, do you mean to use strickly USB interface, or a sound card? The format of the music files isn't as important as is the error correction ripping, and using a lossless codec right up front.

There's a few DACs which will handle much of your request I suspect... that 'DSD' part though, well, I've yet to see a outboard DAC which processes DSD purely, without converting to PCM. There might well be, but surely not using USB. In fact I don't recall even one DAC which does DSD which is a process SACD uses... or any standard DACs which support DSD.

Finding 100% of what you seek in one device may prove quite interesting. I'd say it ain't available. 'Course I ain't the last word on it either.

My Bel Canto DAC 3 via USB only handles word lengths of 16 bits and sampling rates of 44K to 48K... convert that by up sampling to say 24/96 PCM and use a digital interface like AES, OR SPDIF, and the audio quality improves... a sound card is then required to accomplish that.

My sony SCD xa777 es, plays SACDs and supports DSD in the doing of it... but out of it's digital connections... only PCM data is produced.

Good luck
There is a DAC from Digital Audio Denmark called the AX24 that appears to handle all of these formats, but it is very expensive, and the interface seems to be very complicated. At the high price, there is no driving force for such a purchase. If a lower-priced device existed, then that would be interesting.
it sounds like you want to use a dac for a music server. if that is the case, any good external dac will do that. i don't use usb with my dacs, i use either a aes cable or coax cable coming from a jitter reduction device which is hooked up to my music server (wired or wireless). if you want to use a dac for sacd output, i think you are out of luck. as for price, there are quite a few dacs available that sound good from a few hundred $$$ to many thousands of $$$.
Just a note of clarification; a standard DAC (internal or external) handles the conversion of a digital signal to an analogue one. A DAC does NOT handle the conversion of a digital format file (i.e. .wav, .flac, .acc, etc) to a digital signal - that is handled by a computer or other device such as sonos, squeezebox, etc.

aside from expensive, high-end "all-in-one" solutions (Sooloos, Nova Memory Player, etc), one device doesn't do all these tasks. You still need something to convert the digital file into a digital audio stream. The nuance in DACs right now is what type of digital input you use (USB, Optical, I2S, etc).

Getting both D/A conversion AND file conversion into one device - free of jitter and noise with a short signal path - is the holy grail of digital audio we are all looking for.
Shazam, excellent clarification.

If you're running some kind of digital cable into a DAC (whether it's optical, coaxial, USB, whatever), then something has probably already converted the file format into the 1's and 0's that the DAC needs to create an analogue signal.

exactly. when lapaix described his thread above, it sounds like he is using a computer with itunes for some of his playback. the computer will read the digital file (apple lossless, mp3, etc..) and send the signal (in my case) the optical output of the macintosh in a digital stream that is compatible with any audio device, like a dac or even a receiver/preamp that has that input. same thing happens when a cd player reads a disc, it can read multiple different types of disc and it translates what is read to a standard digital output stream (sacd, dolby digital, dts, etc.. are different).