What is the best sounding DAC at $2000-$4000?

This one only has a USB input so not sure it would work for you, but it's also "only" 900 bucks and seems to possess many of the qualities you're looking for if you put any credence at all in reviews (I know, I know). I think the reviewer bought the review sample, which at least says something, and I believe it was also positively reviewed in Stereophile. I thought the Ayre recommendation was a pretty good one too if you're looking for a smoother, more analogue kind of sound. Anyway, best of luck.

http://www.goodsound.com/index.php?option=com_content&view=article&id=249:wavelength-audio-proton-digital-to-analog-converter&catid=56&Itemid=37

Getting the PWD MKII would offer the additional benefit of network streaming if you get the bridge - this will sound better than USB. I would get one used and give it a whirl.

Thank you very much for your suggestions because truthfully that is all I can ask for because I do understand it will vary from system to system. I have heard the Weiss and Auralic on my system and on my friends system; truthfully I was surprised at how close they sounded because they are not close in price. I will look around my area and try and find an Ayre dealer and a couple of other DACs that were mentioned.

Should I step up another $1000 and look at more expensive DACs or does it make that much of a difference? According to several friends of mine you will get in to the law of diminishing returns.

Hottmale

you owe to yourself to audition the bel canto dac3.5 + vbs power supply. Take an extra cash effort but a huge leap in sound. I myself auditioned it just yesterday and i'm about to close the deal.No usb connection but simple solutions to bridge that.

Given your budget criteria I would listen to a Bryston BDA-1. Class A analog outputs make this very musical and smooth sounding. It has USB inputs as well as coax, AES/EBU, Toslink.