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

Bhobba: I purchased a Metrum Octave a while back and love it. I am running Pure Music in my Mac Mini. I purchased a Mach2Music HiFace 2 USB/spdif converter. While playing music into the HiFace 2, I would here "clicks" and "pops" during playback. I ultimately returned the converter. Did you ever experience this with any converters? Do you have any idea as to what I may have done wrong?

Audioengr: INSTRUCTIONS?!?!? INSTRUCTIONS?!?!? Are you kidding me? Mach2Music is without a doubt the most user UN-friendly company I've ever dealt with. There were no instructions with my converter. Also, emails take months, yes, MONTHS to get responses to. I couldn't find any information about how to properly set up the converter. I've asked this earlier: How do you set the buffer size larger? I am in full support of computer audio and I believe it can surpass cd players if properly set up. However, in order for hard drive based digital to work for the masses, THERE MUST BE MORE INFORMATION AVAILABLE TO THE GENERAL PUBLIC REGARDING PROPER SET UP SO GUYS LIKE ME DON'T HAVE TO POST QUESTIONS IN AN AUDIOPHILE "CHAT ROOM" TO GET ANSWERES. I've been saying this forever. This thread is the very first time I've ever heard the word "buffer"...ever...anywhere. Why? This is exactly what I'm talking about. This information should be available to everyone buying a device like this converter.

Audioengr: I never received instructions for the HiFace2. When I tried to download the owner's manual, every page was blank. Do you know how to do it?

Thanks Almarg, but the same thing happened. Nothing but blank pages. I have a Mac. I don't know if that has anything to do with my inability to view the pages. Also, I sent an email to Mach2Music a few months ago. After a couple of months they finally replied back but mentioned nothing about a buffer. Why didn't they say anything about it?

Again, Audioengr: How do you increase the buffer size?

Almarg: Thanks again but I couldn't find anything. I'm using PurMusic for playback. I went through PureMusic's menus in "preferences" and couldn't find anything about buffer size. I'm not that knowledgeable about computers and software. I don't want to be a pain here, but can someone describe it step-by-step?