Well, I don't know, I just let my good apple computer handle these conversions. I think the ones with linux and the ones with whatever bill gates is calling his OS this year may have even better options (did I just type that?

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Note: all my comments below apply to what we do to listen to music at home. What needs to be done in a recording studio or a music production environment may have very different requirements. Once the music is finished however there is a simple downsampling algorithm that can be used to bring things back to the usual bit stream used in good ol' CDs.The basic problem is that Frank builds his stuff to last 30 years (sorry if I'm shortchanging you there Frank). Do you expect the HDMI cable to remain the same for 30 years?
One thing that I expect to remain the same for the next N years (N being the finite number of years left for humanity) is the theorem credited to Shannon whereby he established that a sampling rate of 2F is sufficient to reconstruct all the information in a wave up to a frequency of F. Hence once we had a handle on sampling rates of around 40 khz, we had all we need until we do an upgrade on our ears.
(btw that WILL totally suck, the day little humans start coming out with 100 khz ears, 20th century music is going to sound awful to them (and I doubt they'll care much for snap crackle pop either).)So as far as the frequency domain goes I think we're covered. As far the amplitude (i.e. volume, loudness, etc.), supposedly there is some improvement in going from 16 bits to More bits. Now in principle 16 bits gives you 96db of variation. Do you think you live in a listening environment where the noise floor is down 96db? Now, granted, if you are flying out in space with Hal and he makes a vacuum bubble around your listening chamber then maybe you can get such a noise floor, but I suspect that even by breathing we are already disrupting things a bit.
I think that realistically even 40 db is probably enough, once again due to various real-world constraints on the diminution of noise. The one place where you might have a fighting chance is with spectacularly excellent headphones, but then where does the bass go? And besides, the best headphones are open anyway.

The upshot of all of the above is that there is a hell of a lot of stretching and reacommodating and retooling and rewhatevering being done for the sake of hearing better at 40 khz and hearing better the difference between 119 db and 120 db down from maximum output. Couple that with the large mountain of proper math standing between any one of us and the spec vomiting marketroids who insist that our minds be linear in the "bigger is better" so as to be shoppingest and wastefulmest and pollutingmest and toxicmest and deadliest, and basically I come to the conclusion that I'm getting mine pulled for all the wrong reasons.
Oh, I almost forgot. Digital storage goes up by several factors when you up the bits. Currently you can fit 1500 lossless CDs on a 500 MB hard drive, which is a pretty respectable personal music collection and easily portable with a 2.5" hard drive and a USB cable (say); flash drives go accordingly. All of the above becomes more difficult or even eventually practically impossible as the individual music files become bigger or re-encoded to the latest-n-bloatiest.
Final upshot--what really makes a difference is a great analog stage feeding a great preamp feeding a great amp feeding a great pair of speakers.
So to bring it back to Do, I'll just let the computer or whatever they'll be calling the codec containing gadget in 20 years handle these tasks, and just get a steady bitstream of 0s and 1s to the AVA Dac and enjoy much better music than almost anyone else I know.
