Upsampling the way to go? ?

Sean T., sorry to second-guess, but your first sentence strikes me as being just a *little* bit confused itself! :-) Tim and I don't disagree about what upsampling is (as opposed to increasing word length), we are just, again, a *little* confused about how it happens!

You say the upsampling "...uses the extra samples to interpolate." That seems backwards to me. Wouldn't upsampling have to *use* interpolation to *arrive* at those "extra" samples? Then the DAC would use *all* the samples, including the "added" ones, to reconstruct the wave? Or, yet again, do I "misunderestimate" this process completely? My new MSB Gold Link DAC mentions in the manual that "oscillators" are used to upsample the signal. My dictionary defines "algorithm" as any mechanical or recursive computational procedure. "Recursive" is defined as descriptive of a mathematical expression like a polynomial, each term of which is determined by applying a formula to preceding terms, or of the formula that generates the successive terms of such an expression. The definition of "mechanical" that would seem to apply in the case of an oscillator is "governed by mechanics". Sounds simple, doesn't it?

The Gold Link comes with two oscillators to choose between, and seems to sound better on CD's with the upsampling set to use the one at 132KHz instead of 96k, which is recommended by MSB since 132k is an even multiple of 44k. The math has got to come out better this way in a "mechanical" process, no? Still confused, Z.

Zaikesman ... I think you're being a bit pedantic. Increasing the sampling rate is the goal, and it is necessary to have some sort of interpolation in order to be able to assign a value to those new samples. One cannot interpolate without increased samples, one cannot increase the samples without interpolation of some sort.

Word length is a completely separate thing.

Using a multiple of 44kHz would seem to me to make the job of the upsampler easiest, especially with linear interpolation, since the original samples are preserved ... but I think a non-multiple could also be made to work, albeit with a bit more complexity.

Of course oscillators are used ... an oscillator is no more than a clock ... so they are saying they have extra clocks within the DAC ... I'm guessing from this that they are stating that they generate their own clocks at the higher sampling frequency instead of deriving them from the (potentially less accurate) digital source signal. Any reclocking DAC does the same.

I try to describe things as clearly as I can ... your response seems to be worded in an deliberately obscure way. Is there are reason for this ?

Actually I think Sean's (the other one) original post was spot on. The format is not the problem .. it's the implementation. That said SACD is a superior format, if not yet a superior implementation.

No, Sean T. - pedantic is *all* I'm being! Sorry if my writing seems obscure, it's not deliberate. I just tend to write densely (or is it that I'm just a dense writer?!).

Or could it be that maybe you're just not closely reading my posts (certainly your perogitive)? Your first three paragraphs above essentially reiterate things I believe I've already stipulated throughout my posts on this thread. Thanks for trying to be of help, though. :-)

Zaikesman ... your accusations are quite valid ... I usually don't have much time to do a thorough read. Re-reading the thread we are in close agreement.

Thanks also to dan2112 ... this white paper was very interesting. Perhaps if I get the time and money I'll have a listen to an upsampler. However much SACD is theoretically better I'm certainly not in the mood to replace several hundred CDs, especially since many were (unfortunately) digitally recorded, probably at 44kHz !

http://www.dcsltd.co.uk/papers/aes97ny.pdf

Anybody interested in reading about the results of my auditioning of my new upsampling DAC against my reference that I referred to above, should be able to see it shortly on the forum in a new post titled Upsampling Put To The Test (hopefully it'll show up there later today). It's a long article though, don't say you haven't been warned... :-)