Up and Over sampling EXACTLY the same thing

Wadia oversampling advocating:

«...Any advantage that can be claimed for a rate-conversion system can equally be achieved in a sophisticated over-sampled system such as the Wadia DigiMaster.»

I can follow you. But at the same time it's clear that the interpolated curve resulting from an upsampling (non-integer sample-rate converting) system isn't identical with the curve from an oversampled interpolation – after smoothing by the low pass filter. Though we can't say which one is better or more adequate, there is a difference. It can also be deduced from the reviewer's (Andrew Harrison) judgement, which btw. clearly favors the «upsampling» dCS against the «oversampling» Wadia. No deciding argument, of course, due to the very different devices.

Interesting points:

Sony only quit making Betamax players THIS year (2002).

Also, the Ayre CD player upsamples to 1.4112 MHz which is more than any other player that I can think of off the top of my head.

The Ayre player does sound fabulous though.

See my review of the Ayre CX-7 here at Audiogon.

KF

I'm going to try an isolation transformer to my CDP. Probably a more effective tweak than all this "up" and "over" hype.
Jon Risch has some interesting designs at his geocities site. No toroidial transformers, use EI (?) transformers instead..

This is interesting. Despite Wadia's previous efforts at dispelling the marketing hype of "upsampling/oversampling", they now have embraced it. (See quoted text below)

Or have they? They use the words "upsampling" in describing their process, but they don't "upsample" to 96kHz or 192kHz (non-integer or "asynchronous" up/oversampling). They actually use a 63X (~2.8MHz) oversampling. Is Wadia being disengenuous now or are those (mfg's and reviewers) who have been touting "upsampling" as something new and fundamentally different the ones who have been disengenuous?

I actually applaud Wadia in this. They have made efforts to inform the public that up/oversampling are the same, but it clearly has not worked. Plan B: Give up trying to point out the marketing hype and dilute it by embracing the terminology. If every mfg uses the term "upsampling", then is there any marketing advantage by touting it? Not a bad plan I suppose.

BTW Martian, Wadia use a 12th order polynomial spline curve fitting to interpolate the extra data points.

Wadia Technical Bulletin, March 2001: Up-sampling and Wadia Technology
Digital up-sampling has been getting a lot of attention recently, and for good reason: up-sampling can provide tremendous sonic benefit. At Wadia we have been incorporating patented, high-performance synchronous up-sampling systems into our CD Players and Decoding Computers since 1988. We welcome the new attention being paid to up-sampling and would like to explain the technology behind it.

What is up-sampling?
Up-sampling is the process of mathematically generating digital samples to “fill in the blanks” in a digital data stream. Up-sampling increases the digital data rate, reducing the demands on the analog filters used to smooth the signal during digital to analog conversion. Well-executed up-sampling can have a dramatic sonic benefit, resulting in a more realistic and natural musical presentation. However, up-sampling cannot somehow magically recover information not captured in the original recording.

Can up-sampling convert a CD into 96 kHz?
Some products use asynchronous interpolation to increase the data rate from a CD to 96 kHz or 192 kHz. While this process does increase the number of samples, it does not recover any additional information that would have been captured during a true 96/192 kHz recording. In fact, asynchronous interpolation discards the original CD data and can actually reduce the clarity and detail of the original recording.

Why is Wadia’s DigiMaster up-sampling better?
Wadia’s patented DigiMaster system, by contrast, uses a synchronous interpolation process to preserve the entire original signal and provide up to 2.8 MHz data rate – almost 30 times the data rate of 96 kHz up-sampling systems! The DigiMaster system uses 12th-order polynomial Spline curve fitting to generate up to 63 new samples for each original sample. Music lovers and audio reviewers around the world have agreed that Wadia’s innovative up-sampling process realizes the most compelling and engaging musical performance available.

What is the future of up-sampling?
Wadia has continued to refine and improve the DigiMaster system for over 12 years, expanding the possibilities for high-performance digital audio decoding. We firmly believe that consumers who desire the most advanced up-sampling technology in the world need look no further than Wadia.

«BTW Martian, Wadia use a 12th order polynomial spline curve fitting to interpolate the extra data points.»

Sounds good. I don't know exactly what it is (just know their «spline» low-pass filter), but it sounds like the famous sine-function interpolation – which I've always associated with Wadia and also my Theta Pro basic II, BTW.

(Wadia:) «...asynchronous interpolation discards the original CD data and can actually reduce the clarity and detail of the original recording.»
I would'nt expect any other statement from them ;-) But obviously it CAN also occasionally open new sonic horizons... [/euphoria off]