Up and Over sampling EXACTLY the same thing

Just ordered a Belcanto DAC2 – and now this! Are they really the same? I doubt. My imagination is that oversampling is a linear interpolation from one sample to the next, in 4 or 8 steps, while the interpolation from upsampling is of a sine-wave shape created by coresponding algorithms. Well, I can't pretend that I'm right on this.

Anyway, it's obvious that a conversion from 44.1 to 96 or 192 kHz isn't just oversampling in the mentioned way; there had to be 88.2 or 176.4 kHz. It's first of all a sampling conversion. I don't know if there's any advantage from that, but it surely is different from common oversampling.

And according to German magazines it sounds clearly better than with normal CD-Players' (oversampling) techniques. The reviews refer to DCS Purcell/Delius + Elgar, Chord DAC 64, Electrocompaniet ECD 1 and Musical Fidelity A 3-24. Especially the DCS combo is said to be very close to the hi-rez formats. If there is a possibility to switch between upsampling and non-upsampling, the difference is clearly in favor of the former.

Hellosimplymusic, I agree that the misconceptions regarding up/oversampling have reached critical mass and that the marketing hype will likely continue.

I wouldn't say I understand the technology well. I am not an EE specializing in digital design, although I am an engineer. That said, I do not think this is conceptually difficult to understand.

Judit, I wrote that to mean that I feel purchasing a piece of equipment based on the marketing hype is not likely to result in sonic satisfaction. The component may sound better, it may not as well. Our ears will ultimately determine our satisfaction, notwithstanding certain short-term psychological effects (eg. this "should" sound better affecting it "does" sound better -- not sure what this phenomenon is called?).

I am not familiar with the VHS/Betamax story, but I have heard it to be very interesting. Something along the lines of Betamax being technically superior, but marketing and timing resulted in VHS winning out. Is that essentially correct?

Ultimately, I think we all want better sound. Some may be quite content with knowing their ears tell them it is better while others want to know how/why as well. For me, I want to hear the differences for myself and know how/why also, probably the engineer in me coming out. But, no matter how interesting I find the technology, if it doesn't sound better I don't want it. And BTW, I don't consider "upsampling" new technology. Better filter design, yes, upsampling, no.

I have not heard any of the new formats (DSD or 24/96). They likely offer greater "potential" for sonics, but without a sizable library of software and clearly better sound, I probably will stay on the sidelines. I also have hope that significant improvements in Redbook CD will continue as long as 16/44.1 software is still produced. This, I believe, is good for us all!

Martian,

If you like how the Belcanto sounds, what's the problem? The sound is the most important part, at least for me.

Upsampling and oversampling are indeed the same thing. Both are sample rate converters. Both increase the number of samples by some factor (2, 2.18, 4, 4.35, 8, or whatever). Both will need interpolation to assign a voltage (amplitude) value to the newly created samples. Although a separate process, both may increase the word length from 16 bit to 18, 20, or 24 through the appropriate use of dither (basically white noise). Both may use a dac of various resolution (18/44.1, 24/96, 24/192 or whatever).

As Charles Hansen (research director for Ayre) said in the article I posted above, "Upsampling and oversampling are the very same thing and anybody who tries to tell you differently is misstating the case... And there's nothing unusual about putting two digital filters in a row -- virtually every digital filter is a cascade of 2x stages, because it costs less than accomplishing the entire filtering process in one go".

The reason why turning off upsampling on a capable player changes the sound is that you are taking one of the digital filters out, Particularly if it was designed to utilize the computing efficiency of two digital filters, it is likely to sound worse with only one. Again, Charles Hansen: "upsampling almost always makes a difference, and it can make an improvement".

In the end, it's the sound that matters. If it sounds better and the mfg happens to market using the "upsampling" hype, then fine. I do appreciate mfg's who talk straight about the topic though and if two products sounded identical (or maybe I should say the final subjective value I assign to the two products are the same), I will award the straight talking mfg with my business. That's just my philosophy.

Germanboxers, The VHS/Betamax story is much more interesting. As I recollect: The original betamax was a superior medium for encoding audio along with video. However, in the best spirit of technical competition, a multiplexing scheme was developed for VHS that kept them in the running quality wise. The format wars ensued with better quality being produced at every iteration. This was great reading back in the days when people were deciding what type of machine to buy. Ultimately Betamax lost out due to SONYs shortsightedness with regard to exclusive patent rights.

BTW, Judith, Beta (super~) was used in advertising all the same. Better of course, than vhs with good enough resolution to air, and cheaper to use than 35mm.