Greysquirrel; I'm no expert here, and I've had some of the same questions that you do. From reading, I've learned that upsampling and over-sampling are not the same thing. Upsampling adds dither, ie it interpolates between digital bits and then adds "sound" based on an upsampling algorithm via a DSP chip. This serves to make the digital data stream more continuous, ie more analog like. Analog meaning a continuous sound stream as opposed to the bit stream of digital output. Over sampling does not add dither or do any interpolating. Maybe Carl can help us out from here. Cheers. Craig. |
.... I should have added that over sampling is just used to increase the accuracy of reading standard 16 bit 44.1 HZ CDs, but it adds nothing to the digital output stream. Craig. |
Hi Greysquirrel-- excellent post, and thanks. Finally an answer to the oversampling versus upsampling question from someone who really does know. And I now admit that my original perception, that the two were different, was wrong. You may be interested to know that I emailed Theta Digital with essentially the same question. I got a reply from their Customer Services Rep. (not an engineer or designer); the Rep. asked their digital designers, and they flatly told him that "over-sampling and upsampling are the same thing", but implementation techniques vary. Cheers. Craig. |
I also emailed Madrigal Audio with the question of upsampling vs oversampling. I think it's fair to say that Madrigal also makes some pretty fine digital products, and I have their ML 37 transport and ML 360S DAC. Their response-- from Customer Relations: "We're actually about ready to post a position paper on this very subject on our (web) site. You'll see it there soon. To help our Mark Levinson customers understand more about what's going on inside their processors (already), we're about to release new software that will allow the customer to see the output sampling rate (versus the input rate, which is what they see in the display now) with the touch of a few buttons. Mind you, this is all the new software does; add a feature not a capability, as OUR DACs HAVE BEEN DOING THIS UP-SAMPLING (OVER-SAMPLING) FROM THE VERY BEGINNING. Stay tuned and thanks again for asking about the facts versus the hype." Todd Sutherland, Madrigal Audio. (emphasis mine re: capital letters). As to the differences in music quality/character among different CD players and DACs, I think the Theta Digital response summed it up best: "implementation techniques vary". Madrigal has a nice web site, and I recommend that anyone interested in this subject check out their position paper. I don't know exactly when it will be posted. This whole thread has been very informative-- well mostly. Thanks. Craig |
Hi Carl; I certainly hope you don't think (that I think) that your opinions are irrational on this subject-- we're all doing our best to understand it and its significance. You actually understand many of the details of this complex engineering subject, whereas I never will. I respect you, your views, and enjoy your posts. As to this subject; as a result of responses from Jeff Kalt (by Greysquirrel), Theta Digital, and Madrigal Audio, I've concluded that I was totally wrong about over-sampling vs upsampling-- these industry leaders apparently consider them the same thing, and I for one am glad to finally know this. My ego wasn't bruised at all when I found that my perceptions were wrong. As to differences in sound quality of digital components, I'll say again that Theta Digital is probably right when they say "implementation techniques vary". And that also explains why dCS gear may be so good (and so expensive) while others are building "up-sampling" components for a few hundred dollars. I'm looking forward to seeing Madrigal's position paper. Cheers. Craig. |
Hi Deborah1; Perhaps you're just humorously playing with words when you end your , but perhaps not. And It's not my intent to be demeaning in this observation: "chow" = food, but "Ciao" (also pronounced "chow") is an Italian? word usually used to express a pleasant Good bye. for goo |
Deb; I didn't even mean for the above Garfish 8/5 post to be posted. And it is of course only a partially composed message in any event. I thought I hit "reset" and thus erased it. Sorry. Craig |
Hi Kevin; Can you tell us where the article re: upsampling/oversampling you refer to will be posted or published? Thanks. Craig. |
Hi Jordan and Carl; Last night I read (twice) J. Scull's Stereophile review of Accupase's newest CD player. On the opening page, JS refers to the process Accuphase uses as oversampling, then throughout the rest of the review he refers to it as up-sampling. BTW, JS marginally preferred the Accuphase to dCS gear. Of course some question J. Sculls judgement. It was definitely confusing. And I know in previous posts on this subject, Carl has pointed this out-- that at least some of Stereophile's reviewers-- including J. Atkinson, have really extolled the virtues of high quality "up-sampling" devices. And that's why I also originally believed that up & over sampling were different. It was only after hearing from some of the leading industry people such as Jeff Kalt and Kevin Halverson that I changed my mind. In short, Stereophile led me and many others down a "screwy amd misleading path". I see no point in trying to contact Stereophile about this as I've tried emailing them in the past with no results. Cheers. Craig. |
Off the subject. Carl.... I've been curious for a long time why you seem to have such a preoccupation with people's Audiogon User Name(s), and for that matter their real names. Afterall, this is cyberspace and anyone can use whatever name they want (in good taste). For all we know, your real name could be Carla, I could be Geraldine, and Jordan could be Janie. But really, I think we're all genuine, ie what we appear to be. Chow. Craig. |
Carl; In my above post I was complimenting you for bringing it to Audiogon readers attention that JA and Sterophile have been talking about and promoting "upsampling" for quite awhile-- the rest of us kind of glossed over that important fact. The media (Stereophile) can do a lot more educating than anyone on Audiogon can, but they haven't done it in this case-- and I read and like Stereophile, and respect John Atkinson. I got particularly curious about your name interest thing when you almost singlehandedly ran Deborah1 off Audiogon; I have no interest in dwellining on this, but it seems important to you: I've been happily (mostly) married to the same woman for 35 years, and I'm totally secure in my sexuality. And I realize some of your "name play" thing is just in jest. Cheers. Craig. |
Joe; for a 25 year old you certainly have a mature and positive outlook on life. I read your long post carefully and it's excellent-- I share your views, and apologize for contributing to some of the negativity found here. The only quibble I chose to mention (and it's minor) is that I would not be "in awe" of meeting people such as J. Atkinson or audio industry leaders, but of course I would be pleased to meet them. But that's my perspective at age 57, and after completion of a 32 year career as a Senior Forest Soil Scientist (last 15-16 years) with the Dept. of Interior here in Oregon. I only mention my profession to let others know something about me. Men (especially) often define themselves by their professions, businesses or job(s) etc., and I would be interested in knowing about others in this regard. But it is seldom ever noted here on Audiogon; as a positive example, I respected David99 for telling us he was a nurse as that tells me a lot about him. Carl, what pray tell, does PI mean? As I want to know what kind of a blowhard I am (if you're referring to me)? And I'm glad to hear that you and Deborah1 and her husband have become email friends. I had occasion to exchange emails with her too-- nice lady. I hope she'll come back on Audiogon. Cheers (and I mean CHEERS). Craig. |
My thanks to Kevin Halverson at MUSE for posting his explanation of up and over sampling-- I just read and copied it-- it's great. And I agree with Treyhoss' post above-- it caps this confusing issue nicely. Thanks. Craig. |
