Javier
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Post by Javier on Apr 11, 2013 21:45:04 GMT
Provisional "conceptual" graph of DSD proyect:
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Dave
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Post by Dave on Apr 18, 2013 8:33:19 GMT
Hi Javier and anyone else who might be interested, I'm well aware that we've discussed this before (my memory is not that bad ) and I'm not wanting to start any argument with you or anyone else but I wonder if anyone else could confirm what I think I had. Some years ago my local Sony Centre (Meadowhall) was selling off some HT PCs at 'giveaway' prices and I 'invested' in a VGX-XL201. One of the programs pre-loaded was SonicStage Mastering Studio and this offered the facility of recording music in DSD format. I used it once that I can recall to digiitise an LP which I then sent to a member of another forum. He responded with the comment that it was much better SQ than he expected. Sadly, since that PC expired I have been unable to find the actual files. I stress that this was well before I had anything more than a passing, novice interest in audio SQ so I was not really aware of what I'd done. Since that time I have bought off ebay an original Sony CD purporting to be SonicStage Mastering Studio but there is no mention of recording in DSD format anywhere on it. Can any members or, more likely, visitors, throw any light on this situation? I am not disputing the logical arguments against Sony making this technology available to the wider world but, equally, I cannot ignore what I remember seeing and doing so let's keep the responses friendly, eh? TIA, Dave.
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Post by CJ on Apr 18, 2013 12:05:33 GMT
Hi Dave, I used the Sony programme a lot back in the Mini Disc days and always liked it. No idea for DSD though, that's a very new thing to me. Maybe this will help; www.sony-asia.com/support/faq/50869CFN
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Javier
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Post by Javier on Apr 18, 2013 14:45:26 GMT
Most Sony's DSD software was very tightly bound to specific computers with specific configurations (hadware and software). If you want to use it you'll probably need to bring that VAIO back to its original state. Whether or not the use of that particular is worth the hassle and draw backs is you choice.
Before making any decission, I'd say it'll be interesting to know some facts. First thing would be learning what ADC chip did your VAIO use. If like I suspect was a Sony rebranded Realtek CODEC IC then the computer was never really able to record in "true" DSD format as no Realtek CODEC chip I know of outputs DSD, only I2S (aka PCM). The Studio application most probably did a PCM to DSD on the fly conversion in order to store the analogue capture as DSD. There are not many ADCs capable of outputting true DSD like the PCM4202 and they are not found in laptop PCs. Some true DSD recording devices are available in the market but they don't come cheap and then if you need to do any further processing satying within the DSD domain things can get quite complicated for those without a recording studio.
For PCM to DSD permanent convertion purposes there are newer, more efficient and free solutions like Korg's Audiogate but still, when it can be done with good quality for free and real time using Foobar's SACD plugin I can't think of any reason for such conversions. It'll be like storing a 16/44.1 file upsampled to 24/192, just a waste of disk space as it can be prefectly done on the fly with fantastic accuracy.
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Dave
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Post by Dave on Apr 18, 2013 18:30:44 GMT
Hi y'all, especially Chris (cj), Thanks for your input - much appreciated , as are all your posts, so why not jump in with both feet and join us, none of us bite! . My problem, well one of 'em , is that I came to audio too late and the old brain is now incapable of picking up the differences between DSD and PCM and FLAC (and candy floss for that matter ), so most of what you and Javier posted went right over my head, sadly. This is not a plea for either of you to write an idot's guide to audio files, too late for that now. Providing the rest of the membership will continue to tolerate my numptie questions, total lack of knowledge and provide basic answers, I'll be happy. My naive and simple mind says that if a Sony audio progam presents me with an option to record in DSD mode then that is what it does. I undestand the reasons why such technology would not be put into the public domain but sometimes things happen that shouldn't happen, so I live in hope . Thanks again. Dave.
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Javier
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Post by Javier on Apr 19, 2013 10:03:55 GMT
My naive and simple mind says that if a Sony audio progam presents me with an option to record in DSD mode then that is what it does. I undestand the reasons why such technology would not be put into the public domain but sometimes things happen that shouldn't happen, so I live in hope . Thanks again. Dave. The difference between PCM and DSD requires a lengthy explanation and Wikipedia does a good job at it. A (over?) simplified, hopefuly easier to understand, version one could be that the former stores the signal using a long string of 0s and 1s and the latter uses just one digit, be it a 1 or a 0. PCM, due to these longer strings or "words" needs to capture a lower number of samples per second than DSD to describe the analogue wave form, this is called "sampling rate", for example regular CD uses 44,100 samples per second each one using a string of 16 0s and 1s to describe the analogue wave, a PCM word would be something like 1001101001010011 and that is just for one channel, in stereo two of those are used. That is more than 1.4 million 0s and 1s per second. Contrary to PCM, DSD needs a huge amount of samples per second to compensate for the single digit word, in the lowest case that would be 2,822,400 samples per second and channel, that is 64 times as many as PCM but total number of 0s and 1s in the stream is not that much higher, it'll be just 5.6M Vs 1.4M or 4 times higher. DSD produces a digital signal that resembles very much the original analogue one, to the extent that it can be directly converted and only needs a low pass filter to eliminate ultrasonic garbage produced by the decoding process. FLAC, WAV, MP3, AIFF, ALAC, APE, etc. are just containers. They all belong to the PCM family, some are losslessly compressed, others have lossy compression and others are uncompressed. DSD files have DFF, DSF or WSD extension. What I was trying to say is that the VAIO computer you have, no matter what Sony says, does not record or play "real" DSD at any time. With it you'll be recording regular PCM which is then converted to DSD and stored in that format. Also, when playing that very same DSD content, it will be converted back to PCM so the onboard sound card can "understand" it. It is more of a marketing gimmick that anything with real value. As ATM you have no means of listening to "true" DSD, IMO restoring your laptop to its original state is quite pointless as an experiment and adds no value whatsoever. I'd change my opinion if it could be proved with 100% certainty that the onboard sound does in fact record and play native DSD without any intermediate conversion to or from PCM. I'm sorry but I can't explain all the above in simpler terms, this is the best I can do.
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Dave
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Post by Dave on Apr 19, 2013 10:38:34 GMT
Hi Javier, Thanks for that - absolutely no need to apologise - and I am a little wiser now and will take a look at Wikipaedia with a slightly better understanding. BTW, not complaining, but you made no reference to 'candy floss' ;D ;D ;D . Dave.
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solderdude
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Post by solderdude on Apr 19, 2013 10:53:21 GMT
The basics are correct. I would add that in case of DSD at each given moment the momentary value of the analog equivalent is the average level of around 64 'samples' that have passed in about 22 microseconds. For those that cannot hear above 16kHz any more it is the average of 80 samples in about 28 microseconds. This is continously changing every every 0.3 microseconds though. For PCM it appears as though there would only be a change in sample value about every 22 micro seconds (for CD) BUT also here the average value between 2 samples 'glides on' over the same time period but in this case caused by the analog filter. The wiki: en.wikipedia.org/wiki/Direct_Stream_Digital is very inforamtive but the picture of the 'difference' between PCM and DSD is a bit misleading to say the least. It does show the differences in the way the signals are converted where the sine wave is the original signal and will be not nearly the same as the signal that can be retrieved from the pictured drawings. The PCM signal = 2.7kHz and about 3 bits 'deep' (so basically a test tone of 2.7kHz @ -76dB) The DSD signal = 80kHz sinewave @ close to 0dB. It is likely the DSD signal is derived from PCM and converted back to PCM. I could not find specifications of the audio chip used in the mentioned device. Sony was into 1 bit audio already tens of years ago when Technics had MASH (4 bit and oversampling) converters. It is not unthinkable, as the Sony device was dedicated to be a media device, that it could actually record and playback in native DSD as it seemed to be THE selling point. Cannot verify it though, and suspect it would only have been the lowest 2.8MHz 'version'.
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Dave
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Post by Dave on Apr 19, 2013 11:28:19 GMT
Thank you Frans . It is nice to hear that someone shares my view that "It is not unthinkable, .......... that it could actually record and playback in native DSD". That is not to say that I am right and anyone else is wrong, I am just happy that someone else thinks it is not unthinkable. I have a list of jobs to do that will not get finished if I live to be 100 but I do have the components to return the Vaio to it's original condition (hopefully ) but whether it will ever get done is debatable. If I do manage it I offer a TeamViewer session to anyone who is capable of determining what is actually happening. Thanks again, Dave.
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Javier
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Post by Javier on Apr 19, 2013 13:20:25 GMT
I think long time afo I read somewhere that the onboard CODEC used by that VAIO line was just a Sony rebranded Realtek chip with an "exotic" name though the info could be wrong. That is the reason I mentioned that IF that wasn't true and it indeed have a DSD compatible chip then native DSD could actually be possible. The problem is that Sony hasn't ever made any soundcard chips AFAIK. The answer will be known if you are able to find exactly what chip/s the VAIO uses.
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Javier
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Post by Javier on Apr 19, 2013 13:33:11 GMT
If I do manage it I offer a TeamViewer session to anyone who is capable of determining what is actually happening. Thanks again, Dave. Not really needed, you can check yourself what sound card drivers you are using now in the control panel under system properties->device amanager -> sound.
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Javier
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Post by Javier on Apr 19, 2013 14:12:01 GMT
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solderdude
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Post by solderdude on Apr 19, 2013 14:20:22 GMT
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Javier
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Post by Javier on Apr 19, 2013 14:35:35 GMT
Looks like it was a SigmaTel part. The company sold all its audio business to IDT mid 2006 and the rest to Freescale which is now a "ghost" company. I can't find any data sheet for that part at the IDT site nor anywhere else.
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Javier
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Post by Javier on Apr 19, 2013 14:50:40 GMT
There are no W7 drivers for the SigmaTel chip but with some luck Vista ones (which are available) can be used. Same goes for Mastering Studio app. Dave, I can try to help if you need assistance.
One sure thing is that even if native DSD is possible, there will be no easy way to get a DSD digital stream out of the PC, knowing Sony it'll only be available on the analogue outputs and the SQ of these onboard CODECS is not the quite the best.
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