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ncdrawl
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Answer me this.

If a player offers "sacd/dsd" playback, but in the process of doing so, downsamples the data (as with the Oppo 970)...

how is that DSD Playback??? Anyway, it sorta pisses me off. I wonder what good something like that is? Isnt it false advertising?

because it isnt really SACD playback at all really..

Drtrey3
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Re: Answer me this.

I'd be pissed off too. It means you need a second disc player to play the resoloution you payed for when you bought the sacds. To me, sacd/dsd playback conveys full resoloution dsd. It more than implies it in my reading.

Trey

struts
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Re: Answer me this.

I'm not sure if I agree nc. Consider the following statement from the Linn Records website: (my bold)

Quote:
Studio Master FLAC

If absolute sound quality is what you want then this file is best for you.

FLAC files are lossless at various high bit rates, for example, 44.1kHz, 48kHz, 88.2kHz, 96kHz and 192kHz (check each title for actual details). The quality is identical to that of an SACD (Stereo only). The format will be dependent on the actual recording method we used originally. No DSD files are offered as it is not possible to play them back on a PC so an equivalent PCM format is offered. These files offer true "studio quality" and are what was used by Linn to produce the production version of our CD releases. Be sure to check compatibility with your computer sound card etc before you download a file and note that large amounts of storage space are required for each track.


I am assuming Linn used the terms "identical" and "equivalent" advisedly, in which case they seem to be saying that it is the resolution of the recording that is important and not the delivery mechanism. A recording mastered at 24/96 contains a signal with no more than 146.24 dB of dynamic range and no more than 48 kHz of bandwidth regardless of whatever medium it is subsequently transferred to. All digital formats capable of storing this amount of information without loss/distortion are therefore effectively equivalent.

The raw data rate of DSD is 5.6 Mbps whereas that of 24/96 LPCM is 4.6 Mbps, so one might suspect that DSD is capable of holding more musical information. However my understanding is that the DSD's effective dynamic range is 120 dB (== 19.64 LPCM bits) while its effective bandwith is limited to 50 kHz by the low pass filtering needed to remove the quantization noise from the noise shaping. Hence the usable resolution of DSD is roughly equivalent, maybe even slightly inferior to 24/96 LPCM and almost certainly inferior to that of 24/176.4 LPCM. Interesting then that in tests conducted at the Erich-Thienhaus Institute and subsequently reported at the AES subjects were unable to tell the difference!

I have to confess I don't know enough about DSD to know how 'lossless' the process of converting it to an "equivalent" PCM file would be. However if a lossless coversion is indeed possible, does it matter whether this is done in Linn's mastering suite or in the firmware of your player? Is there in fact a complete DSD/SACD production workflow that doesn't involve any conversion back-and-forth to PCM??

Can any DSD gurus shed any light on this?

Kal Rubinson
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Re: Answer me this.


Quote:
If a player offers "sacd/dsd" playback, but in the process of doing so, downsamples the data (as with the Oppo 970)...

how is that DSD Playback??? Anyway, it sorta pisses me off. I wonder what good something like that is? Isnt it false advertising?

because it isnt really SACD playback at all really..

Sure it is but it is also misleading in that you, and others, would reasonably expect full bandwidth data. Fortunately, the early Oppo 970 is not representative of most modern SACD/CD players.

(BTW, I do not know how the limitation applies to the analog outs of this player as it does to the s/pdif output.)

Kal

Elk
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Re: Answer me this.


Quote:
If a player offers "sacd/dsd" playback, but in the process of doing so, downsamples the data (as with the Oppo 970)...how is that DSD Playback???


I agree; it's not if it is down converting.

I guess you have something as it will "play" a SACD. <shrug>

As Struts points out (and I am sure you know) DSD can be transcoded to PCM (and is during production anyway). I wouldn't object if suitable transcoding was taking place - but down converting is unacceptable.

ncdrawl
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Re: Answer me this.


Quote:
Is there in fact a complete DSD/SACD production workflow that doesn't involve any conversion back-and-forth to PCM??

Can any DSD gurus shed any light on this?

Yes..

There are 3 DAWs that handle raw dsd files. Sadie, Pyramix, and the Sonoma system. The rundown..

All start with a 1-bit DSD source. All can deliver a final 1-bit DSD "master." How they get there is a different story, though.

The Pyramix, the instant you put the system in edit/mix mode, converts the DSD source to 24bit,325.8kHz pcm for all editing and then re-converts back to DSD for the output to DACs or mastering. All DSD audio, from beginning to end of what you're working on, has gone through the conversion/re-conversion process. This is NOT just simple math being performed. The audio goes through internal pcm and sigma/delta converters for the process.

SADiE (or Sonoma) keeps the DSD source as DSD (no conversion) except at the actual edit crossfade, where an insert occurs the length of the crossfade of 8bit,2.8Mhz pcm and back to DSD. This conversion occurs ONLY at the crossfade. All DSD source on either side of the edit is untouched as long as the "bypass mixer" button is pushed There is no low-pass filtering used or needed. The "annex" DSD metering verifies there is no increase in UHF noise.

anyway...my issue isnt "quality" as I have no horse in the race.. It just pisses me off that manufacturers get away with putting the "SACD" sticker on their players..when some of them output downsampled audio...so it isnt "really" dsd/sacd at all. I find this strange and very, very misleading. The folks that buy SACDs arent buying the format because they cannot get the music in any other form! They are buying SACDs for the quality, so these faked players are a scam.

I own the Sony 5400 SACD player now, the hotrodded OPPO is relegated to redbook, but..this topic has been bugging me for a long time. same thing with DVD Audio. Why??

If they dont output "real" dvd-a or sacd audio, they do not need to list it in the advertising or have the logos on the casework...

Elk
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Re: Answer me this.


Quote:
It just pisses me off that manufacturers get away with putting the "SACD" sticker on their players..when some of them output downsampled audio...so it isnt "really" dsd/sacd at all.

Agreed if it is downsampled.

How about if the DSD is transcoded properly to high bit rate/bit-depth PCM before it goes to the DAC chip? DSD is 1-bit, high sample rate PCM anyway.

I have mixed feelings. I want DSD to be taken of the shiny disc native and processed as DSD. But does it really matter?

ncdrawl
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Re: Answer me this.

I think it matters in that it is false advertising. I buy SACDs for the sonic benefit, and the sonic benefit only..so I want to hear it in the native form...not transcoded/upsampled/downsampled, etc..because, in my mind..anything other than the dsd spec--has no right using the "SACD" sticker

I know, I know..a lot of things to worry about, this may seem minute..but it seems to me like a big long con..

Elk
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Re: Answer me this.

I agree. If it says SACD it should convert native DSD.

In the alternative, we should be told its transcoded before converted by a PCM DAC.

Similarly, an SACD should have real life DSD on it. I find appalling that some SACDs are just transcoded Redbook digital.

ncdrawl
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Re: Answer me this.

I agree, Elk... I think DSD has place in one application, transferring from analogue. anything else is useless and self-defeating...so I am not interested in any SACD that was recorded in DSD by a digital recorder..just transfers from analogue.

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