A Simple Question about SACDs

Per my understanding, all SACD MCH is six channel at the physical and logical levels. The roughly 25 year old SACD Scarlet Book standard does not contain contingency for 3-5 channels, for example. All unused channels will be 0101… or similar code for DSD silence. And DST compression will handle the silent channel redundancy. At this point, it is what it is.

AJ

The original SACD’s from the turn of the century did not contain a CD layer. Those dics of which I still have several will not play on a CD player.

There were some single layer stereo-only SACD’s made early-on around the launch of SACD. The record companies then realised that to help ensure the format’s success, they had to produce Hybrid’s with a CD/RB layer.

Saying rhat, there are still some single layer, stereo-only discs being produced, primarily in Japan:

image

Personally, I love the format. I’m lucky to have collected around 1k of them over the years.

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DSDIFF spec lists these combinations of layers for an edited master (used to create physical discs):

A disc can consist of 1 or 2 areas. The following combinations of areas on a disc are
allowed:
· 2-channel area
· 5-channel area
· 6-channel area
· 2-channel and 5-channel area
· 2-channel and 6-channel area

In this particular case, the physical multichannel layer most probably contains 5 channels.

That is because BIS says they record/master in PCM. What I am saying is that there’s no agreement about whether such results would be better/worse than recording/mastering in DSD.

In general, I do prefer to buy in what is closest to the mastering, rather than the recording format.

Agreed…unless one already owns those old SACDs.

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Technobabble jargon inbound! Please strap yourself in!

To store an analog thing (wave) digitally it is sampled and converted to a defined bitstream which represented the waveform of the analog. A wave, lookup a picture of a sine wave, holds data like amplitude, phase, period, etc. In audio, the goal is to sample the audible frequency of the wave and then reproduce that wave somewhere else; covert the digital back to analog.

There are two predominate encoding methods for analog waves.
Linear Pulse Coded Modulation (LPCM, or just commonly PCM)
Pulse Density Modulation (PDM, or the method DSD uses at 1 bit)

LPCM uses an absolute set of values to represent the amplitude of the wave; the bit-depth.

DSD, being 1 bit, only represents two possible values of the wave; high (1) or low (0). It does this at such a high resolution these transitions from high to low in the analog reconstruct allow for analog wave when run through a D/A convertor (after high pass flier). That’s the “density” in PDM. The bits are packed at a very high density.

This difference is debatable as how audibly different DSD vs. PCM is at equivalent resolutions. However, to most people, they do sound different and therefore one is often preferred over another.
A few of us debated this and went into details here:

Yes, because capturing the DSD on the SACD is the only way to preserve the PDM encoded audio. FLAC is a container for PCM. You need to store the DSD into something that preserves the DSD (like a DSF).

The other “problem”, as others have pointed out, is that some SACD’s (called hybrid-SACD) is a multilayer technology allowing for both a traditional CD (or “redbook”) layer as well as the SACD layer (containing the DSD). If you rip the CD layer you’re not capturing the SACD part (DSD) you’re only capturing the CD at 16/44.1 PCM. DSD also supports multiple channels so a multichannel SACD may have both a 2 channel and multichannel version of the album. You’d need to rip both of these if you want to capture them.

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Keep in mind that if you need to do any post-processing of recorded material before producing the master, you need to convert to PCM (or multi-bit samples, if you prefer), since DSD is not suited for DSP. That’s why it makes sense to record in PCM, post-process as much as you want, then perform a one-time conversion to 1-bit to produce the DSD master.

I’ll add… You cannot master in 1 bit. It’s impossible. So cannot master in DSD. You can master in PDM but only at > 1-bit which means it’s not DSD.

This is why most all DSD recorded music, if it’s not directly released, is mastered in PCM then converted back to DSD. Digital mastering requires maths and you can’t maths with a single bit. :slight_smile:

Only if he already owns an OPPO, Pioneer or PS3 which is capable of extracting the DSD layer. But if he doesn’t, why spend the money on such a machine to get and approximation to something you could download perfectly from eclassical, or indeed stream from Qobuz.

Well, you can do algebra on the additive and/or multiplicative modulo-2 group {0,1}, but that’s not what you want :slight_smile:

In theory you can if you don’t do any post-processing. I heard some studios publish unedited live performances - mostly jazz and chamber/classical, I would assume. I personally don’t see the benefits of this puristic and very limited approach, just as I don’t see the benefits of DSD (and I won’t elaborate on this, since I did it extensively on other threads).

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Agreed but that depends on what and how much editing you need to do. Well balanced 5-microphone recordings in DSD may need little but edits.

Yes and some of them are outstanding although I am loath to ascribe that to any particular factor.

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Any editing other than trimming - even applying gain - needs more than 1 bit.

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Is splicing tape considered mastering? :slight_smile:

I have an OPPO 203 and a Sony Blu-Ray player.

Yes, eClassical offers the entire BIS catalogue, including surround mixes when they exist – https://www.eclassical.com/labels/bis/.

It’s a great source of multichannel music.

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The Oppo 203 is not capable of ripping SACDs; only the 103(D) and 105(D) models.
Some Sony BD players will do it. Depends on the model.

And some of those Sony players can still be found for under $50 on eBay.

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I think I found one. (I say “think” because the last of these ebay deals arrived DOA.)

I shall report any progress. Thx

“A Simple Question about SACDs”
Hmm…

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