Audio Myth - "DSD Provides a direct stream from A/D to D/A."

[tailspn]

Possibly consider DSD as noise shaped 1-bit PCM.

 

No. By definition, PCM is digitized samples represented as absolute 2's complement binary word VALUES. There are no represented absolute VALUES in DSD (1-bit two level Pulse Density Modulation), only change of relative values represented through the density of bits in the bit stream.

[audiventory]

ADC too.

 

I'm not expert in ADC ( and DAC too , but as I know there are different principles of work PCM DAC.

 

There are many sigma-delta modulators too.

[audiventory]

No. By definition, PCM is digitized samples represented as absolute 2's complement binary word VALUES. There are no represented absolute VALUES in DSD (1-bit two level Pulse Density Modulation), only change of relative values represented through the density of bits in the bit stream.

 

 

One result from different sides (relative delta or noise shaped 2 level absolute values).

 

DSD DAC it is 1-bit PCM DAC.

[Hiro]

I'm not expert in ADC ( and DAC too , but as I know there are different principles of work PCM DAC.

 

Most of PCM ADCs are in fact SDM ADCs with internal PCM conversion step. In other words, the role of PCM in modern ADCs and DACs is that of a middleman.

[Hiro]

No. By definition, PCM is digitized samples represented as absolute 2's complement binary word VALUES. There are no represented absolute VALUES in DSD (1-bit two level Pulse Density Modulation), only change of relative values represented through the density of bits in the bit stream.

 

Correct.

 

And PWM is PDM's cousin...

PWM Definition from PC Magazine Encyclopedia

 

When you look at most audio devices you'll see that they are based on PDM/SDM/PWM rather than binary coded PCM.

[tailspn]

One result from different sides (relative delta or noise shaped 2 level absolute values).

 

DSD DAC it is 1-bit PCM DAC.

 

 

May be as characterized in a DAC implementation, or DSP process conversion, but I'm talking about a raw format.

 

PCM is a series of discrete 2's complement stand alone x-bit word values, each describing an independent analog amplitude level at the sample time. DSD is a analog bit stream who's relative amplitude values are encased in the density of the bits (which have no binary numerical weight as in PCM) in that stream. There's no numerical value represented, only relative bit density changes that must be further processed to yield digital process-able absolute numerical values.

 

They're completely different methods of representing varying signal levels, and I think it's confusing the issue to imply one is the 2nd cousin of the other

[audiventory]

I prefer anywhere (where possibly) found general base.

 

For DSD and PCM it is possibly.

 

Difference between PCM and DSD: audible part of PCM correlated with quantization noise (transmitted information increase -> the noise increased).

 

For DSD noise is not changed for any level transmitted information.

 

PCM use half spectrum for transmitting information.

 

DSD use small part of spectrum for transmitting information due necessity of noise shaping.

 

 

 

Here general base PCM and DSD decoding:

 

1. Part spectrum dedicated for transmitted signal.

 

2. Need suppress rest part spectrum.

 

 

 

General base for PCM and DSD coding:

 

1. Split to levels (two or more).

 

2. Apply/don't apply noise shaping.

[徐中銳]

For some years, I've been studying interviews of Marantz' Ken Ishiwata, even in foreign languages...

 

Excerpting the following insight, from his (September 2005) Se la passione determina la vita, specifically of why he prefers « bitstream » :

agisce solo su un bit alla volta, ma seguendo lo spettro musicale completamente in ogni momento. È un modo migliore di catturare la musica rispetto al PCM. Un’altra cosa interessante è che non c’è bisogno di un convertitore DA. Predisponendo il bitstream con un leggero filtro low pass, ottieni la musica originale. Il solo problema è misurare il jitter senza un convertitore DA. In questi casi, sulla base delle misurazioni, abbiamo solo le stesse specifiche di un compact disc ma quando lo ascolti è meraviglioso! Il problema è che commercialmente nessuno ha accettato questo…

 

Marantz è stata la prima a far uscire un lettore SACD…

Il problema è che abbiamo dovuto usare un convertitore DA, perché le persone, sulla base delle misure, si aspettavano una risoluzione a 20 bit e così il lettore doveva mostrare quella risoluzione alla misurazione!?!

 

Ma questo non potevo ottenerlo col solo filtro low pass, che mi dava solo 16 bit; mi dissero che non andava bene e nonostante io chiedessi di ascoltare quanto avevo fatto, nessuno accettò questa soluzione e io dovetti rinunciare all’idea di non usare un convertitore DA nel mio progetto, cosa che feci solo a casa per il mio divertimento personale. È possibile prendere il bitstream e farlo passare attraverso un ottimo filtro low pass e il risultato è un suono naturale, molto più godibile.

Google Translate :

It acts only on one bit at a time, but following the musical spectrum completely at any time. It's a better way to capture the music than the PCM. Another interesting thing is that you do not [have to] have a DA converter. Preparing the bitstream with a slight low-pass filter, get the original music. The only problem is to measure the jitter without a DA converter. In these cases, on the basis of measurements, we only have the same specs of a compact disc, but when you hear it is wonderful! The problem is that no one has commercially accepted this ...

 

Marantz was the first to bring out a SACD player ...

The problem is that we had to use a DA converter, because people, on the basis of the measures, expected a resolution of 20 bit and so the players had to show that the measurement resolution!?!

 

But that I could not get it with only low pass filter, which gave me only 16 bits; They were told that it was fine and although I asked you to listen to what I had done, no one accepted this solution and I had to give up the idea of not using a DA converter in my project, which I did only at home for my own amusement. You can take the bitstream and passed through a great low pass filter and the result is a natural sound, much more enjoyable.

Thus, how close is DSD to analogue itself ?

[tailspn]

Thus' date=' how close is DSD to analogue itself ?[/quote']

 

ding ding ding...We have a winner!

 

[Maldur]

Closer to analogue than PCM, definitely.

 

Due of needing high-frequency filtering, there is some slight variance, depending on implementation of this filter. This variance is mostly in higher audio band, and we can't directly hear this.

[The Computer Audiophile]

ding ding ding...We have a winner!

 

I don't think analog sounds good, so we have a loser :~)

[Hiro]

I don't think analog sounds good, so we have a loser :~)

 

Perhaps you're talking about your experience with vinyl? Which is a copy of analog tape. Here, we aren't talking about vinyl or tape, but representing the analog wave with pulse density modulation.

 

People often confuse analog with analog media such as tape or vinyl, whereas there are also analog pre-amps, analog amplifiers, etc and they are all ANALOG too.

[The Computer Audiophile]

Perhaps you're talking about your experience with vinyl? Which is a copy of analog tape. Here, we aren't talking about vinyl or tape, but representing the analog wave with pulse density modulation.

I'm talking about my experience with all analog sources. I grew up digital and that's what I'm used to :~)

[Allan F]

I'm talking about my experience with all analog sources. I grew up digital and that's what I'm used to :~)

I guess you prefer to be on the edge of music technology. Most digital definitely provided "edgy" for a long time, and more than a bit still does.

[Hiro]

I'm talking about my experience with all analog sources. I grew up digital and that's what I'm used to :~)

 

And yet you listen to stuff like NWA or Dr Dre which was all recorded to analog tape?

[bkinbk]

Pearl Jam too. At least the 1st bunch of records. Possibly still, but it's less clear these days.

[The Computer Audiophile]

I guess you prefer to be on the edge of music technology. Most digital definitely provided "edgy" for a long time, and more than a bit still does.

Ha!

[The Computer Audiophile]

And yet you listen to stuff like NWA or Dr Dre which was all recorded to analog tape?

 

Pearl Jam too. At least the 1st bunch of records. Possibly still, but it's less clear these days.

Definitely. I'd go nuts listening to the tape machine issues if I heard the albums played natively :~)

[tailspn]

I'm talking about my experience with all analog sources. I grew up digital and that's what I'm used to :~)

 

I grew up with microphone feeds. My experience is that it's downhill from a coloration perspective as soon as any recording process, digital, and especially any analog, is performed. Any recent (<10 years) implementation of digital recording, PCM or DSD adds less coloration than anything preceding. I just find that a first generation DSD take more realistic to the analog mic feed than any derived/processed result. That's not to say a boatload of PCM post processing can not make an outstanding and best selling recording. It's just not the mic feeds.

[The Computer Audiophile]

I grew up with microphone feeds. My experience is that it's downhill from a coloration perspective as soon as any recording process, digital, and especially any analog, is performed. Any recent (~10 years) implementation of digital recording, PCM or DSD adds less coloration than anything preceding. I just find that a first generation DSD take more realistic to the analog mic feed than any derived/processed result. That's not to say a boatload of PCM post processing can not make an outstanding and best selling recording. It's just not the mic feeds.

I'm jealous :~)

[sandyk]

I grew up with microphone feeds. My experience is that it's downhill from a coloration perspective as soon as any recording process, digital, and especially any analog, is performed. Any recent (<10 years) implementation of digital recording, PCM or DSD adds less coloration than anything preceding. I just find that a first generation DSD take more realistic to the analog mic feed than any derived/processed result. That's not to say a boatload of PCM post processing can not make an outstanding and best selling recording. It's just not the mic feeds.

 

Barry Diament reports the same about his 24/192 LPCM recordings and the microphone feeds.

[bkinbk]

Definitely. I'd go nuts listening to the tape machine issues if I heard the albums played natively :~)

 

You mean the master tape or from an analog source (ie vinyl)? I gotta tell ya, Vs., Vitalogy and No Code (originals) on vinyl all slay their CD or high res counterparts. The Yield CD is better than the vinyl though and Lightning Bolt sucks on LP.

 

Go figure

[tailspn]

I'm jealous :~)

 

No need. There's a growing catalog of DSD minimally processed (DSD edits only) available from a number of sources and labels. And allot more to come now that the Merging Horus/Hapi have made it so cheap to record acoustic music. The work that Gus Skinas has done for Chad recording the live Blues Festival albums, as well as Jared Sacks recent 8 Ensembles in 1-Bit comes to mind.

[tailspn]

Barry Diament reports the same about his 24/192 LPCM recordings and the microphone feeds.

 

Yes, it's very dependent on the venue, microphone types and placement employed, and type music being recorded. It's primarily reflected in spaciousness cues, which are very low level.

[davide256]

Definitely. I'd go nuts listening to the tape machine issues if I heard the albums played natively :~)

 

Curious... I refused to buy a CD player until 2001 because any player I listened to gave me the same unpleasant sensation during music play as a running dentist's drill. Since then digital has improved further but its still not effortlessly clean like analog. As to tape machine issues... yes if you are addicted to solid state amps, tape hiss can also feel like the aforementioned dentist drill. Tube amplification and MC cartridges will fix that for LP's