Analog Output In the digital realm - Need another lesson

[timetohunt]

Once and a while I get boggled with understanding the very basics of this hobby.

Here is one for which I could use a little response on.
Discs that we play contain pits and lands which represent digital audio data, correct ?

Its all digital for transmission through wire to wherever that audio data is going, correct?

1. What then is meant by Analog these days? For example, simply the 2 analog outs from a CD player or the 5.1 analog outs for high resolution.
What part of this scenario IS Analog ?

2. I know this may sound like a dumb question, but what then is a Signal as relates to this topic.

Thanks.
t

 

[MDS]

Simplistic answers first, because this type of question will open up a huge can of worms as explaining one thing often requires explaining what that is built upon and in turn what that is built upon, etc.

Discs that we play contain pits and lands which represent digital audio data, correct ?

Correct, but it's not just a linear sequence of data.

Its all digital for transmission through wire to wherever that audio data is going, correct?

Not really. A wire cannot transmit ones and zeros. A digital signal is analog, but instead of it being the actual waveform the digital data is 'modulated'. A simple example might be PWM (pulse width modulation). The 'pulse' is always the same, say 1 volt, but the width (amount of time it stays at one volt) determines if it is a one or a zero.

1. What then is meant by Analog these days? For example, simply the 2 analog outs from a CD player or the 5.1 analog outs for high resolution. What part of this scenario IS Analog ?

Analog is the actual waveform - what we hear. If you were to look at a 60 Hz sine wave you'd see that it oscillates around zero 60 times per second.

I know this may sound like a dumb question, but what then is a Signal as relates to this topic.

'Signal' is just a generic term that means the content sent between devices - whether that 'content' is the actual analog waveform or digital data.

 

[timetohunt]

Not really. A wire cannot transmit ones and zeros. A digital signal is analog, but instead of it being the actual waveform the digital data is 'modulated'. A simple example might be PWM (pulse width modulation). The 'pulse' is always the same, say 1 volt, but the width (amount of time it stays at one volt) determines if it is a one or a zero.
Thanks. Explain this scenario to help me understand it a bit better. Lets say you have a CD player (with DACs) connected via analog L/R outs and one s/pdif connection. What exactly is going through the wire or being output under each of those conditions.

Analog is the actual waveform - what we hear. If you were to look at a 60 Hz sine wave you'd see that it oscillates around zero 60 times per second.

'Signal' is just a generic term that means the content sent between devices - whether that 'content' is the actual analog waveform or digital data.
See, here is where I lose it again. What do you mean waveform or digital data, I thought a wire could not transmit ones and zeros..

Thanks.
t

 

[j_garcia]

I think in terms of what you are asking specifically - from one device to another, not internally, analog is already decoded and is passed via an analog connection (RCA 99.9% of the time). Digital could be via a variety of connection types (coax [which is RCA], optical, HDMI, etc...) which are generally an unprocessed digital signal being passed to be decoded by another piece of gear such as a receiver, and then on to amplification.

 

[MDS]

Explain this scenario to help me understand it a bit better. Lets say you have a CD player (with DACs) connected via analog L/R outs and one s/pdif connection. What exactly is going through the wire or being output under each of those conditions.

I told you this is going to get hairy, but I'm game. I'm not sure I can fully explain, but I'll try.

- If connected via analog outputs, the player is going to decode the digital data to analog. In the case of playing multi-channel DD/DTS but using 2 channel analog interconnects, it is going to downmix it to 2 channel analog. Now you have two channels of analog data. If you were using 5.1 analog outs, you have 5.1 separate analog channels - one for each channel, with no downmixing.

Analog is analogous to the real world. In other words, the signal is going to vary in voltage and amplitude according to the real waveform. If you were playing a 60 Hz sine wave, the signal will start at zero, rise to pi/2, cross zero again, then fall to 3pi/2, then rise to zero again, and repeat...60 times per second. Music of course is far more complex and is the sum of a potentially infinite number of sine waves and the voltage and amplitude will vary.

See, here is where I lose it again. What do you mean waveform or digital data, I thought a wire could not transmit ones and zeros..

This is super hard to explain. Ones and Zeros are a logical concept. A sequence of ones and zeros 'encode' (for lack of a better term) some content. Say I want to send the letter 'A' and the encoding is ascii. The ascii value of 'A' is 65 (decimal). The binary value (using 8 bits) is 01000001.

Now you can send that binary data using any number of modulation schees. S/PDIF uses bi-phase mark, which is too complicated to explain. Suffice it to say that the receving end recognizes the format and can distinguish a logical one from a logical zero.

Let's say that it was a simpler format like PWM and that .5 seconds is a zero and 1 second is a one. It would send 1 volt at .5 seconds in duration (0), followed by 1 volt at 1 second (1), followed by one volt at .5 second (0), etc. The receiving end knows it is dealing with 8 bits at a time and so will accumulate all that into 01000001 and recognize that as 65, aka 'A'.

If it were analog, it wouldn't be one volt at one second, it would vary according to the actual signal.

Does that make sense? It's kind of hard to explain.

 

[timetohunt]

Yea. I think so. Many years ago, I was an applications programmer and sometimes dealt with assembly language, moving bits and bites around. So at least I can stay in the ballpark with you on some of this.

So let me see if I got this right and boil it down to a couple sentences.
Tell me if this is accurate.

Analog audio data is the actual waveform of the sounds we hear. Y/N

Digital audio data is a modulated representation of ones and zeros which will be decoded to create the actual waveform of the sounds we hear. Y/N
............................
Also would these statement be accurate?

All audio discs (CD HDCD DVD-A SACD) contain digital data, nothing else.

Digita audio data is proportioned on the disc (at time of disc writing) based on whatever modulation scheme is intended.
................................................
Is 'modulation scheme' and 'digital audio format' the same thing?

Is PCM and DSD considerated a Modulation Scheme?

Then is Dolby Digital and DTS also considered a Modulation Scheme or something else?

Note: I do understand DD and DTS, how they are used and what they provide in terms of our HT systems, so no explanation is needed on that. I was basically wondering if 'modulation scheme' and 'audio format' are interchangable.

Thanks again.
t

 

[MDS]

Analog audio data is the actual waveform of the sounds we hear. Y/N

Yes

Digital audio data is a modulated representation of ones and zeros which will be decoded to create the actual waveform of the sounds we hear. Y/N

Yes

All audio discs (CD HDCD DVD-A SACD) contain digital data, nothing else.

Yes

Digita audio data is proportioned on the disc (at time of disc writing) based on whatever modulation scheme is intended.

Digital audio data is a bunch of numbers arranged in whatever structure is required by the storage medium. The format of the data is not necessarily related to how that data would be modulated to be sent over some communication channel.

For example, the same data sent over tcp/ip will be modulated differently if it is hard wired vs wireless. Coax digital vs optical digital use the same modulation scheme but the pulses that represent one vs zero are electrical in the coax case and light in the optical case.

 

[j_garcia]

CDs and DVDs are 100% digital. When the player reads it, it can either internally decode that data in an onboard DAC (Digital to Analog Converter) and it is then passed as an analog signal to another piece of gear for preamplification and/or post processing and then off to amplification. Most players can also pass the undecoded stream on directly to another piece of gear (receiver, outboard DAC, etc...) to do the decoding and then that analog data is sent to the amplification stage.

 

[AcuDefTechGuy]

All audio discs (CD HDCD DVD-A SACD) contain digital data, nothing else.

Is PCM and DSD considerated a Modulation Scheme?

Maybe I can learn something here too.

Yeah, all 3 of the above are DIGITAL. PCM, MLP, & DSD are all digital.

CD HDCD & CD are in PCM.

DVD-A is in MLP (Meridian Lossless Packing) INcoded digital format which are then DEcoded into PCM.

SACD is in DSD INcoded digital format which can either be DEcoded into Analog (Source Direct/No Bass management) or PCM (Bass Management).

PCM & DSD = Modulation Scheme.

ANALOG = The Final Stage --> Acutal sound we hear.

Example:
CD HDCD/CD --> 2Ch PCM (lossless) --> 2Ch Analog
DVD-A --> 5.1Ch MLP (lossless)--> 5.1Ch PCM --> 5.1Ch Analog
SACD --> 5.1Ch DSD (lossless) --> 5.1Ch Analog

DD/DTS --> 5.1Ch (lossy) INcoded --> 5.1Ch PCM --> 5.1Ch Analog

TrueHD/DTS-MA --> 7.1Ch (lossless) INcoded --> 7.1Ch PCM --> 7.1 Analog

So, EVERYTHING on any CD, DVD, BD is DIGITAL AUDIO.

If it's not already in PCM (like MLP, DD, DTS, TrueHD, DTS-MA) it will be DECODED and then converted to PCM. The ONLY EXCEPTION is SACD's DSD, which does NOT have to be converted to PCM. However, most SACD players, even Oppo's excellent $400 Universal player, will automatically convert EVERYTHING (including DSD) into PCM.

But this is the question: Is PCM or DSD better?

 

[gus6464]

At sa-cd.net I keep seeing a lot of SACD titles (mostly japanese releases) which are in DSD format. Does this mean the master is done in DSD and thus you need a DSD capable player to hear it in it's true form? So a player that is not DSD capable will just convert the DSD into PCM right? Is DSD superior to PCM?

 

[AcuDefTechGuy]

At sa-cd.net I keep seeing a lot of SACD titles (mostly japanese releases) which are in DSD format. Does this mean the master is done in DSD and thus you need a DSD capable player to hear it in it's true form? So a player that is not DSD capable will just convert the DSD into PCM right? Is DSD superior to PCM?

Well, you need a SACD player to even playback the DSD.

And even then, most SACD players will automatically just convert DSD to PCM.

Theoretically, I think DSD is superior than PCM. But practically, I don't know.

My understanding is this.

If we look at the final audio sound as a SINE wave, we see this smooth looking sine-wave. The curved line is smooth as it oscillates up and down. That's what DSD is supposed to look like -- the final analog sine wave.

PCM is a representation of a sine-wave with PERPENDICULAR STRAIGHT lines. Imagine drawing a sine-wave with only 90 degrees perpendicular lines, instead of smooth curved lines. This is PCM.

View attachment 6053

Of course, once PCM is converted to Analog, you also get the smooth sine-wave. But theoretically, PCM has more distortion than DSD. But then again, the distortion is most likely insignificant. This brings us back to the practical vs theoretical DSD vs PCM.

 

[gus6464]

Well, you need a SACD player to even playback the DSD.

And even then, most SACD players will automatically just convert DSD to PCM.

Theoretically, I think DSD is superior than PCM. But practically, I don't know.

My understanding is this.

If we look at the final audio sound as a SINE wave, we see this smooth looking sine-wave. The curved line is smooth as it oscillates up and down. That's what DSD is supposed to look like -- the final analog sine wave.

PCM is a representation of a sine-wave with PERPENDICULAR STRAIGHT lines. Imagine drawing a sine-wave with only 90 degrees perpendicular lines, instead of smooth curved lines. This is PCM.

View attachment 6053

So who makes DSD capable players other than Sony? Also I read that DSD has to be done through analog connections through the player and cannot be done with hdmi. Sony DSD capable players are very expensive to boot. This is one of those times I wished I lived in Japan.

Edit: I just that there are 2 ways to do DSD. You either need a player with a DAC that can handle DSD natively and not convert to PCM or a receiver with DSD capable DAC like the Onkyo 805. Now Sony now makes an SACD player which will send a DSD signal through optical but said DSD compatible receiver is still needed. This Sony SACD player costs $3000 So I guess it's all about the DAC being used and whether or not it can support native DSD.

 

[AcuDefTechGuy]

So who makes DSD capable players other than Sony? Also I read that DSD has to be done through analog connections through the player and cannot be done with hdmi. Sony DSD capable players are very expensive to boot. This is one of those times I wished I lived in Japan.

I know the Denon 2930, 3930, 5910, & Marantz 9500/9600 & above are DSD-Direct, but you have to turn Source Direct On, which bypasses all bass management.

The $400 Oppo player and I think the Harman Kardon players are NOT DSD-Direct.

My guess is that all the > $800 players are capable of DSD-Direct, and all the < $800 players are not.

DSD-Direct is possible with HDMI 1.2, Denon-Link III, and Analog.
It is not possible with HDMI 1.1 or Denon-Link II.

EDIT: Okay, so the $169 Oppo can send DSD-Direct via HDMI 1.2 only, not Analog.

 

[j_garcia]

The Oppo 980 can pass DSD direct and it is $169.

 

[AcuDefTechGuy]

You either need a player with a DAC that can handle DSD natively and not convert to PCM or a receiver with DSD capable DAC like the Onkyo 805.

But the player MUST be a SACD player. You can't just use any player to play DSD.

And the receiver must have DSD-Direct capability. To test this, you must not be able to do any bass management. If you are still able to do bass management, it means that the receiver is not DSD-Direct capable because the DSD has already been converted to PCM.

 

[AcuDefTechGuy]

The Oppo 980 can pass DSD direct and it is $169.

So the $400 flagship Oppo cannot pass DSD direct, but the $169 Oppo can?

What's wrong with this picture?

Interesting. The other 2 more expensive Oppo players cannot pass DSD-direct, but the 980 can via HDMI-1.2. It doesn't look like it can decode DSD directly to analog inside the player, but it can send the DSD-direct signal to a processor with DSD-direct capability. In other words, it is a DSD-direct Transport.

 

[gus6464]

But the player MUST be a SACD player. You can't just use any player to play DSD.

Yeah I know, I just figured that was understood lol

 

[timetohunt]

The Oppo 980 can pass DSD direct and it is $169.

It looks like we have some dissagreement here relative to wheather or not players (specifically the Oppo mentioned) will pass DSD direct. I will call Oppo to see what they say.

I am very interested in this, because the ability to pass DSD over HDMI intrigues me. Since I play SACDs, the idea of getting control over those signals with my receiver has me deeply interested. This is fairly new stuff, because HDMI 1.2 which I believe is the version that allows multi channel high resolution formats, has only been around since 2005. From a practical standpoint its only now making its way into disc players. Companies like Pioneer and Yamaha have not had this - Until now. Yamaha is just now selling its DVD-S2700, which I think may have it. Pioneer has not yet made any available, but I heard they would be within the next 2 months.

So folks, this really is kind of a new capability. There may be much to gain for those of us who play SACD and DVD-A.

 

[gus6464]

Oppo 980H
Direct Stream Digital (DSD) over HDMI (Requires compatible A/V receiver)

Well that sucks because if you don't have a receiver with HDMI and whose DACs can actually output DSD without converting to PCM you still screwed.

It's funny how you see a player and you are glad it can play sacd but there is still so much more to it. So in essence for a player to be a "true" SACD player it has to output DSD either by it's own DAC or you have to have a compatible receiver with a native DSD DAC.

 

[timetohunt]

So the $400 flagship Oppo cannot pass DSD direct, but the $169 Oppo can?

What's wrong with this picture?

Interesting. The other 2 more expensive Oppo players cannot pass DSD-direct, but the 980 can via HDMI-1.2. It doesn't look like it can decode DSD directly to analog inside the player, but it can send the DSD-direct signal to a processor with DSD-direct capability. In other words, it is a DSD-direct Transport.

I just spoke with my local audio shop guy and he did some research.
The Yamaha DVDC961 is capable of DSD direct through HDMI.
Like the Oppo situation, what really weird is that the new S2700 can not do it. Its about $800. The C961 can, is about $380, and also is a 5 disc changer - with some kind of disc isolation system like a single disc player. The store guy said its the only changer he knows of that does this.