DSD Battle Royale!

[garylkoh]

Gary,
Do you know of any equipment that can trans-code PCM to DSD in real time during playback, without writing or saving the DSD to files?

I recall JRiver talking about real-time PCM to DSD conversion, but I don't know if they have implemented it.

 

[mep]

No, but we can not discard the possibility that the Mytek PCM implementation is much inferior to the DSD one, and your strong opinions are partially due to it.

Maybe, but I have never liked PCM regardless of what CD player or outboard DAC was reproducing it.

Some people reported that they have found it to have a "dry" balance in it, perhaps DSD favors it. Just thinking loud, extreme opinions sometimes have hidden causes!

There is no "dry balance" to the Mytek when decoding DSD. I usually wear a rain coat when I listen to DSD through the Mytek. Seriously, DSD just sounds "right" in a way that I don't hear with PCM regardless of CD player or DAC. I quit buying hi-rez PCM files because I came to the conclusion it was just a waste of money.

 

[audio.bill]

I recall JRiver talking about real-time PCM to DSD conversion, but I don't know if they have implemented it.

It is my understanding that JRiver Media Center 19 offers this capability, either in real time or offline. The real time conversion utilizes a significant amount of PC resources so the hardware must be up to the task. Offline conversion does not have the real time data requirements, so it can be performed on less powerful PCs but does require storing the converted DSD files. Many users have reported very positive results with these conversions, particularly when used with DACs that are optimized to perform their best with DSD files.

 

[Orb]

dCS Vivaldi Upsampler definitely can convert on the fly from PCM to DSD, and for interesting comparison can also upsample PCM to DXD rates.
I thought it could do it other way round as well (DSD to PCM-DXD) but that looks like it may not be possible.

Cheers
Orb

 

[tailspn]

The onboard processing power available to DAC's is very limited compared to that of a modern multi-core CPU. Therefore they rarely, if ever implement more than a second order Delta-Sigma modulator for the real-time PCM to DSD conversion. Contrast that to the Signalyst HQPlayer which uses up to seventh order modulators to do the real-time conversion.

 

[audio.bill]

Gary,
Do you know of any equipment that can trans-code PCM to DSD in real time during playback, without writing or saving the DSD to files?

While I'm not aware of any such standalone conversion hardware, some DSD DACs convert all PCM digital inputs into a DSD stream which is then converted to analog. Some examples of DACs using this approach are produced by Playback Designs, Meitner, and EMM Labs.

 

[microstrip]

It is my understanding that JRiver Media Center 19 offers this capability, either in real time or offline. The real time conversion utilizes a significant amount of PC resources so the hardware must be up to the task. Offline conversion does not have the real time data requirements, so it can be performed on less powerful PCs but does require storing the converted DSD files. Many users have reported very positive results with these conversions, particularly when used with DACs that are optimized to perform their best with DSD files.

Interesting. We have to persuade Mark to use it to change his PCM files on the fly to DSD using JR MC19 and listen to them in this mode. I am a JRiver licensed user, as soon as I have some free time I will upgrade my version.

 

[microstrip]

While I'm not aware of any such standalone conversion hardware, some DSD DACs convert all PCM digital inputs into a DSD stream which is then converted to analog. Some examples of DACs using this approach are produced by Playback Designs, Meitner, and EMM Labs.

It is why I think that listening tests of PCM carried by users of such DACs are not meaningful.

 

[ted_b]

Tom is, I believe, an industry insider. He may even be a recording engineer (or a hardware designer).

I cant recall exactly, but I recall this from ComputerAudiophile.

Tom is being very modest, but is this past year's double Grammy-winning recording engineer for Classical recordings (he and John, Soundmirror). He knows a little.

Regarding transcoding on the fly (or offline). Yes, JRiver MC 19 can do either, and can do it either way (PCM to DSD and DSD128, or DSD to PCM). I am not a fan of on-the-fly except for i5 and i7 dedicated machines (and even then the cpu resources are theoretically noisy), so whenever I do it I'll bite the bullet and do it offline (Seagate/Western Digital love folks like us).

I notice Berkeley's new $14k Reference DAC announcement eschews the idea that DSD processing can be done native, and that one-bit DACS are BS, so why not just leave it to an external conversion (DSD to 24/176k), and so they throw in JRiver for that. Seems like quite a statement.

"Careful consideration was given to providing the highest possible reproduction of DSD files by the Alpha DAC Reference Series. 99% of modern DAC’s, including the Alpha Reference Series use multi-bit D/A converters because they provide better performance than 1-bit converters – even those who advertise “native” DSD compatibility. So, at some point, the 1-bit DSD stream must be converted to multi-bit for all of those DAC’s.

We could, like many other manufacturers, convert 1-bit DSD to multi-bit within the Alpha DAC Reference Series and show “DSD” in the front panel display. That would be the easiest approach from a marketing perspective. But that would also mean increasing the amount of processing in the DAC during playback which would degrade audio quality, and audio quality is the reason the Alpha Reference Series exists.

Fortunately, virtually all reproduction of DSD files using external DAC’s occurs with a computer based music server as the source. If the 1-bit DSD to multi-bit conversion is done first in the computer it can be performed with extremely high precision and superior filtering that preserves all of the content of the DSD file. Computer DSD to multi-bit conversion can be at least as good as that performed in a DAC and without adding processing noise near or in the D/A converter chip. Another advantage of computer based DSD to PCM conversion is that if higher performance DSD versions such as DSD 4x appear in the future they can easily be supported with a software upgrade.

For all of those reasons, DSD capability for the Alpha DAC Reference Series is provided by an included state of the art software application that provides either real time conversion of DSD 1x and DSD 2x to 176.4 kHz 24 bit PCM during playback or conversion to 176.4 kHz 24 bit AIFF or WAV files. The software application is included in the price of the Alpha DAC Reference Series and is compatible with either Windows OS or Mac OS based music servers."

 

[audio.bill]

Fortunately, virtually all reproduction of DSD files using external DAC’s occurs with a computer based music server as the source. If the 1-bit DSD to multi-bit conversion is done first in the computer it can be performed with extremely high precision and superior filtering that preserves all of the content of the DSD file. Computer DSD to multi-bit conversion can be at least as good as that performed in a DAC and without adding processing noise near or in the D/A converter chip. Another advantage of computer based DSD to PCM conversion is that if higher performance DSD versions such as DSD 4x appear in the future they can easily be supported with a software upgrade.

For all of those reasons, DSD capability for the Alpha DAC Reference Series is provided by an included state of the art software application that provides either real time conversion of DSD 1x and DSD 2x to 176.4 kHz 24 bit PCM during playback or conversion to 176.4 kHz 24 bit AIFF or WAV files. The software application is included in the price of the Alpha DAC Reference Series and is compatible with either Windows OS or Mac OS based music servers."

Bel Canto Design has taken a similar stance with their support of converting DSD files to 24bit/176.4kHz PCM for playback with their DACs. Details and their technical analysis can be seen on their website here.

 

[PhilipAC]

I find it very strange that, just as the number of DSD downloads becoming available is about to increase markedly, two big DAC companies are saying they are going to convert DSD to PCM before the conversion process. If you do this, what is the point of having the file in DSD in the first place?

Are we seeing an increasing separation of the PCM and DSD "camps"?

 

[microstrip]

Tom is being very modest, but is this past year's double Grammy-winning recording engineer for Classical recordings (he and John, Soundmirror). He knows a little.

Regarding transcoding on the fly (or offline). Yes, JRiver MC 19 can do either, and can do it either way (PCM to DSD and DSD128, or DSD to PCM). I am not a fan of on-the-fly except for i5 and i7 dedicated machines (and even then the cpu resources are theoretically noisy), so whenever I do it I'll bite the bullet and do it offline (Seagate/Western Digital love folks like us).

I notice Berkeley's new $14k Reference DAC announcement eschews the idea that DSD processing can be done native, and that one-bit DACS are BS, so why not just leave it to an external conversion (DSD to 24/176k), and so they throw in JRiver for that. Seems like quite a statement.

"Careful consideration was given to providing the highest possible reproduction of DSD files by the Alpha DAC Reference Series. 99% of modern DAC’s, including the Alpha Reference Series use multi-bit D/A converters because they provide better performance than 1-bit converters – even those who advertise “native” DSD compatibility. So, at some point, the 1-bit DSD stream must be converted to multi-bit for all of those DAC’s.

We could, like many other manufacturers, convert 1-bit DSD to multi-bit within the Alpha DAC Reference Series and show “DSD” in the front panel display. That would be the easiest approach from a marketing perspective. But that would also mean increasing the amount of processing in the DAC during playback which would degrade audio quality, and audio quality is the reason the Alpha Reference Series exists.

Fortunately, virtually all reproduction of DSD files using external DAC’s occurs with a computer based music server as the source. If the 1-bit DSD to multi-bit conversion is done first in the computer it can be performed with extremely high precision and superior filtering that preserves all of the content of the DSD file. Computer DSD to multi-bit conversion can be at least as good as that performed in a DAC and without adding processing noise near or in the D/A converter chip. Another advantage of computer based DSD to PCM conversion is that if higher performance DSD versions such as DSD 4x appear in the future they can easily be supported with a software upgrade.

For all of those reasons, DSD capability for the Alpha DAC Reference Series is provided by an included state of the art software application that provides either real time conversion of DSD 1x and DSD 2x to 176.4 kHz 24 bit PCM during playback or conversion to 176.4 kHz 24 bit AIFF or WAV files. The software application is included in the price of the Alpha DAC Reference Series and is compatible with either Windows OS or Mac OS based music servers."

Well, it seems they only claim that they are not worst than their competitors who converte DSD to PCM internally. But the critical question is how does it compare with native DSD converters. As far as I remember Bruce commented sometime ago that DXD384 was needed to preserve the DSD sound characteristics with minimal damage.

 

[wisnon]

On alternative is to do no convesrion at all and just filter the darn DSD in analog domain. You then get to the pure analog signal as it was meant to mee.

MMMhhh, LECKER!

 

[tailspn]

On alternative is to do no convesrion at all and just filter the darn DSD in analog domain. You then get to the pure analog signal as it was meant to mee.

MMMhhh, LECKER!

Actually, you're allot closer to being right on than you may think. DSD (1-bit two level Pulse Density Modulation) isn't digital in the first place, it's ANALOG! PCM is digital, in that it's a sequence of discrete 2's complement binary words of n bits, with each word being a stand alone digital expression of an analog signal level, at the sample time. It's just like frames of movie film, strung together to convey motion.

DSD, a Sony/Philips marketing term for a 1-bit two levels analog format is as analog as AM or FM radio. Like them, it's simply a signal modulating a carrier for transmission purposes, and detected at the receiving end to retrieve the signal. Unlike them, instead of modulating the amplitude or base frequency of a carrier, it modulates the density of pulses. This occurs as the product of a hunting/feedback process in a Delta-Sigma Modulator, creating a pulse stream clocked at the sample rate who's density is proportional to the signal level. No frames, no words, all continuous, and most distinguishing, no weight or value! That's why it has to be either converted to PCM to be processed in a computer, or converted to multi-bit Pulse Density Modulation, ala the Sonoma DAW.

Since it by definition has only two levels, a computer can store and retrieve it, just not process it, because it does not represent actual sample values. All it represents is change of levels through the density of the pulses in a continuous pulse stream. The higher the level, the denser the pulse chain. ANALOG!

That's why you're correct saying just filter it, and get the signal back.

 

[Bruce B]

Just put up the DSD256fs file!

 

[Andre Marc]

Actually, you're allot closer to being right on than you may think. DSD (1-bit two level Pulse Density Modulation) isn't digital in the first place, it's ANALOG! PCM is digital, in that it's a sequence of discrete 2's complement binary words of n bits, with each word being a stand alone digital expression of an analog signal level, at the sample time. It's just like frames of movie film, strung together to convey motion.

DSD, a Sony/Philips marketing term for a 1-bit two levels analog format is as analog as AM or FM radio. Like them, it's simply a signal modulating a carrier for transmission purposes, and detected at the receiving end to retrieve the signal. Unlike them, instead of modulating the amplitude or base frequency of a carrier, it modulates the density of pulses. This occurs as a hunting/feedback process in a Delta-Sigma Modulator, creating a pulse stream clocked at the sample rate who's density is proportional to the signal level. No frames, no words, all continuous, and most distinguishing, no weight or value! That's why it has to be either converted to PCM to be processed in a computer, or converted to multi-bit Pulse Density Modulation, ala the Sonoma DAW.

Since it by definition has only two levels, a computer can store and retrieve it, just not process it, because it does not represent actual sample values. All it represents is change of levels through the density of the pulses in a continuous pulse stream. The higher the level, the denser the pulse chain. ANALOG!

That's why you're correct saying just filter it, and get the signal back.

Wow..I have not seen it explained so clearly, thank you!!!!

 

[wisnon]

Actually, you're allot closer to being right on than you may think. DSD (1-bit two level Pulse Density Modulation) isn't digital in the first place, it's ANALOG! PCM is digital, in that it's a sequence of discrete 2's complement binary words of n bits, with each word being a stand alone digital expression of an analog signal level, at the sample time. It's just like frames of movie film, strung together to convey motion.

DSD, a Sony/Philips marketing term for a 1-bit two levels analog format is as analog as AM or FM radio. Like them, it's simply a signal modulating a carrier for transmission purposes, and detected at the receiving end to retrieve the signal. Unlike them, instead of modulating the amplitude or base frequency of a carrier, it modulates the density of pulses. This occurs as a hunting/feedback process in a Delta-Sigma Modulator, creating a pulse stream clocked at the sample rate who's density is proportional to the signal level. No frames, no words, all continuous, and most distinguishing, no weight or value! That's why it has to be either converted to PCM to be processed in a computer, or converted to multi-bit Pulse Density Modulation, ala the Sonoma DAW.

Since it by definition has only two levels, a computer can store and retrieve it, just not process it, because it does not represent actual sample values. All it represents is change of levels through the density of the pulses in a continuous pulse stream. The higher the level, the denser the pulse chain. ANALOG!

That's why you're correct saying just filter it, and get the signal back.

I know Tom. I have such a DAC…LoL I have a Lampi DSD-only Dac and I know the motion picture film analogy and why DSD is MORE bit efficient than PCM. People mistakenly think its about comparing resolution, but its about how much new info each packet in the stream brings. DSD references the CHANGE.

The philosophy for the Lampi DSD Dac is that it's essentially ANALOG and treated totally in the analog domain.
http://www.lampizator.eu/NEWDAC/Lampizator/DSD_DAC.html
http://gpoint-audio.com/our-collection/lampizator/

 

[Julf]

Wow..I have not seen it explained so clearly, thank you!!!!

And when it is explained that clearly, it is obviously wrong.

DSD is just as digital as PCM, in that the signal is stored in discrete, quantized values at a constant sample rate. Just because one system uses a higher sample rate but a smaller number of bits (1, in the case of DSD) doesn't make one "analog" and the other "digital". DSD is pulse-width modulation, but the width of the pulses can't take arbitrary analog values - the resolution of the pulse width is limited by the sample rate. Standard DSD, with a sample rate of 2.8224 MHz, thus uses a digital data rate of 2822 kBit/s per channel (comparable to the 2304 kBit/s of 24/96 PCM - but because DSD is usually considered equivalent of 20/96 PCM, we can see that PCM is somewhat more efficient).

Yes, digital PWM data is easier to convert into an analog form (all you need is a low-pass summation filter), but it still can only take set, quantified values (unlike analog that forms a continuous function that can take arbitrary values).

"DSD-wide", as used in "DSD" editing and mastering systems, is 8-bit PCM, but still at the 2.8224 MHz sample rate, while DXD is pure 24-bit PCM at 352.8 kHz.

 

[wisnon]

Ahhh Julf,

You dont even need filtration to play back DSD. Just connect it to a speaker and you get distortion filled music, so there is NO conversion going on, and thus its more analog than digital. Its a finite pulse representation of a continuous waveform without any coding.

So you are BOTH correct.

DSD is more bit efficient though, as it reports the changes from initial reference and not the status quo plus incremental change like celluloid movie recording & PCM.

 

[Julf]

You dont even need filtration to play back DSD. Just connect it to a speaker and you get distortion filled music, so there is NO conversion going on, and thus its more analog than digital.

Right, but the distortion is a hint that you are only doing part of the conversion process

Its a finite pulse representation of a continuous waveform without any coding.

As in "pulses with a finite number of widths", yes, and I guess it becomes a semantic debate about what is and what isn't "coding".

DSD is more bit efficient though, as it reports the changes from initial reference and not the status quo plus incremental change like celluloid movie recording & PCM.

How much more efficient? It is a bit tricky to compare PWM and PCM as pulse width modulation has a frequency-variable resolution, but if we take the pretty well-accepted values of "equivalent of 20 bit, 96 KHz PCM", we get 2822 kbit/s per channel of DSD vs. 2304 kbit/s of PCM, so one could say DSD is something like 22% less efficient.

That value can definitely be debated, but I would like to hear your view - how much more efficient is DSD in your opinion?