Sources for DXD

[Andrew Allen Ballew]

Other than 2l, and a few items on HighDefTapeTransfers?

 

Looking for native DXD.

 

 

Thanks

[Leroy Bad]

Remind me, isnt DXD the product of converting DSD to a high resolution PCM like 352khz or something? I remember there was something pointless about it.

[Andrew Allen Ballew]

Certainly not pointless.

 

There are native DXD recordings. See 2l.no

 

The best sounding recordings I have are DXD. 24 bit 352khz PCM.

 

 

Remind me, isnt DXD the product of converting DSD to a high resolution PCM like 352khz or something? I remember there was something pointless about it.

[Andrew Allen Ballew]

from 2l. They record natively in DXD.

 

At venue recording sessions our analogue to digital converters can do both the one-bit DSD and the multi-bit PCM formats. We can also listen directly to the analogue output from the microphones. Digital eXtreme Definition is a professional audio format that brings “analogue” qualities in 24 bit at 352.8 kHz sampling rate. DXD preserves 8.4672 Mbit/s (3 times the data of DSD) per channel. This leaves headroom for editing and balancing before quantizing to DSD for SACD or PCM for Blu-Ray.

All audio formats on The Nordic Sound are sample rate converted from the same DXD master. Comparing them in our studio we find only subtle differences from DXD down to 192kHz and 96kHz. The obvious degeneration is from 96kHz down to 48kHz. We find DSD, as used in the SACD format, somewhat different in colour from PCM; in some mysterious way DSD is softer and more beautiful but slightly less detailed. In DXD we find the shimmering brilliance from the original analogue source as directly from the microphones. Linear PCM is offered in addition to DTS HD Master Audio on this Blu-ray with the purpose of convincing audiophiles of the true lossless qualities of commercial encoding. The stereo layer of the SACD and the LPCM 2.0-stream on the Blu-ray are both full resolution mix from the original microphones. Mostly we find that the microphone placements used for the surround make a fine stereo. Occasionally we put up extra microphones dedicated for the stereo stream.

I personally prefer extremely high resolution PCM over the DSD and I would claim that DSD is not transparent. But it all comes down to what the sound from your speakers can do to your body and mind. I find that the placement of microphones has an infinite more important role in the final experience of music, than the difference between HiRes PCM and DSD. Sometimes a lie can be more beautiful than the truth!

[Leroy Bad]

Very interesting. I've never heard it explained that way before. I suppose we could experiment with that in Jriver, it can output a PCM or DSD source as 352.8khz PCM.

[Andrew Allen Ballew]

what you are talking about is valid, too though. While you can record natively in DXD it is perhaps more well known as an intermediate editing format for DSD.

[tailspn]

from 2l. They record natively in DXD.

 

No such thing as natively recorder DXD. The DAD AX-24 AD/DA converters that 2L uses are front ended with multi-bit Delta-Sigma Modulators, that are also configurable to 1-bit,two level (DSD) modulators. The conversion to DXD (352.4KHz word based PCM) is a in-the-box post process, as it is with all A/D converters manufactured in the last twenty years.

 

Morten may prefer the sonic effects of the required 8X low pass filter required in the 2.82MHz bit rate to 352.4KHz PCM word rate conversion, and you may also. I don't.

[Hiro]

Remind me, isnt DXD the product of converting DSD to a high resolution PCM like 352khz or something? I remember there was something pointless about it.

 

Most PCM AD converters operate in a similar way, not just the "DXD" ones.

 

Take for example the Mytek 8X192 ADC. The converter uses 1bit sigma-delta chips operating at 128fs, so you can use it to either record directly to DSD at 128fs or downsample the SDM stream to 1fs/2fs/4fs PCM.

[elcorso]

Sometimes a lie can be more beautiful than the truth![/font][/color]

 

Depends, what is truth and what is the lie? We then go to the individual tastes of each. I personally like better DSD than PCM.

 

I always try to compare recordings to live music playback. If you believe that DSD has less "detail", I think it has the right "detail", no less. This may depend on the recording itself, such as microphones, etc. And of course the listening gear.

 

I can congratulate 2L for providing excellent recordings, but I do not like the SQ of DXD (or DSD from DXD).

 

Roch

[Andrew Allen Ballew]

I know that the A/D in the Pyramix is multibit delta sigma. It is obvious if you look at the spectral content. I suppose you are correct that it is not "native" PCM. But as you pointed out, this is standard fare.

 

How about this... other places that provide DXD, as the first format after the A/D converter? (regardless if the ADC is Delta Sigma or true multi bit PCM)

 

As far as 2L is concerned, since they record this way, the DXD is the most native form you can buy.

And furthermore, the multi bit delta sigma A/D has WAY more amplitude and time resolution that either DSD or DXD can carry. If you could buy (not to mention play back) that data stream, I would.

 

 

 

 

 

 

No such thing as natively recorder DXD. The DAD AX-24 AD/DA converters that 2L uses are front ended with multi-bit Delta-Sigma Modulators, that are also configurable to 1-bit,two level (DSD) modulators. The conversion to DXD (352.4KHz word based PCM) is a in-the-box post process, as it is with all A/D converters manufactured in the last twenty years.

 

Morten may prefer the sonic effects of the required 8X low pass filter required in the 2.82MHz bit rate to 352.4KHz PCM word rate conversion, and you may also. I don't.

[Hiro]

As far as 2L is concerned, since they record this way, the DXD is the most native form you can buy.

 

If they are using an SDM-to-PCM converter then the PCM files are not native. They are a product of digital low-pass filtering, downsampling, and PCM decimation filtering of the SDM signal.

[Andrew Allen Ballew]

Sure! But the closest thing to the original source you can buy from 2l is the DXD! Their signal chain looks like this...

 

Delta Sigma ADC- multibit PCM.

 

Everything else they sell is converted from the multibit PCM. You can't get any closer to the native data stream than the 24 bit, 352.8 kilohertz PCM...

 

look the bottom line is I think that as far as delivery formats go, 24 bit 352.8 khz PCM is tops to my ears. Better than 1 bit DSM. Furthermore, I believe in buying the format closest to the source with the least amount of conversions possible.

 

In this case, it is DXD. Which is good, since I believe that is the highest fidelity format we can use at home.

 

As another example, if at 2L they converted to one bit DSD immediately after the multibit DS ADC, then I would want to buy that, as that would be superior to any following PCM conversion. Conversion = data loss.

 

So two things are at work here.

 

Closest to the native data with the least amount of conversions.

 

High resolution PCM, if that is possible.

 

Again, with the 2L recordings, the closest you can get to the native data is the DXD. It is the first conversion after the multibit delta sigma. If you buy DSD from 2l, it is another step down the signal chain.

 

To be fair, I would love to hear what the 2l recordings would have sounded like if they had gone native delta sigma the entire way. But they didn't.

[Hiro]

Sure! But the closest thing to the original source you can buy from 2l is the DXD! Their signal chain looks like this...

 

Delta Sigma ADC- multibit PCM.

 

Everything else they sell is converted from the multibit PCM. You can't get any closer to the native data stream than the 24 bit, 352.8 kilohertz PCM...

 

You can, by offering native 128fs SDM output from the Sigma-Delta modulator. When you convert the output of sigma-delta modulator to PCM you can't call the resulting file native anymore.

[tailspn]

As far as 2L is concerned, since they record this way, the DXD is the most native form you can buy.

 

I don't know what you mean. 2L chooses to output of their DAD AX-24, DXD format, which involves internally converting the Delta-Sigma Modulator to DXD (PCM) via an extra process in the ADC. That's their choice. And IMO, it's to provide marketing differentiation. They could just as easily configure the the AX-24 to output DSD, and skip the conversion step.

 

Their acoustic music catalog does not/should not require significant post processing, other than editing (which on a Pyramix can be preformed in pure DSD mode via their internal Philips software modulator). 2L doesn't do Pop music, requiring effects processing, which is the valid reason for converting to DXD.

 

 

And furthermore, the multi bit delta sigma A/D has WAY more amplitude and time resolution that either DSD or DXD can carry. If you could buy (not to mention play back) that data stream, I would.

 

 

That's not correct. First off (and you didn't say or imply this) multi-bit Pulse Density Modulation is not PCM. It's a parallel bit, word stream, modulated by the instantaneous level of the driving analog signal, changing the density of bits in the bit streams. Unlike the bit depth of PCM, for a given bit rate, multi-bit two level has the same time and amplitude resolution as 1-bit two level (DSD). Also, unlike PCM, what is doesn't have is an instantaneous digital value expressed by it. What it does have is a binary relationship between the parallel bit streams that makes it compute-able.

 

DXD and DSD do sound different. DXD is sharper and more vibrant, like PCM. But it's certainly not more accurate to the incoming analog signal. Nor is it "native". There is no such thing as a native PCM A/D converter used today, and hasn't been since the dawn of the digital era. A true PCM ADC can hardly do 12 bits of resolution given component tolerances. They are what gave CD's the bad rap they originally enjoyed.

 

My only comment here is over the term "native" DXD. No such thing. DXD is derived from 1 or multi-bit Delta-Sigma Modulation, no matter if it's in the A/D converter box, or later computed in the editing workstation software.

[Jud]

Hi Andrew. tailspn works for Channel Classics and knows a little about A/D equipment and the way it's used by various studios/labels.

[Andrew Allen Ballew]

2l chooses to use DXD output from their DSM ADC. The other choice is one bit DSD.

 

In either case there is a downconversion. The DS modulator is multibit and contains 12 times the information of DSD64 and 6 times the resolution of DSD128.

 

Either way, you are losing resolution. That is a fact! Now whether this first loss sounds better converted to high bit rate PCM or 1 bit delta sigma... that can be debated.

 

I admit that you can't call this native PCM. Sorry. You are all correct on that. But you know what? You can't buy the multi bit delta sigma stream. Nor can you play it back. You can't even go back to the Hard Drive and get it. Why? Because the earilest generation that you have access to in this case is the DXD/PCM!!

 

If they chose to output the DSD128 datastream from the ADC then that would be the earliest generation you have access to.

 

I am not sure what is confusing about this? Lets just forget the whole native thing, if that is where it is coming from?

 

Futhermore, yes there are native PCM ADCs. Pacific Microsonics. There are several still out there. See Reference Recordings.

 

And as far as time and amplitude resolution, PCM vs DSD, etc. That is a whole nother can of worms that I will leave alone. lol

 

 

 

And Jud, I know who he is. I also know where I am getting my information. I respect the work he does at Channel Classics, but he isn't the only authority out there.

[Andrew Allen Ballew]

Not from 2L, that is my point! They didn't choose to output at DSD128. If you buy from 2l, the closest you can get, the "master" is in DXD.

 

 

 

 

You can, by offering native 128fs SDM output from the Sigma-Delta modulator. When you convert the output of sigma-delta modulator to PCM you can't call the resulting file native anymore.

[Andrew Allen Ballew]

Let me offer one final clarification and I am done with this thread. Too much confusion over a term I used.

 

True. You can't call native PCM native if it is sourced from a Delta Sigma modulator.

 

In my opinion, DXD is a better format than any of the 1 bit DS formats, regardless of the ADC.

 

Modern Delta Sigma converters have more resolution than any consumer level format, anyway. Again, I think their output is best delivered to the consumer in DXD. That is at least until we have a DSD format that is multibit and higher sample rate. As of now, we don't.

 

In the interest of least amount of conversion, least data loss, I am interested in buying the consumer format closest to the master file, or the master file itself, or both. Since I have already made it clear I think DXD is the way to go, that is what I am looking for.

[Andrew Allen Ballew]

And finally, are you slipping Jud some extra cash, tailspn? It seems like he constantly finds it necessary to point out who you are to us plebeians.

 

I am kidding of course. I just tire of people who make assumptions, among other things.

[Jud]

And finally, are you slipping Jud some extra cash, tailspn? It seems like he constantly finds it necessary to point out who you are to us plebeians.

 

I am kidding of course. I just tire of people who make assumptions, among other things.

 

Constantly? I may have done it a couple or three times out of about 5000 posts. The only person on the forums I assume is "plebeian" is the only one where I know for a fact it's true - me. Edit: Yes I know you're kidding.

[Hiro]

In either case there is a downconversion. The DS modulator is multibit and contains 12 times the information of DSD64 and 6 times the resolution of DSD128.

 

Your math seems to be a bit off. DAD AX-24 uses 5 bit delta-sigma modulator operating at 128fs. Thus, to get the native SDM (DSD) stream from the modulator's output no downsampling, digital low-pass filtering and pcm decimation filtering occurs. There's more to "resolution" than simple bitrate calculations.

 

By the way, all DSD DACs utilize either 1-bit or low-bit Delta-sigma modulators.

[Hiro]

I admit that you can't call this native PCM. Sorry. You are all correct on that. But you know what? You can't buy the multi bit delta sigma stream. Nor can you play it back.

 

The additional 4bits (yawn) in the delta-sigma modulator basically let you lower the noise floor in the above 60kHz region. I'm not going to lose sleep over this as 128fs DSD already delivers ~100dB of DR up to 80/100kHz depending on the application.

[Hiro]

My only comment here is over the term "native" DXD. No such thing. DXD is derived from 1 or multi-bit Delta-Sigma Modulation, no matter if it's in the A/D converter box, or later computed in the editing workstation software.

 

Correct.