To DSD or not to DSD?

[Miska]

In order to really compare them you need to use a real multibit DAC (I have TDA1541, PCM61) followed by a fast I/V stage (I have 20V/us OpAmps).

 

That's way too slow. I have 600 V/µs on my old PCM63P converter and the newer ones use 2000 V/µs amps. Settling time must be in nanoseconds.

[mav52]

Fact #1 Readily available DSD-ready software player offers DSD64 to DSD128 and DSD256 upsampling

Fact #2 First record labels are starting to offer DSD128 recordings

Fact #3 There are people archiving LPs to DSD128

 

I think that is your opinion, but do you really have any market data that supports what your saying... what you said was

Like I said earlier the market for the higher DSD sampling rates is potentially bigger than for 64fs which Benchmark already supports.

 

When you note market I guess I assumed you have some "market data" to support the statement. Anyway carry on. A very interesting thread.

[bdiament]

Hi Hiro,

 

Barry, I don't attribute any words to you at all (I wouldn't dare to do any such thing). It's true that you said that 24/192 PCM via the ULN-8 sounds transparent to your mic feed. It's just that it's an SDM based 128x oversampling DAC.

 

When someone starts a sentence with "To Barry Diament", they are attributing what follows to me.

 

Yes, I referred to *one particular converter* at *one particular rate*. The fact that it happens to utilize SDM does not in any way suggest even remotely that I was talking about SDM in general (or even SDM at all!).

 

It has rubber coated knobs too but that doesn't mean I find all devices with rubber coated knobs to be transparent to my mic feed. Or that I attribute those knobs to be the reason for its quality -- any more than I attribute its use of SDM to that quality.

 

Barry

Soundkeeper Recordings

Barry Diament Audio

[Hiro]

When someone starts a sentence with "To Barry Diament", they are attributing what follows to me.

 

But what follows may not be an exact quote, right? Anyway, I'm glad that you realize that the converter is an SDM based DAC. Someone could have gotten an impression from reading PeterSt's posts that only non-oversampling DACs were any good.

[Hiro]

I think that is your opinion

 

You wanted facts and I gave you the facts.

[luka]

This discussion is becoming hard to follow due to mix up of multi-level and multi-bit SDM.

When I was referring to multi-bit, or multi-level, I was talking about the number of bits/levels in the SDM quantizer, the two being related by: bits = log2(levels). To me the two terms are interchangable since one can be derived from the other. DACs that use dynamic element matching may encode the modulator output to some other number of levels, but that is not what I was referring to.

 

I didn't say it was difficult, but making a good one would require much higher master clock frequency than currently used in DAC chips. Making it proper would also mean that the DAC chip will need at least large heat sink.

Why does 'proper' have to equate to large amounts of heat? Modern process geometries can deliver huge amounts of processing power without the need for heatsinks. In hardware you can have large numbers of highly-specialised processes running simultaneously, so you don't always need a super-high clock rate.

 

So far, all multi-level (>2) modulators I've seen in DAC chips are also really poor, but nature of multi-level reduces side effects of this.

Really poor in what way? Are you refering to the modulator or the upsampling algorithm (or both)?

 

Difference between two-level SDM and typical multi-level SDM is anyway just 14 dB.

14dB is quite a lot though, isn't it?

 

DSD is two-level 1-bit only in transport. Nothing says how many bits you use for conversion while still keeping it two-level. ... Of course you can have two-level SDM with any number of bits you desire.

I don't really understand what you are saying here. I guess you could sign-extend the DSD bitstream to fit any word length, but I don't think that's what most multi-bit DACs do. You could certainly use some of the 1-bit output elements to make some sort of analog FIR output filter. This would at least get rid of some of the quantization noise, but your 'perfect' DSD impulse response will now be replaced by the impulse response of the FIR filter.

 

...and increases non-linearity. But it's because customers seek for lower noise floor figures while being happy to trade linearity and distortion. Good side of that chip is that you can get the multi-bit SDM data output, instead of poor PCM. That's why I use it in some cases, although my primary converter uses PCM4202 at DSD128. I can then convert either one to what ever PCM or DSD in software.

Well, if the TI data sheets are to be believed, the multi-bit output of the PCM4222 has lower noise AND lower distortion compared to the 1-bit output of the PCM4202.

 

...Already the 8x filters are pathetic, and almost all chips employ just 8x + SAH. They just don't have enough clock cycles to do better. (ESS is better)

True enough, but many DACs have an 8fs input that allow most of the upsampling to be bypassed. What we need is a DAC equivalent to the PCM4222 that has a direct interface to the modulator =)

 

...DSD64 images repeat every 2.8 MHz, not every 352.8 kHz which makes quite big difference when it comes to simple analog filters.

Yes, but the DSD64 analog filter also has to filter out the shaped quantiztion noise, so it probably ends up being even steeper than the PCM image filter, especially if SAH stages are replaced by proper filters.

 

Another DAC... Not really much of a difference between noise output. But DSD128 gives much less time domain distortions, plus a bit lower THD and especially IMD in audio band.

Nice plots. Not much between them in terms of out-of-band noise. What DAC was this from?

 

I guess the point I'm trying to make here is that 1-bit sigma-delta no longer represents the state-of-the-art in either DAC or ADC design, so why introduce a 'new' format that is based on out-of-date technology. I can see why HiFi companies and specialist record labels would like DSD it as it gives them a chance to differentiate their products and sell more kit, but it is not really pushing the envelope over what can currently be achieved by 192kHz/24bit PCM. As music consumers, we should be much more concerned with the quality of the recording/production/mastering process and less concerned with what is essentially 'packaging'.

 

Enjoy the music!

[mav52]

You wanted facts and I gave you the facts.

 

It's still your opinion.

[Hiro]

It's still your opinion.

 

Here are the three facts again:

 

Fact #1 Readily available DSD-ready software player offers DSD64 to DSD128 and DSD256 upsampling

Fact #2 First record labels are starting to offer DSD128 recordings

Fact #3 There are people archiving LPs to DSD128

[Hiro]

I guess the point I'm trying to make here is that 1-bit sigma-delta no longer represents the state-of-the-art in either DAC or ADC design, so why introduce a 'new' format that is based on out-of-date technology. I can see why HiFi companies and specialist record labels would like DSD it as it gives them a chance to differentiate their products and sell more kit, but it is not really pushing the envelope over what can currently be achieved by 192kHz/24bit PCM.

 

FYI

 

http://www.computeraudiophile.com/f15-music-general/worlds-highest-resolution-recording-16011/

[Hiro]

And BTW, don't forget that 64x/128x/256x DSD DACs support the legacy PCM format too. It's just that they are giving audiophiles the chance to listen to DSD recordings without downsampling them to 2x/4x PCM.

[Jud]

True enough, but many DACs have an 8fs input that allow most of the upsampling to be bypassed.

 

Wish I'd had you around when I was looking. Had God's own time finding one of these "many" DACs that accept 8x rates and convert from D/A at those same rates in my price range, and when I did it was actually a bit of an accident (unpublicized upgrade).

 

I can see why HiFi companies and specialist record labels would like DSD it as it gives them a chance to differentiate their products and sell more kit, but it is not really pushing the envelope over what can currently be achieved by 192kHz/24bit PCM. As music consumers, we should be much more concerned with the quality of the recording/production/mastering process and less concerned with what is essentially 'packaging'.

 

Enjoy the music!

 

There are a number of folks in the thread who hear it as more than packaging. Some like DSD less than 24/192, some more (the latter including me, in careful listening to 24/192 and DSD files taken from what I believe to be the same master).

 

And I very much agree with you that this is all in service of enjoying the music, which I do on PCM, DSD, and vinyl.

[bdiament]

But what follows may not be an exact quote, right?...

 

 

Do you really not understand?

Once you use someone's name you are making an *attribution*.

Jeez! I really don't get why you're having so much trouble with this.

 

Okay. I'm going to make it really easy.

I keep asking and you keep missing it so I'm going to say it as plainly as I know how:

Please do not use my name or refer to me in any of your posts.

 

I would hope you are able to support your contentions without invoking my name.

And I hope this can now be put to rest and that at last, you get it: Leave me out of your arguments.

 

Folks, in case he really doesn't get it, I would ask that you simply assume any references to me in Hiro's posts are his words and not mine. They reflect his views and not mine.

 

Best regards,

Barry

Soundkeeper Recordings

Barry Diament Audio

[Hiro]

Do you really not understand?

Once you use someone's name you are making an *attribution*.

Jeez! I really don't get why you're having so much trouble with this.

 

Okay. I'm going to make it really easy.

I keep asking and you keep missing it so I'm going to say it as plainly as I know how:

Please do not use my name or refer to me in any of your posts.

 

Why so aggressive? Have I even said anything that wasn't factual? No, I haven't.

 

The ADCs/DACs you are using for Soundkeeper recordings are SDM based converters. How could I have communicated this without referring to your name?

 

I'm glad you're enjoying your 128x oversampling converters, and that you find them to be transparent to your mic feed.

 

Happy listening!

[bdiament]

Hiro,

 

Why so aggressive? Have I even said anything that wasn't factual? No, I haven't.

 

The ADCs/DACs you are using for Soundkeeper recordings are SDM based converters. How could I have communicated this without referring to your name?

 

I'm glad you're enjoying your 128x oversampling converters, and that you find them to be transparent to your mic feed.

 

Happy listening!

 

It isn't "aggressive". It is frustrated that you just don't get it.

Yes you *did* say something that wasn't factual. Haven't you read any of my responses?

 

There is no need for you to communicate anything about *my* experience. I'm fully capable of doing that on my own, thank you. Please stick with your own experience.

 

I'm going to leave it here, before it does become aggressive.

I've asked you to leave me out of your posts and hope you can muster the confidence to make your points without invoking me in any way. I hope you can find the strength to do that.

 

As far as this, over and out.

 

Best regards,

Barry

Soundkeeper Recordings

Barry Diament Audio

[PeterSt]

But what follows may not be an exact quote, right? Anyway, I'm glad that you realize that the converter is an SDM based DAC. Someone could have gotten an impression from reading PeterSt's posts that only non-oversampling DACs were any good.

 

Hiro, maybe you missed that the Phasure NOS1 may be NOS all right, but please don't miss the fact that I claim it *requires* a reconstruction filter anyway (which I propose in-PC software). Or did you really think something like 0.00076% THD+N was possible without such a filter ?

 

It may not be important, but right now I'm just going along with those who may find that your own (not-so-right) conclusions shouldn't be put as "siggestive facts" to others.

 

That's all. Thanks,

Peter

[Hiro]

Haven't you read any of my responses?

 

I have, and as you've already admitted that the converters you're using for 24/192 recordings are SDM based converters, I really have nothing more to say. Thank you.

[Hiro]

don't miss the fact that I claim it *requires* a reconstruction filter anyway (which I propose in-PC software).

 

Thanks. Interesting.

[Hiro]

It may not be important, but right now I'm just going along with those who may find that your own (not-so-right) conclusions shouldn't be put as "siggestive facts" to others.

 

PeterSt, was it my conclusion?

 

"But I also did not tell (in this thread) how any SDM based DAC (PCM output) sounds total sh*t to me. This, of course, is for the very same DACs which sound all perfectly okay to you (all)."

[Hiro]

Enjoyed following the arguments of your theory (to the degree that I could understand :0) ), but you end up bringing into question all that you have stated with, "No smashes on cymbals at all". This is indicative of such a severe bias that objectivity cannot be present.

 

The cymbals are there, in spades, and the quality of such sounds with DSD are stunning. This is assuming a proper recording, with equipment that is up to the task. This fact is clear, "to anyone that listens". That someone would deny this, flies in the face of reality.

 

I agree.

[PeterSt]

Originally Posted by SoNic67

In order to really compare them you need to use a real multibit DAC (I have TDA1541, PCM61) followed by a fast I/V stage (I have 20V/us OpAmps).

 

That's way too slow. I have 600 V/µs on my old PCM63P converter and the newer ones use 2000 V/µs amps. Settling time must be in nanoseconds.

 

Haha, this is almost not fair. I was the one who said "20 fold" based upong a 1V story implying infite rise time, but I really just mentioned "some" number. Im realilty it's 640V/us so I should have said "640 fold". This is still a bit underrated for optimal performance ...

 

20V/us indeed it way too slow. This implies slewing all over the place. Regard that as mere distortions on the transients.

 

(not an easy subject again, because with ringing filters the transients may be flattened such that a slower slew rate is quite harmless)

 

Regards,

Peter

[bdiament]

...I really have nothing more to say. Thank you.

 

I can only hope.

[Hiro]

I can only hope.

 

I hope you aren't angry with me because I brought the info up, and that it won't affect your enjoyment of the converters in any way.

[Jud]

I hope you aren't angry with me because I brought the info up, and that it won't affect your enjoyment of the converters in any way.

 

I doubt you have much to worry about on that score.

[bdiament]

Hi Hiro,

 

I hope you aren't angry with me because I brought the info up, and that it won't affect your enjoyment of the converters in any way.

 

I don't like folks attributing words to me that are not mine. I further find it frustrating when they just don't understand what I keep repeating and insist on using words they attribute to me to make their own arguments.

 

I can assure you that you have no effect whatsoever on my enjoyment of the gear I'm using.

I hope you attain the same confidence in your own choices. When that happens, you won't have to "shout" them so much.

 

Best regards,

Barry

Soundkeeper Recordings

Barry Diament Audio

[PeterSt]

Enjoyed following the arguments of your theory (to the degree that I could understand :0) ), but you end up bringing into question all that you have stated with, "No smashes on cymbals at all". This is indicative of such a severe bias that objectivity cannot be present.

 

Severe bias ?? well thank you.

But FYI : I compare with the real thing only (like the drumkit I bought for the purpose). Get out your SPL meters and notice that a live piano (wing, which I also have around here) is 90dBSPL (fine) while live cymbals are ~110dBSPL. So, tune the output to a piano showing 90dB and let me now what the cymbals show in the same track.

 

Not that we would like that much in our living rooms. I'm only saying that I ought to know a bit what I'm doing.

But for comparison, brushes from good Redbook (non-DSD based) (here !) show about the same SPL as cymbals from Hires SACD. This may sound crazy, and probably you'd have to seek for the brushes in the first place.

And *if* you receive some SPL from cymbals, be very careful to have them not hurting your ears in the wrong way.

 

With all the various "outputs" from different brands and types of DACs I can easily give examples how they will come across. So again I think I know what I'm doing and saying, but please allow me to refrain from pointing those out (I think I am on the edge with my posts already anyway, thinking about self-advertising and such).

The (or at least my) subject is about what is better, which for me is about endless comparisons between basics and theories with the notice that actually nothing can't be compared for theories really. And at least what I am doing/using is totally different from what anyone uses. I think this is important feed for the thread and which *allows* me to judge differently from others. And this is sure not because I am biased. It's actually the worst curse you can put on me.

Not that anyone will care ... :-)

 

Peter