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DSD vs PCM, bit vs hz, Is there a way to compare them fairly?
bennetng
post Jan 11 2014, 17:21
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Obviously I can't compare a hybrid SACD's PCM vs DSD layer because they can be mastered differently.

What I mean is compare them in a same bitrate. DSD is at least 2.8224mhz and the bitrate is 4x of Audio CD. I don't think it is useful to compare PCM formats such as 16-bit 176.4khz or 32-bit 88.2khz vs DSD@2.8224mhz because I can't even ABX 16/44 vs 16/48. A more reasonable comparison would be 16-bit 44.1khz vs DSD@705.6khz or lower.

Another question: it is possible that an "intermediate" format such as 4-bit 176.4khz could sound better than 16-bit 44.1khz if a carefully designed noise shaping/filtering algorithm is used?

Did someone make a research on such things?
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saratoga
post Jan 11 2014, 18:26
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If you want to compare, convert both to the highest settings your system supports and do an abx.

In general there is little advantage for playback when using higher than 44.1/16.
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bennetng
post Jan 11 2014, 18:52
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I did try 8-bit 88.2khz vs 16-bit 44.1khz by using Adobe Audition 1.5 and foobar2000 as my soundcard supports up to 24bit 96khz, but the problem is that I can only use the noise shaping algorithms provided by those software, I don't have the ability to design the algorithms myself so it is very difficult to make a fair comparison.
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lvqcl
post Jan 11 2014, 19:00
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Build your own noise shaping filters!

(the program is attached to post #17)
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[JAZ]
post Jan 11 2014, 19:09
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You obviously need to compare the formats in the context of what they are expected to maintain:

From the article of DSD in wikipedia:
QUOTE
Because of the nature of sigma-delta converters, one cannot make a direct comparison between DSD and PCM. An approximation is possible, though, and would place DSD in some aspects comparable to a PCM format that has a bit depth of 20 bits and a sampling frequency of 96 kHz.[23] PCM sampled at 24 bits provides a (theoretical) additional 24 dB of dynamic range.


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bennetng
post Jan 11 2014, 19:22
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@lvqcl: Thanks so that I can do some experiments cool.gif
@[JAZ]: Then it seems that DSD is less efficient than PCM (at least in the research mentioned in wikipedia)?
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saratoga
post Jan 11 2014, 19:34
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Yes, DSD is essentially dead for various reasons, one of which was how well PCM works.
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Woodinville
post Jan 17 2014, 00:37
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***sigh***

DSD is a kind of pcm.



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bennetng
post Jan 17 2014, 02:07
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Not PWM or PDM?
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wnmnkh
post Jan 17 2014, 02:57
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QUOTE (saratoga @ Jan 11 2014, 13:34) *
Yes, DSD is essentially dead for various reasons, one of which was how well PCM works.


It is not really dead anymore, with recent CES I've attended this year, I saw a tons of new DACs and stuffs supporting DSD, DXD and other unicorn audiophile formats.

You can grab one that can capable of playing DSD for as low as 150 USD from Schiit Audio.
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eahm
post Jan 17 2014, 03:32
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Just talking from a business view of the situation, people/companies invest badly all the time, a new or ten new products don't really mean anything. I don't know if it's dead or not but that certainly doesn't prove it's not dead. For example, did you see new 3D TVs as well?

This post has been edited by eahm: Jan 17 2014, 03:32


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Kohlrabi
post Jan 17 2014, 07:07
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QUOTE (Woodinville @ Jan 17 2014, 00:37) *
DSD is a kind of pcm.
Please elaborate on that. It's certainly not obvious, for at least all of the online sources I searched so far differentiate between PCM and PDM.


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Arnold B. Kruege...
post Jan 17 2014, 18:12
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QUOTE (wnmnkh @ Jan 16 2014, 20:57) *
QUOTE (saratoga @ Jan 11 2014, 13:34) *
Yes, DSD is essentially dead for various reasons, one of which was how well PCM works.


It is not really dead anymore, with recent CES I've attended this year, I saw a tons of new DACs and stuffs supporting DSD, DXD and other unicorn audiophile formats.

You can grab one that can capable of playing DSD for as low as 150 USD from Schiit Audio.


That's probably because its not much that trouble to add DSD support to a sigma delta DAC chip, and audio manufacturers like to add alphabet soup to the descriptions of their products.
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includemeout
post Jan 17 2014, 20:38
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QUOTE (wnmnkh @ Jan 16 2014, 23:57) *
QUOTE (saratoga @ Jan 11 2014, 13:34) *
Yes, DSD is essentially dead for various reasons, one of which was how well PCM works.


It is not really dead anymore, with recent CES I've attended this year, I saw a tons of new DACs and stuffs supporting DSD, DXD and other unicorn audiophile formats.

You can grab one that can capable of playing DSD for as low as 150 USD from Schiit Audio.

OT I know, but It seems to me it's not only format names which are unicorn-like, as I can't help thinking the Schiit folks were really having a laugh/taking the wee at all audiophools when they came up with that horrid name o' theirs - even if it (probably) is their family name.

This post has been edited by includemeout: Jan 17 2014, 20:41


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user1
post Jan 18 2014, 03:35
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Since it's much simpler nowadays to 'throw in' DSD using inexpensive soft-/hardware ... why not toss it into a device or software-player (JRiver?) ...

Caylx (Korea?) is soon releasing a $$$ portable device -- like AK120 -- that'll do double DSD. Also the latest Sony portable headphone amp/DAC can do double DSD. Plenty of attn. at RMAF. Search YouTube for RMAF panel disc. on DSD.

Have a cookie...
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alexeysp
post Jan 18 2014, 19:58
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QUOTE (Kohlrabi @ Jan 17 2014, 09:07) *
QUOTE (Woodinville @ Jan 17 2014, 00:37) *
DSD is a kind of pcm.
Please elaborate on that. It's certainly not obvious, for at least all of the online sources I searched so far differentiate between PCM and PDM.


The presence of a noise shaper turns it into PDM. But essentially it's just a highly oversampled PCM stream with a very low resolution of the pulse magnitude representation.
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Woodinville
post Jan 19 2014, 03:54
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QUOTE (bennetng @ Jan 11 2014, 10:22) *
@lvqcl: Thanks so that I can do some experiments cool.gif
@[JAZ]: Then it seems that DSD is less efficient than PCM (at least in the research mentioned in wikipedia)?


Because DSD has each bit providing an additive refinement, and PCM has each bit providing a geometric refinement, DSD must be less efficient in some senses.

Were you to add a bit to the DAC resolution, that would be an increase in efficiency vs. doubling the bit rate of temporal refinements.

This post has been edited by Woodinville: Jan 19 2014, 03:56


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Woodinville
post Jan 19 2014, 03:58
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One could, (and some have) as well added noise shaping (also called A*PCM in Jayant and Noll) or "Sigma-Delta" or "Delta-Sigma" depending on author to standard pCM and have noise-shaped PCM.

But the dacs in use nowdays are all 1-bit to 4-bit dacs using noise shaping and massive oversampling in order to give the proper resolution at low frequencies.

You can see a slide deck at www.aes.org/sections/pnw/ppt.htm on conversion that will help explain this.


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julf
post Jan 19 2014, 21:34
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QUOTE (Woodinville @ Jan 19 2014, 03:58) *
You can see a slide deck at www.aes.org/sections/pnw/ppt.htm on conversion that will help explain this.


Thanks for that link - I especially enjoyed the Hayser Lecture presentation.
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AstralStorm
post Feb 12 2014, 05:49
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The final point is that the formats are more or less equivalent. Which means you shouldn't pay through the nose for DSD material.

However, I'd say that excellent R2R DACs (say, old AKM or TI PCM series) are better than some otherwise excellent sigma-delta DACs (such as Cirrus Logic, Wolfson or ESS; sigma-delta AKM is indistinguishable to me from R2R). The difference is minor, but there and ABXable.
PCM is the base format for an R2R DAC, DSD is the base format for a sigma-delta DAC.
So, not all DACs are sigma-delta. Heck, for cost-no-object purposes you can make an R2R DAC at home, given precision resistors.

Most DACs which support both, handle them equally well - but there are few exceptions - mostly using ESS chips. Again, the difference is minor.
(On an unrelated note: ESS Sabre blows, it's tonally off somehow.)

This post has been edited by AstralStorm: Feb 12 2014, 06:15


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Kees de Visser
post Feb 12 2014, 11:18
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QUOTE (AstralStorm @ Feb 12 2014, 05:49) *
However, I'd say that excellent R2R DACs (say, old AKM or TI PCM series) are better than some otherwise excellent sigma-delta DACs (such as Cirrus Logic, Wolfson or ESS; sigma-delta AKM is indistinguishable to me from R2R). The difference is minor, but there and ABXable.
That's interesting. Can you give details about the ABX test ? From all I've read on HA (and elsewhere) these differences are very small and presumed below audibility thresholds.
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AstralStorm
post Feb 12 2014, 13:26
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In fact, I didn't. I only did a single-blind test there, as I had contact with the helper during the test. (but still didn't see what was connected where)
The test was Presonus FP10 (older AKM) against Lynx Hilo (CS), both used as DAC, line out to Eddie Current Super 7 amplifier, Hifiman HE-500 (modded) - switchbox in my hands, free switching until a decision. Chiptune samples.
That got 11/12 tries.
Generally I was unable to properly rate either, both sound extremely good in DAC capability, but different in timbre. FP10 sounding "thicker" while Lynx sounding "lighter", both very detailed but I'd say Lynx getting the upper hand there. Noise floor difference was masked by EC S7 noise floor, which is slightly audible (-90 dB or so) - but few amplifiers do better than -108 dB anyway which is the FP10s DAC limit. (Tested via loopback into Lynx, which is superior there.)
I've checked whether frequency response matches, it was linear on both. Volume was matched using a voltmeter on 1kHz sine to within 0.5% - the knobs on FP10 didn't allow a better match.
The "better" part is kinda in air quotes in the above post. The only clearly audibly inferior DAC was the Anedio D2 loaner based on ESS Sabre 9018 - but I didn't bother to blind test it. I haven't heard such grainy treble in a while - something must be messed up in the filter.
Considering all the reviews, I bet Sabre 9018 is just a terrible chip, even in the best of implementations. Unfortunately many DACs use it.

This post has been edited by AstralStorm: Feb 12 2014, 14:21


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mzil
post Feb 12 2014, 16:46
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^Since the tube headphone amp mentioned has only one input, I take it your A/B switchbox was mounted before it in the chain and your helper manually reconnecting it, each trial, was your "randomizer". Did you have to hand this switchbox back to your assistant (helper) each time [or was what you held in your hands simply a remote control of it] and what brand/model was the switchbox, or do you have more details on it if was homemade. Thanks.

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krabapple
post Feb 12 2014, 18:49
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QUOTE (AstralStorm @ Feb 12 2014, 08:26) *
In fact, I didn't. I only did a single-blind test there, as I had contact with the helper during the test. (but still didn't see what was connected where)
The test was Presonus FP10 (older AKM) against Lynx Hilo (CS), both used as DAC, line out to Eddie Current Super 7 amplifier, Hifiman HE-500 (modded) - switchbox in my hands, free switching until a decision. Chiptune samples.
That got 11/12 tries.
Generally I was unable to properly rate either, both sound extremely good in DAC capability, but different in timbre. FP10 sounding "thicker" while Lynx sounding "lighter", both very detailed but I'd say Lynx getting the upper hand there. Noise floor difference was masked by EC S7 noise floor, which is slightly audible (-90 dB or so) - but few amplifiers do better than -108 dB anyway which is the FP10s DAC limit. (Tested via loopback into Lynx, which is superior there.)
I've checked whether frequency response matches, it was linear on both. Volume was matched using a voltmeter on 1kHz sine to within 0.5% - the knobs on FP10 didn't allow a better match.
The "better" part is kinda in air quotes in the above post. The only clearly audibly inferior DAC was the Anedio D2 loaner based on ESS Sabre 9018 - but I didn't bother to blind test it. I haven't heard such grainy treble in a while - something must be messed up in the filter.
Considering all the reviews, I bet Sabre 9018 is just a terrible chip, even in the best of implementations. Unfortunately many DACs use it.



Not good enough, sorry.
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Wombat
post Feb 13 2014, 02:09
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Shouldn't the tube amp adding more own distortion by design as any modern DAc should?
How can someone rate the source at all with a tube amp behind, leave alone assigning it to PCM, DSD or filtering?
Did i simply get the test setup wrong?

This post has been edited by Wombat: Feb 13 2014, 02:09
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