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Picked Up my 1st DSD DAC. Verry Interesting.

107.145.111.207
Posted on June 9, 2024 at 11:52:51
Freo-1
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 Been curious about upscaling DSD DACs for some time. The idea of upscaling CD to DSD as always intrigued me. My experience is SACD has always sounded better than CD of a given recording.

I obtained the PS Audio Direct Stream Digital (the MK 1 version) with the Sunlight firmware drop, along with the Bridge ethernet card. Been very impressed with the overall performance. It does sound very different from the AKM/ESS DAC's I've owned or auditioned. To me, it's a step up from the Benchmark, RME, etc. DACs. Does an excellent job with Redbook CD upscaling to DSD. Zero harshness. Some of cleanest treble I've heard from digital to date. Low level detail is outstanding.
The DAC sounds smooth and refined. Instruments and vocals sound very natural. No sibilance from the DAC itself, any sibilance heard is from the recording.
The background is very dark and quiet. Nice wide and deep soundstage, more so than the Chord Hugo DAC's. With the Sunlight version, It more than holds its own against the Chord TT2. SACD has been accused of sounding too soft compared to PCM. That is not the case here. Plenty of dynamic contrast, Stand up Bass sounds very natural and well defined. Drum smacks have plenty of slam and impact. Pianos and wind/horn instruments sound natural as well.
The Direct Stream DAC has elevated my headphone experience to a new height of enjoyment. The price of these has come down enough to make it an excellent buy. Will use this occasionally with a tube setup as well.

Having owned the Chord Hugo TT2/M-Scaler setup, this is a cost effective alternative for upscaling. Would like to see more DAC's that upscale to DSD for playback. I think some of the Lumin DAC's support this.
" Don't look back. Something may be gaining on you"

Satchel Paige

 

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RE: Picked Up my 1st DSD DAC. Verry Interesting. , posted on June 9, 2024 at 16:28:56
boogyman
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 Congratulations.

I talked to a man that bought the original PS Audio Directstream awhile back some years and he said it was the best that he had heard.

I've always been a fan of the DSD sound myself. I believe SACD is DSD64, that's my experience with it.

 

SACD is DSD64. (NT), posted on June 9, 2024 at 17:37:14
Kal Rubinson
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RE: Picked Up my 1st DSD DAC. Verry Interesting. , posted on June 9, 2024 at 17:39:42
Freo-1
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 Thanks. I tend to agree that it may be among the best DACs available.

Products such as this and Chord shows that sites such as ASR need to be not taken all that seriously. They whine about measurements with high end DACs that clearly sound better, and push chi-com gear that sounds harsh (not natural), based on their measurements?

When in doubt, believe what you hear, not what you read, especially from reviewers.
" Don't look back. Something may be gaining on you"

Satchel Paige

 

"ASR need to be not taken all that seriously" , posted on June 10, 2024 at 08:40:11
Mel
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 Indeed. They push the stuff that sounds like crap and can put out of business the components with great sound.

There are often very good reasons why components that sound good do not "measure" as well as the cheap stuff.

 

A Step above RME? Should be a whole bunch of steps, posted on June 10, 2024 at 09:31:37
oldmkvi
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 considering the Price Difference!
I use HQ Player for PCM and DSD Conversion.
Miska says the Software should do the work, not the Dac.
I don't know how it could be combined with a DAC that also Upsamples.
Well, there is a setting for No conversion in the software.
That should work.

 

Do you have any specific examples to bolster your generalizations?, posted on June 10, 2024 at 16:46:17
Chris from Lafayette
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 Or do some listeners just LIKE distortion and noise? ;-)

 

RE: Do you have any specific examples to bolster your generalizations?, posted on June 10, 2024 at 17:28:44
Freo-1
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 You mean the distortion from the lack of filtering from mass market DACs that makes them sound harsh? Rob Watts correctly points out that many digital DACs sound rough. The DACs that look like stepped square waves vice a smooth analog signal?

Check out the review linked. There are other reviews with vey positive evaluations of the DirectStream DAC.

The major reason this DAC, along with Chord DACs, sound better than most DACs is the custom filtering, which the meter crowd totally miss. They simply can't figure how to adequately capture these characteristics.

Maybe some prefer the stepped sinewaves of the off the shelf DAC chips over the smooth outputs from the FPGA offerings? If they haven't auditioned the better FPGA DACs, how would they know any better? (They wouldn't).
" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: Do you have any specific examples to bolster your generalizations?, posted on June 10, 2024 at 23:49:56
Mel
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 First, who are you?

Some people think that some components using tubes sound more like music than some other components using only SS. Tubes usually have more measured distortion than SS components.

Some people think that some vinyl sounds more like music than digital. Vinyl clearly has more measured distortion.

Some people, and designers, think that components with no, or very low level, feed-back sounds more like music than components with high levels of feed-back which will always have lower levels of measured distortion. High levels of feedback yielding very low distortion produces sound that is threadbare and uninteresting. Its adherents will call it "clean" and think they have reached Nervana. But it is not music.

By "music" I mean unamplified instruments in real space.

Which is to say, that if your measured distortion doesn't correspond with what you hear, you're measuring the wrong thing. And that's the problem with Amir. He measures, but he doesn't listen. He's always measuring the wrong thing.

 

So IOW, it's just as I suggested?, posted on June 11, 2024 at 01:44:16
Chris from Lafayette
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 Some people LIKE added distortion and noise?

 

So help me out here, posted on June 11, 2024 at 01:49:23
Chris from Lafayette
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 Which products produce stepped sinewaves? Please provide specific names, if possible!

 

RE: So IOW, it's just as I suggested?, posted on June 11, 2024 at 02:12:04
Mel
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 Sure Chris, you're always right. Here and elsewhere.

My sympathies to Mrs. CfL.

 

RE: So help me out here, posted on June 11, 2024 at 03:07:54
John Elison
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 What's a stepped sine wave?

 

RE: A Step above RME? Should be a whole bunch of steps, posted on June 11, 2024 at 06:33:19
tlea
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 Used PS Audio DirectStream MK1 are selling in the $1500 range these days since the new model came out. Not a whole lot more than RME ADI-2.



. . . in theory, practice and theory are the same; in practice, they are different . . .

 

RE: So help me out here, posted on June 11, 2024 at 06:51:27
Freo-1
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 Ask, and ye shall receive.

Watch this video, and you should get the gist of the issues.

DSD is just another method to work around the limitations of PCM being processed by off the shelf DAC chips.

ASR measurements to my thinking need to be taken with grains of salt, and their conclusions can be misleading. A prime example of this can be seen in this interview with Rob Watts and Passion For Sound.

https://www.youtube.com/watch?v=orXrRwP7xLE



" Don't look back. Something may be gaining on you"

Satchel Paige

 

Yep. , posted on June 11, 2024 at 07:07:01
Freo-1
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 I got mine with a Bridge Network card (like new) for under 2K.

I had a RME ADI-2, and whilst it was nice, the DirectStream DAC is big step up.
" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: So help me out here, posted on June 11, 2024 at 07:45:13
John Elison
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 Well, I watched the short video about the operation of a Chord DAC, but I didn't see anything about a stepped sine wave. Can you just explain what you mean by a stepped sine wave. All the DACs I've ever owned produced ordinary analog sine waves. Of course, I've never owned a Chord DAC. Do they produce stepped sine waves?

Thanks!
John Elison

 

RE: So help me out here, posted on June 11, 2024 at 08:45:24
Freo-1
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 If you look at the video, one sees the stepped pulses connected via filtering. The stepped sine wave is a bit tongue in cheek, referring to sub optimal filtering. Some DAC measurements show a bit of a stepped looking sine wave vs. a smooth sine wave.

Here is a quick synopsis from AI regarding FPGA DACs:

FPGA DACs offer several advantages over traditional DACs, including:

Flexibility: FPGA DACs can be reprogrammed to perform a wide range of signal processing tasks, allowing for customization to meet specific audio system requirements.
Higher quality audio: FPGA DACs can provide improved signal-to-noise ratios and lower distortion, resulting in higher quality audio output.
Real-time processing: FPGA DACs can perform real-time signal processing, making them suitable for applications where low-latency is important, such as live sound reinforcement or gaming audio.
Cost-effectiveness: FPGA DACs can be more cost-effective than traditional DACs, especially for high-end audio systems.
Power efficiency: FPGA DACs consume less power than traditional DACs, making them suitable for portable audio devices.
Higher sample rates and bit depths: FPGA DACs can support higher sample rates and bit depths, allowing for more accurate audio reproduction.
Customization options: FPGA DACs can be programmed to support a wide range of audio formats and sample rates, making them versatile enough to be used in various applications.


" Don't look back. Something may be gaining on you"

Satchel Paige

 

OK, I didn't realise! nt, posted on June 11, 2024 at 09:31:04
oldmkvi
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 /

 

Aha! So are you one of those people who can HEAR the stair-steps?, posted on June 11, 2024 at 11:07:36
Chris from Lafayette
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 Or do you listen with your eyes? Isn't that what you accuse Amir of doing? ;-)








View YouTube Video

Seems like the Chord people may have been able to exploit your predispositions. ;-)

 

Hey, Mel! Have a nice day! ;-), posted on June 11, 2024 at 11:11:01
Chris from Lafayette
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 And, BTW, I will defend to the death people's rights to listen to noise and distortion if that's what they prefer. ;-)

 

Overly simplistic. , posted on June 11, 2024 at 11:17:41
Freo-1
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 Single tones are not the same as music.

There are lies, damn lies, and statistics.

For a more detailed set of explanations about DACs:
" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: Aha! So are you one of those people who can HEAR the stair-steps?, posted on June 11, 2024 at 11:50:12
samstone
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 I believe that I will stick with using my ears as the final listening device. Not some useless measurement device that is ultimately meaningless.

 

"Single tones are not the same as music", posted on June 11, 2024 at 12:39:33
Chris from Lafayette
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 Yes, that is correct. So what? You didn't answer any of my questions. Do you feel that you hear the stair-steps when you listen on non-Chord equipment? Can you hear the stair-steps better with music than you can with single tones?

BTW, I found your link somewhat mystical and poorly reasoned (a la Darko). For something more grounded in reality, check this out:








View YouTube Video

 

And I will defend your right to do so (as I posted above), posted on June 11, 2024 at 12:43:16
Chris from Lafayette
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 It's just like with religion: I will defend to the death your right to believe in whatever astrology cult you might prefer! ;-)

 

So now you know more than Rob Watts?, posted on June 11, 2024 at 14:28:32
Freo-1
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 Not bloody likely. Rather arrogant approach to take.

I'll trust Rob Watts/Ted Smith over you and ASR any day of the week. They have put in the blood, sweat, and tears to make some excellent gear. Yes, its very obvious to hear the difference between the Chord DAC and a off the shelf DAC chip. There is tons of digital ink spilled over on Head-Fi.org about this. Headphone listening is much more revealing of DAC performance over standard loudspeaker playback.

Taking a small subset of incomplete measurements and declaring absolute results is not scientific. The ASR review is a bit misleading, which is why I posted the response to it.

Lies, damn lies, and statistics. We are done here.
" Don't look back. Something may be gaining on you"

Satchel Paige

 

Excuse me while I genuflect!, posted on June 11, 2024 at 17:45:12
Chris from Lafayette
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 Your latest post seems to be a variety of the "argumentum ad verecundiam" fallacy.

And you STILL haven't clarified whether you believe you can hear the supposed "digital stair-steps" on non-Chord equipment. Why did you even bring up the subject then? I suspect it was because you were star-struck by their promo videos, which attempted to show that stair-steps were part of all digital playback, but that Chord had "refined" their approach SO much that their stair-steps were MUCH tinier and less audible. LOL!

And talk about declaring "absolute results":
Headphone listening is much more revealing of DAC performance over standard loudspeaker playback."

Sez you - LOL! BTW, many years ago, I believed that myself - but I've now come to see the error of my old ways! (Well, for one thing, it depends on which headphones and which speakers, doesn't it?)

 

RE: So help me out here, posted on June 11, 2024 at 18:14:37
John Elison
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 Actually, the output from any DAC I've owned had no steps whatsoever. I've looked at the output on an oscilloscope and I've measured distortion using a spectrum analyzer. If there were even the slightest hint of steps in a DAC's sine wave output, it would produce gross distortion. However, sine wave distortion on all the DACs I've measured was below 0.01%. Many of my DACs had less than 0.005% distortion.

The output waveform from a DAC is filtered, which removes any steps. Even at 20-kHz, the sine waves from a test CD appear as perfect sine waves on an oscilloscope screen with distortion well below 0.01%, and there's only two samples per waveform at that frequency.

 

RE: Excuse me while I genuflect!, posted on June 11, 2024 at 18:19:33
Freo-1
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 Guess you are having trouble grasping the engineering behind the advancement in DACs.

Try actually listening sometime. You might be surprised.
" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: So help me out here, posted on June 11, 2024 at 18:25:26
Freo-1
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 It's all about the filtering. The FPGA approach with upscaling provides much finer resolution of the resulting analog waveform over the small amount provided by off the shelf/NOS DACs.

The stepped output was a tongue in cheek go at the folks who think custom filtering is useless, where by they use a small subset of measurements to justify flawed conclusion. Suddenly, they now know more that the real experts, based a on flawed evaluations.


" Don't look back. Something may be gaining on you"

Satchel Paige

 

It's a shame billy Mays is no longer with us, he could have voiced that promo much better., posted on June 11, 2024 at 21:29:01
13th Duke of Wymbourne
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 nt

 

Exactly - just as in the video I posted. Thank you, John!, posted on June 12, 2024 at 00:39:27
Chris from Lafayette
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I miss Billy Mays! But you're right, posted on June 12, 2024 at 00:44:05
Chris from Lafayette
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 He sure would have been perfect for that video!








View YouTube Video

 

Oh - so NOW you say it was tongue in cheek! LOL!, posted on June 12, 2024 at 00:52:27
Chris from Lafayette
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 In any case, you're free to like any DAC you want, no matter how flawed your own evaluations are and how star struck you are over a promo video. And I'll defend your right to like whatever you want too! ;-)

 

Hey - knock yourself out. I'm happy for you. . . , posted on June 12, 2024 at 00:57:52
Chris from Lafayette
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 . . . and I wish you the VERY BEST - no matter how divorced from reality your understanding is.

 

I'm not the one divorced from reality., posted on June 12, 2024 at 04:46:07
Freo-1
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 The engineers at Chord and PS Audio know FAR more about DAC design than most people, including the so called audio critics/reviewers. Arrogance is no substitute for actual knowledge. Reading a flawed review from ASR does not suddenly make you smarter than the design engineers.

Believe whatever you wish, but there is a body of evidence that suggests the DACs with advanced filtering DO sound better. For example, Stereophile DOES a creditable job with evaluations on audio hardware, and conduct a good set of measurements. Their rankings strongly suggest that FPGA filtering DOES offer sonic advantages.


" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: And I will defend your right to do so (as I posted above), posted on June 12, 2024 at 05:54:45
dgaapc7
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 It seems that all too often you follow a high minded phrase with a snide and scornful conclusion. How come?
LowIQ

 

RE: So help me out here, posted on June 12, 2024 at 06:08:38
dgaapc7
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 Dear John (heh heh) is this extended discussion referring to the output from the dac prior to the analog stage that provides the signal to the other system components or after? Not being snarky, my knowledge of digital signal production and processing is rather limited. Thanks.
As an aside, I agree with Abe C that the analog output stage of the dac probably influences the sound of the component more than anything else. Hence my first question-I really don't know enough to evaluate the output signal of a dac prior to analog conversion nor what effect differences at that stage of signal processing might have on final sound quality.
LowIQ

 

And the engineers NOT at Chord and PS Audio. . . , posted on June 12, 2024 at 12:27:33
Chris from Lafayette
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 . . . don't know a thing about DAC design?

And on one hand, you disparage audio critics and reviewers. And then you turn right around and say "Stereophile DOES a creditable job with evaluations on audio hardware".

LOL! Excuse me, Freo - I've got to get back to the real world now! ;-)

 

I apologize for being snarky sometimes, posted on June 12, 2024 at 12:30:52
Chris from Lafayette
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 I'm all too susceptible to the rhetoric and tone of the general discussion. But you're right, I should be above all that.

 

RE: I'm not the one divorced from reality., posted on June 12, 2024 at 13:41:30
13th Duke of Wymbourne
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 I never think of ASR as a subjective review site though Amir will give his impressions. And those might be clouded by expectation bias if a device does not measure well but, then, compare that to all the subjective reviewers who give stuff great reviews based on their expectation bias driven by company marketing material like the Chord video linked earlier in the thread.

The ASR DAC measurements are completely valid, they tell you very specific things about what a DAC does. It is ironic that DAVE does not measure so well as some low priced DACS that use the cheap DAC chips treated with disdain in Chord's video. Rob Watts does talk a lot about atributes, like noise floor modulation, that could be a big thing but cannot be measured. And he claims to be able hear an artifact that is -300dB (this is, of course, ludicrous). These things may be the most important aspects of a DAC but after all Chord's talk about the objective performance I'd expect them to get the obvious, measurable, things right and at least be at the top of the ASR SNR table.

As to 'advanced filtering' I am in the filter-schmilter camp. Most DACs have a digital filter to remove aliases (these are related to a stair stepped waveform, remove the aliases and you remove the stair steps. That is why you still see stair-steps in NOS DACs). Different manufacturers adopt different approaches e.g. Meridian and Ayre promoted minimum phase filters that have no pre-ringing for an impulse response. Rob Watts uses a straight forward filter but his twist is make it as close to a brick wall as possible hence his pursuit of many, many taps. His filter will pre-ring for a long time. And pre-ringing is a red herring anyway as any music signal should be band limited before sampling so it does not have any edges sharp enough to make the filters ring.

No doubt Ted Smith and Rob Watts are earnest and insightful but only the listener can determine if their products are worth the asking prices. One way to persuade the punters is to have a good back story and the whole 'FPGA' thing is part of that. I am pretty amazed there have been so many revisions of the direct-stream DAC firm ware, it kind of seems like they didn't get it right the first time, or the second time, or the third time - or is it Ted Smith's way to keep getting paid :). As an aside, Rob Watts is not an employee of Chord and lives off royalties from Chord products. Maybe Ted smith is the same. I suspect that PS Audio and Chord do not own those technologies but license them from the inventors.

 

RE: I'm not the one divorced from reality., posted on June 12, 2024 at 16:51:43
Freo-1
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 "The ASR DAC measurements are completely valid, they tell you very specific things about what a DAC does. It is ironic that DAVE does not measure so well as some low priced DACS that use the cheap DAC chips treated with disdain in Chord's video. Rob Watts does talk a lot about attributes, like noise floor modulation, that could be a big thing but cannot be measured. And he claims to be able hear an artifact that is -300dB (this is, of course, ludicrous). These things may be the most important aspects of a DAC but after all Chord's talk about the objective performance I'd expect them to get the obvious, measurable, things right and at least be at the top of the ASR SNR table."


I would proffer that the (ASR) measurements of the DAC do not tell one as much as it is inferred. For example, Chord maintains that jitter does not matter in their designs, due to the FPGA implementation. I think this subtlety is missed. Given the fact that the DAVE is considered among the very finest DACs in the world, the fact that ASR does not like the measurements tells me that something fundamental is being overlooked in the measurements. I will never forget the first time I heard a Chord Hugo 2 DAC. I was floored how much better it sounded compared to my Benchmark and RME DACs. I'm not knocking those DACs, they have excellent measured responses, and get great reviews. The Chord Hugo 2 just sounded way more like music. BTW, Rob Watts must have some method to measure noise floor modulation. That was a big tool in his filter designs. This goes back to my point about DAC measurements, some of the key factors with DAC performance are likely not being adequately captured.

I get folks are cynical when engineers go on about their designs. Having said that, the information Rob Watts puts out is largely verifiable. It is complex, but most people can grasp the concepts behind the explanations. It made me understand why the Cord DACs sounded as good as they do.


"No doubt Ted Smith and Rob Watts are earnest and insightful but only the listener can determine if their products are worth the asking prices. One way to persuade the punters is to have a good back story and the whole 'FPGA' thing is part of that. I am pretty amazed there have been so many revisions of the direct-stream DAC firm ware, it kind of seems like they didn't get it right the first time, or the second time, or the third time - or is it Ted Smith's way to keep getting paid :). As an aside, Rob Watts is not an employee of Chord and lives off royalties from Chord products. Maybe Ted smith is the same. I suspect that PS Audio and Chord do not own those technologies but license them from the inventors. "


I wondered about the constant firmware with the Direct Stream DAC as well. I held off getting one until the firmware stopped updating and the price dropped to the point it was worth trying. Having been a Devialet owner since 2016, numerous firmware updates are not a big deal to me. It is definitely a great sounding DAC. I use it primarily as the processor for a high end headphone setup, which it really shines.


" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: I'm not the one divorced from reality., posted on June 12, 2024 at 23:24:29
13th Duke of Wymbourne
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 An advantage of an FPGA based design is that you can control clock jitter everywhere whereas you cannot with DAC chips because you have no control of clock distribution inside the chip. That said, chip DAC designers know what they are doing and they won't allow the on-chip clock to limit resolution. And, further, I think the whole jitter thing is a red herring (see link) and it is only a thing for manufacturers to try to differentiate their products (except that everyone does it these days).

I do not believe Rob Watts has a method to measure noise floor modulation (I watched his latest seminar video recently, I will look again to be sure) just he has he cannot measure the diode effects in contacts that he claims are audible. These effects may be important but my point remains why aren't the obvious common-or-garden measurements also first class? If there is a reason where SINAD is compromised to optimize for something not measurable why not say that and make that a feature? And don't forget about the -300dB artifact claim he makes - he sort of shrugs it off saying 'I know it's a big number but I can hear the effect'. That is not good enough, 300dB isn't just a big number it is a very hugely massively enormous number and Rob knows that. At best he is hearing correlation not causation, at worst it is hubris that he thinks his hearing is special.

That all said I've never heard a Chord DAC and if people like them that is great. But one of my mantras is that if you like something then enjoy and don't worry about it being the best objectively because you will be disappointed to find out it is not. Like supporting a football a team, if you insist they win every match then you won't have much fun. And I'm primarily a vinyl listener, a medium that is very compromised objectively but it makes me happy.

 

RE: So IOW, it's just as I suggested?, posted on June 13, 2024 at 01:22:02
morricab
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 No, it has to do with AUDIBLE distortion. Your ear/brain have certain filters and masking processes that work wonders on removing the audibility of certain types of distortion but products that have other profiles will be exposed. Psychoacoustics is an interesting field and it leads to some rather interesting conclusions such as THD and IMD are essentially meaningless when it comes to listeners observation of what SOUNDS distorted or clean to them. Geddes found no correlation and even a slight downward trend.

Cheever went further and said that it is the harmonic components and their correct weighting that gives the best prediction and derived his equation from what is known about masking of low order harmonics and the ears own self-generated distortion.

If designers were to use psychoacoustic tools for designing their gear there would probably be a lot more good sounding gear.

The argument a lot of the extreme measuring products have is that they have pushed the distortion so low that it is "inaudible" and therefore the whole psychoacoustic issue is moot. However, there is sufficient evidence in the scientific and engineering literature that suggests that using huge amounts of negative feedback to suppress distortion harmonics damages the sound in other ways that are quite difficult to measure and won't be obvious from standard measurements. As Mel stated high feedback designs tend to sound threadbare and sometimes even harsh. Is that just revealing the "warts and all" of the recordings? If so, there are a lot of bad recordings out there. Even really good ones will suffer from this treatment. In other words, how you achieve a result is also affecting the end result...its more path dependent rather than state dependent and this is primarily due to the fact that our hearing is more than a little bit complicated...and not at all like a microphone and oscilloscope.

 

RE: So help me out here, posted on June 13, 2024 at 01:25:49
morricab
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 Not saying the PS Audio Directstream sounds bad...never heard it actually; however, I have heard other FPGA based DACs, as well as countless Sigma/delta DACS and I will stand with my "old school" Burr Brown PCM1704 24 bit R2R DAC with tube output stage...sounds more like the real thing than other digital solutions I have heard.

 

He has a current infomercial. I guess it's up to the Brit Guy to carry on!, posted on June 13, 2024 at 05:38:55
oldmkvi
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 You sure Mays is gone?

 

An instrument sustaining a long note is not music? nt, posted on June 13, 2024 at 05:41:29
oldmkvi
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 .

 

I agree that huge amounts of negative feedback are generally considered. . . . . . , posted on June 13, 2024 at 11:01:35
Chris from Lafayette
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 . . . to have deleterious effects on the sound quality. I also believe that this approach to design has ebbed quite a bit over the decades and is thus not as relevant to the discussion today as it may have been in the past.

As for "bad" recordings, it would help if you could name actual recordings which suffer from the problems you list, rather than stating generalizations.

BTW, is this the Geddes you mean (at the link below)? This particular Geddes says things like the following:
I have always thought that if someone's measurements do not "tell the whole story" then they are the wrong measurements. Technology has simply come too far to believe that "there are things that we cannot measure." I have also never believed that all that matters is "how it sounds," because this is such an unstable and personal opinion. Sound quality opinions can and will differ from person to person, system to system and most importantly even within the same person on different days (as I said before, I have personally witnessed this in well regarded "reviewers"). Personal preferences have such a low stability as to be an almost completely pointless thing to stake a claim to. "Hi-Fi" does not mean "pleasant" - it means "accurate"; accuracy, as opposed to preference, is absolutely quantifiable and extremely stable - as stable as I care to control in my lab from day to day or test to test (but in any case its uncertainty is easy to quantify and understand). Decisions based on accuracy are therefore much more likely to be valid than decisions based on "how it sounds." I do not see how one could ever support a position that "preference" trumps "accuracy." That's simply taking a giant step backwards in the evolution of Hi-Fi.

 

"You sure Mays is gone?", posted on June 13, 2024 at 11:04:48
Chris from Lafayette
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 Wikipedia says he croaked in 2009. Of course, I don't always trust Wikipedia, but that's another discussion! ;-)

 

RE: So IOW, it's just as I suggested?, posted on June 13, 2024 at 14:21:06
13th Duke of Wymbourne
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 Interesting points, I think THD and IMD are meaningless too for sound quality. I listen to vinyl mostly and that is rife with distortion, so much so that no one ever talks about it (except HFN-RR who measure distortion of cartridges. If you have to ask how much they produce then you don't want to know the answer). The weighting of harmonics was Hiraga's thing and Keith Howard did his own investigation (see link).

But what are these pyschoacoustic tools and would you really want every piece of gear to sound great? Good sound would be a commodity and people would only then choose by features and price. The high-end would disappear (maybe not a bad thing) and so would audio forums (maybe not a good thing). On a related note it struck me that mp3 could be a guiding point. IMHO, mp3 can sound very good considering how much information is thrown away. If we already know what could be thrown away and sound good surely we could steps backwards and figure out what should be enhanced to sound great?

I have wondered too if sound without added artifacts is just bland? The same way I wonder if multi-channel using many 'good' quality channels is better than stereo using two 'high-end' channels. And, of course, the studio engineers who make all our music largely don't prescribe to the things audiophiles think important on the playback side. But the thing that irks most is feedback deniers who cannot explain why it is bad - only that it is. Or if they do explain why it is in a very hand wavy and not all rigorous way. Why is adding the least amount of artifacts to the signal a bad thing?

Non-professional audio is a place where people can make products without a solid technical background and proclaim it good because it sounds good to them. And they mostly have their own theories about things and if people agree and buy into the theories and then buy the products that is fine. As someone with a technical background I do cringe at some of the theories and explanations. Frankly, they can't all be right - vinyl vs digital, solid state vs tubes, box speakers vs panels, hi efficiency etc etc so I'm of the mind that if there isn't a single true way yet all paths have proponents there must be NO true way and none of it really matters. As long as you enjoy what you are hearing.

 

Yep, posted on June 14, 2024 at 07:07:54
E-Stat
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 that's the one. Do continue with what he says...

"That's the problem with THD, it just does not show what we need to know."

I learned that lesson in the 70s as a teenager.

And yet, SINAD is the sole metric by which ASR judges gear with its color coded chart - "higher better".


 

So are you an absolutist?, posted on June 14, 2024 at 11:41:34
Chris from Lafayette
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 No negative feedback at all for you? Or do you like a bit more distortion and noise in your listening?

Correct me if I'm wrong, but doesn't SINAD include more than just the THD component?

 

Just a music lover, posted on June 14, 2024 at 12:37:24
E-Stat
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 No negative feedback at all for you? Or do you like a bit more distortion and noise in your listening?

Some works fine to stabilize the circuit. Noise has nothing to do with it.

Yes, SINAD is noise+THD. Key being (useless) THD.

Maybe you're like Feanor and listen by looking at graphs. It that works for you, fine. :)

 

SINAD denier, stop the steal!, posted on June 14, 2024 at 12:46:29
13th Duke of Wymbourne
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 :)

 

Too funny!, posted on June 14, 2024 at 13:49:45
E-Stat
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 I guess simplistic metrics work for simplistic folks.


 

Bum rap alert!, posted on June 14, 2024 at 14:36:31
Chris from Lafayette
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 Feanor himself will tell you that I'm not like him an any significant way. So do you totally ignore graphs? If so, I think that kind of isolates you to your own little corner of the audio universe, along with a few other true believers. ;-)

And BTW, which is it? Negative feedback is OK, or noise and distortion are OK? Maybe a little of both for you? LIKE FOR MOST OF US? Remember, I listen to most Dolby Atmos recordings in LOSSY 24/48. ;-)

 

Too funny is right!, posted on June 14, 2024 at 14:40:08
Chris from Lafayette
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 Denialism of measurements and graphs will only get you so far! In fact, it could even be revealing of a. . . uh. . . simplistic mind set. ;-)

 

RE: Bum rap alert!, posted on June 14, 2024 at 14:50:20
E-Stat
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 Feanor himself will tell you that I'm not like him an any significant way.

Ok, so your shared enthusiasm for the value of SINAD is not significant.

So do you totally ignore graphs?

Only the ones that don't correlate to what we hear.

I do, however, use measured graphs to fine tune speaker placement and EQ for the HT. Here's upstairs which took some work along with a small forest of bass traps to achieve.



Negative feedback is OK, or noise and distortion are OK?

Why not quote something I posted and frame a question based upon it?

 

RE: Bum rap alert!, posted on June 14, 2024 at 15:11:59
Chris from Lafayette
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 "Ok, so your shared enthusiasm for the value of SINAD is not significant."
Why not quote something I posted and frame a question based upon it?

[I] ignore the [graphs] that don't correlate to what we I hear.
There! Fixed it for you, Mr. Self-Appointed Golden Ears.

 

RE: Bum rap alert!, posted on June 14, 2024 at 15:26:06
E-Stat
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 Why not quote something I posted and frame a question based upon it?

Question unnecessary.

Calls to mind this. Like Feanor, you're also not in the Geddes camp where correlation is the objective.

 

That's a non sequitur - yet another bum rap, posted on June 15, 2024 at 00:47:23
Chris from Lafayette
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 "Calls to mind"? Not to most intelligent people.

Sometimes, the correlation exists, but you simply deny that it does.

 

RE: I agree that huge amounts of negative feedback are generally considered. . . . . . , posted on June 17, 2024 at 02:25:38
morricab
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 Please look at the two papers he published on the subject at this link

http://www.gedlee.com/Papers/papers.aspx

The first is Auditory Perception of Non-Linear Distortion- Theory
The 2nd is Auditory Perception of Non-linear Distortion
There is also a slide deck that summarizes the two papers.

 

RE: So are you an absolutist?, posted on June 17, 2024 at 02:44:19
morricab
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 I am pretty much an absolutist...none of my gear has negative feedback other than degenerative feedback (like a cathode follower would use...even then I am not sure I have any cathode follower circuits in my gear...maybe my phonostage...)

The problem with only using a little bit of feedback is that you still have relatively high distortion but you have created a whole bunch of high order distortion, which remains unmasked and is likely audible.

Empirically though I have found that amps with a little bit of feedback often still sound more dynamic and less "gray" tonally than those that use massive amounts.

As Geddes and others point out, you can tolerate a fairly high amount of low order (meaning primarily 2nd and 3rd order...although Cheever allows for more at higher SPL because of the ears own distortion generation acting as a mask) due to masking. In fact, if the harmonics are effectively masked, it sounds to the listener as if there is NO distortion at all.

Cheever posits that as long as the distortion components are falling below the ears own distortion pattern and intensity that the component will sound pure and undistorted...even if it has measurably high distortion compared to other components that don't sound as pure. The pattern has to match (and at a given SPL) or remain below the ears own harmonic distortion generation.

As the ear makes essentially nothing above 9th harmonic...even at very high SPL (at normal listening levels it makes nothing really above 5th harmonic), ANY distortion harmonics higher than that will be audible even at exceedingly low levels.

As to why high feedback amps can sound "dead", "gray" and lacking in perceived dyanmics, especially on high sensitivity speakers where all is revealed, I think it has a lot to do with the "noise" floor. Crowhurst demonstrated in the 1960s that high feedback makes a lot of distortion produts...essentially an infinite number with a complex music signal. These are mostly at every low levels and essentially generates a signal correlated "noise" floor. True noise is not correlated with the music signal and as such it is possible to hear below that noise floor which helps with space, dynamics and low level detail. A correlated noise floor acts as a wall that one cannot hear below and as its modulating with level, it probably has very detrimental effects on the perception of the music. This might be why a minimal amount of feedback is not so bad as it would not create a very strong effect on this signal correlated noise floor.

High feedback also means that a lot of the back EMF from the speaker will find it's way back into the signal path, as some of it is injected back to the input stage (for amps with global feedback). That signal of course looks nothing like what went into the speaker and besides it is signal that doesn't align with what is currently passing through the amp.

Finally, Nelson Pass also weighed in on feedback (although his conclusion was a bit wishy washy). You can read that here:

https://www.passlabs.com/technical_article/audio-distortion-and-feedback/

 

RE: That's a non sequitur - yet another bum rap, posted on June 17, 2024 at 04:10:11
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 Geddes papers show a correlation does not exist.

 

RE: Too funny is right!, posted on June 17, 2024 at 04:11:06
morricab
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 Belief in simple interpretation of measurements will only get you so far.

 

Yes - I agree with that!, posted on June 17, 2024 at 10:36:05
Chris from Lafayette
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 But, in general, I believe that there IS a correlation between the sound and most measurements.

 

But if that's true, then why does he say what he did in the interview. . . , posted on June 17, 2024 at 10:39:08
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 . . . I quoted?

 

Thanks for the link to the Nelson Pass article, posted on June 17, 2024 at 10:58:32
Chris from Lafayette
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 You call his conclusion "wishy washy" but I would characterize it as less dogmatic.

You know, this whole discussion started when a few posters seemed to get triggered when Amir and Audio Science Review were brought up (not by me I might add!). As I've said all along, people have the right to their beliefs and perceptions - even though these perceptions may (and do!) change from day to day (as Geddes pointed out!).

 

Absolutely!, posted on June 17, 2024 at 16:38:21
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 from the Geddes interview:

"That's the problem with THD, it just does not show what we need to know."

I learned that lesson as a teenager.

I'm convinced Chris didn't follow and thus doesn't understand my "calls to mind this" embedded link where another inmate asks why he makes snide and scornful conclusions. Seems he rarely follows embedded links I provide and later asks question answered by them.

His reply is all the more ironic. ;)

 

RE: Thanks for the link to the Nelson Pass article, posted on June 18, 2024 at 01:05:58
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 People can believe what they want but the listening data strongly suggests that there are preferences that probably don't align with some people's belief. What is clear, is that THD and IMD don't correlate well with those preferences.

 

RE: But if that's true, then why does he say what he did in the interview. . . , posted on June 18, 2024 at 01:11:06
morricab
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 If you bothered to read the papers, he explains what he is on about and that he developed a metric to process distortion in a more meaningful way than THD and IMD. His metric takes the THD and IMD data and establishes a much better correlation with what the listeners reported than just plotting that versus THD or IMD.

So, what he said in the interview doesn't contradict the papers.

 

RE: Yes - I agree with that!, posted on June 18, 2024 at 01:28:01
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 Believe what you want. Unless the data is processed with an algorithm like the Gedlee metric or what Cheever came up with, you will not find a correlation between what people like and measurements. This was known as far back as the 1930s and 40s, because D.E.L Shorter from the BBC was trying to find such an equation to correlate the listening impressions with the measurements.

Raw THD and IMD numbers will not give you a good agreement with listening. Even looking at a raw FFT will not tell you too much. IMD also plays a big role but not the amount...the composition and that is very complex.

 

Yeah - except that THD is only one measurement among many, and. . . , posted on June 18, 2024 at 11:03:38
Chris from Lafayette
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 . . . you act as if I'm totally pushing THD as the be all and end all - which I NEVER have done. Check this thread. I just say that, in my experience, measurements (in general - not just THD) DO usually correlate with listening experience. Even YOU have admitted that when you say you use frequency response measurements to improve the bass response in your room.

 

What correlation are you talking about?, posted on June 18, 2024 at 11:06:55
Chris from Lafayette
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 I brought up the question of measurements in general, and you're trying to confine what I said to THD only.

 

Taken to its logical conclusion, your point would mean. . . , posted on June 18, 2024 at 11:14:47
Chris from Lafayette
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 . . . that equipment can have as much distortion as possible, and you would still claim there's no correlation? I think one appeal vinyl has for some listeners is that vinyl distortion is euphonic - and they find that pleasing. Euphonic does not equal accurate.

Where do you draw the line? How much distortion is acceptable. Is it anything goes? I doubt that many listeners would agree you in that case.

 

Just an utterly useless one! -nt, posted on June 18, 2024 at 11:25:34
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As previously observed, posted on June 18, 2024 at 15:35:02
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 he doesn't bother following links to actually understand what's being discussed.

I found the listening correlation data comparing THD, IMD and Gm compelling. You might as well flip a coin with the first. And really enjoy the selection chosen!



 

RE: Yes - I agree with that!, posted on June 18, 2024 at 18:51:20
13th Duke of Wymbourne
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 There is a program that allows you to add specific amounts of distortion to an audio file and then you can listen, if so inclined. I dabbled and found I could not distinguish what I thought were high levels of harmonics so I went back to just enjoying music :) And, as I've noted a few times recently, I have become primarily a vinyl listener in the past 2-3 years and LP reply is rife with non-idealities (that puts some of arguments about digital artifacts to shame) but it sounds really nice (because of vs. in spite of?)
Measurements in high-end audio are a moveable feast - a designer can use them if they show the product in a good light or declare them fake if they don't. I have the 'comfort' in my design day-job of having specs so I know when I am done. My head would like to solve all objective-subjective related discrepancies but my heart likes to think there are unsolved mysteries.

One final point, measurements - whether you think them valid or not - are usually taken with calibrated equipment. Audiophiles' opinions are never calibrated :)

 

Bum rap again!, posted on June 19, 2024 at 11:23:34
Chris from Lafayette
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 You're trying to pretend that all I care about is THD. Once again, not true.

 

Your claim is completely incompatible with his statement, posted on June 19, 2024 at 11:34:34
Chris from Lafayette
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 I'll quote the relevant part once again:
I have also never believed that all that matters is "how it sounds," because this is such an unstable and personal opinion. Sound quality opinions can and will differ from person to person, system to system and most importantly even within the same person on different days (as I said before, I have personally witnessed this in well regarded "reviewers"). Personal preferences have such a low stability as to be an almost completely pointless thing to stake a claim to.
That does not sound to me like he takes "what listeners reported" very seriously, metric or no metric. Contrary to your assertion, what he said in the interview DOES contradict your summary of the paper(s). How recent was his paper? Maybe he changed his mind over time.

 

Your challenge is, posted on June 19, 2024 at 16:38:42
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 you don't pay attention. You don't follow links. You don't follow observations. You don't even read the manuals for your gear.

Let's review what my last post observed of your behavior:

"As previously observed, he doesn't bother following links to actually understand what's being discussed."

It is clear from other questions you've made that you didn't download and read the two references found a day earlier here.

Hint: blue text in my posts signals a hyperlink. Click Chris, click!

I'm convinced this will be the very first time you've seen the referenced Powerpoint slides like this:









 

RE: Your claim is completely incompatible with his statement, posted on June 20, 2024 at 03:08:42
morricab
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 Read the papers and slide presentation and answer the questions for yourself.

He is talking about an individual response. Taken in aggregate you will build a statistical preference for most listeners (assuming you have a good correlation to the measured data) for particular types of distortion vs. other types.

Geddes papers (if you don't read them then we have nothing more to discuss) indicate that THD and IMD had no correlation (even a slightly negative slope) to the distorted sounds they were subjecting listeners to. When he applied his metric, which takes into account some kind of weighting for harmonic content, he got a much stronger and positive correlation between preference and his metric.

 

RE: Yes - I agree with that!, posted on June 20, 2024 at 03:48:43
morricab
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 Very interesting software. Keith Howard made something simpler many years ago and I tried and found I could clearly hear differences between different distortion patterns.


What would be really interesting would be to simulate existing amp profiles and see if one can hear the difference and then if one has access to those amplifiers, see if there is a similar response with the real thing rather than a simulation. My guess is that there are other things the software doesn't account for, like back EMF of a speaker for example.

 

RE: Your challenge is, posted on June 20, 2024 at 03:53:47
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 Indeed. Cheever also came up with a metric that included SPL because the ear/brain masking extent (i.e. what harmonics and how much) changes with SPL.

This is why low SPL is more critical than high SPL because masking is less effective, particularly for high order harmonics even at very low levels. They also tend to be about the same regardless of amp output in a feedback type amplifier. It is also probably why low level resolution and soundstage/imaging are most affected by the negative effects of high order distortion and negative feedback.

 

RE: Taken to its logical conclusion, your point would mean. . . , posted on June 20, 2024 at 04:03:07
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 There is audible and then there is perceived as distorted.

Look at some of the levels of distortion applied in the Geddes paper. Some are very low and some are pretty darn high.

 

RE: Yeah - except that THD is only one measurement among many, and. . . , posted on June 20, 2024 at 04:06:54
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 What do frequency response measurements (linear distortion) have to do with THD (non-linear distortion)? What studies have you done to demonstrate that you can correlate your preferences with THD level? I guess the answer there would be none, right? It's just your gut feeling that you would prefer a low distortion amplifier over a higher distortion one.

 

I think GedLee did his best work in Rush, posted on June 20, 2024 at 12:02:45
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 I scanned through the two AES papers and the conclusion is convincing that THD and IMD doesn't match the subjective scoring of their test group whereas their Gm metric (bad choice of symbol as Gm means something else to a lot of people) does correlate much better. There is much to pick over - in the first part they don't quantify masking. Yes it is a psychoacoustic thing but how much effect does it have and why choose a cos^2 weighting factor? I also question one of their precepts that distortion will be more apparent at low signal levels than high signal levels - that needs some explaining as distortion grows quicker than the signal level that causes it (i.e. if a signal increases by 1dB any second harmonic will grow by 2db, third harmonic by 3dB etc).

We aren't told what the 21 transfer functions are nor their correspondance to trial number. We do know one/some/many have severe discontinuities - are those really relevant for high-end audio? And they remove 6 of those transfer functions at the end because they don't fit the scatter plot so well (at least they were open enough to admit this as data manipulation is often a big problem in academic papers).

But, the big unanswered question is whether a low distortion system is somehow worse? We don't know because they don't detail the transfer functions! We can probably conclude that many non-linearities are not that audible, or audible at all, but we can't conclude that low distortion devices are somehow subjectively inferior. So it is a bit of a shield for audiophiles to stand behind and an excuse for high-end audio designers to not work too hard but not the full story.

 

RE: I think GedLee did his best work in Rush, posted on June 21, 2024 at 05:45:55
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 Indeed! Rush rules!

Cheever added an SPL factor into his model because there is also a change in the ear's own generated harmonics. It also then would depend on the sensitivity of the speaker and how much distortion/power at a given SPL...


So, a high sensitivity speaker that only needs mW to a couple of watts will be an easy, low harmonic dominated (which are basically masked) distortion pattern that will sound clean.

Once you get beyond a certain SPL it will really depend on how rapidly the devices distortion, particularly the high order harmonic distorion rises and how that still compares to the ear/brain masking...complicated but can go a long way to explaining a lot of the subjective varaiabilty observed.

"But, the big unanswered question is whether a low distortion system is somehow worse? We don't know because they don't detail the transfer functions! "

It is not low distortion per se, it is the fact that there are high order harmonics without lower order harmonics to provide masking. The audibility seems to be down to very low levels. Achieving this with negative feedback has it's issues with regard to artificial noise floor (read Crowhurst and Pass white paper) and IMD that gets generated. Just seeing absent harmonics in a static test does at all tell the whole story.

 

I'm sorry for the two of you, but the critical observation Geddes made. . . , posted on June 23, 2024 at 17:02:12
Chris from Lafayette
Audiophile

Posts: 27205
Location: SF Bay Area
Joined: February 17, 2004
Contributor
  Since: February 6, 2012
 . . . was that even INDIVIDUAL subjective perceptions of sound can change from day to day or even hour to hour FOR THE SAME PERSON perceiving the same sound.

How are you going to account for that - and then "quantify" it? It seems to me that the only option you have is to do so in a faux scientific way - by arbitrarily assigning "values" to reactions which cannot by their nature be quantified.

The two of you try to denigrate listeners who set some store by measurements (and not just THD!), and yet you then turn around and quote these "scientific" study measurements which are IMHO pretty dubious.

 

No, YOUR challenge is not to be star struck by. . . , posted on June 23, 2024 at 17:19:58
Chris from Lafayette
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Posts: 27205
Location: SF Bay Area
Joined: February 17, 2004
Contributor
  Since: February 6, 2012
 . . . studies which have only the most peripheral relationship to to my posts. Let me remind you of what the main point of my posts was: that measurements (and NOT just THD!) can help us in describing the sound of a given component. You admitted that that was true yourself. But then you turned around and started in with a bunch of bunk you somehow divined from my previous posts.

So I don't follow observations? I think that's MORE true of you. If distortion measurements are so useless, why do almost ALL audio manufacturers provide them? Are they trying to deceive customers? Seems to me that you and Morricab are out in the cold with you own contentions on this point. (And, BTW, I'm NOT disputing that masking is a thing. After all, I prefer to listen to Dolby Atmos these days - which I listen to mostly via Apple Music's LOSSY streaming! Talk about masking! LOL!)

And just because you posted a picture of your listening environment which CLEARLY showed your speakers placed perpendicularly to each other doesn't make it incumbent on me to follow YOUR observations - or anyone else's "observations" for that matter.

 

Too funny!, posted on June 23, 2024 at 18:05:34
E-Stat
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Posts: 38789
Joined: May 12, 2000
Contributor
  Since: April 5, 2002
 which CLEARLY showed your speakers placed perpendicularly to each other.

How they radiate into the room, however, is symmetric. Per the manual, each is aimed 30 degrees to listening area.

I can recommend a good oculist for you. ;)

 

RE: I'm sorry for the two of you, but the critical observation Geddes made. . . , posted on June 28, 2024 at 02:58:14
morricab
Distributor or Rep

Posts: 9229
Location: switzerland
Joined: April 1, 2005
 You clearly haven't heard of statistics...think about it or read about it and it will perhaps come to you eventually how you can get some useful data out of individual preferences.

As to the industry, they provide the measurements they kind of have to, not the ones that would be useful (if fitted with the proper model). They publish THD and maybe IMD...almost no one provides a detailed FFT and model fitting. Aries Cerat provides the level of H2 and H3 at a given power...but that is an exception rather than the rule and the assumption they make is that there is an exponential decay in the harmonics with increasing harmonic order.

 

RE: Picked Up my 1st DSD DAC. Verry Interesting. , posted on June 28, 2024 at 04:06:11
Leo loves music
Audiophile

Posts: 208
Joined: October 14, 2021
 Same thing happened to stereophile. A reviewer often provides misleading information.

 

RE: Picked Up my 1st DSD DAC. Verry Interesting. , posted on June 28, 2024 at 04:20:07
Leo loves music
Audiophile

Posts: 208
Joined: October 14, 2021
 Do they still use transformers in MK2?

 

RE: I'm not the one divorced from reality., posted on June 28, 2024 at 04:58:35
Leo loves music
Audiophile

Posts: 208
Joined: October 14, 2021
 "The engineers at Chord and PS Audio know FAR more about DAC design than most people, including the so called audio critics/reviewers. Arrogance is no substitute for actual knowledge. Reading a flawed review from ASR does not suddenly make you smarter than the design engineers."

Sure they know how to cheat your ears and make their stuff more "musical". Some people simply like distortion and soft sound.

 

Illogical reasoning. I'll stick with engineering. , posted on June 28, 2024 at 05:02:43
Freo-1
Audiophile

Posts: 1369
Location: Florida
Joined: June 14, 2008
 NT
" Don't look back. Something may be gaining on you"

Satchel Paige

 

RE: Illogical reasoning. I'll stick with engineering. , posted on June 28, 2024 at 05:30:09
Leo loves music
Audiophile

Posts: 208
Joined: October 14, 2021
 When they came out the DirectStream Memory Player, they said it is the best and the ultimate player you ever need. So what was the sales result?

 

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