CHORD M-Scaler Review (Upsampler)

[John Atkinson]

From the M scaler Stereophile Review by John Atkinson, Feb 25, 2020 in the Digital filters and upsampling section:

"In the promotional literature for the M Scaler, Chord writes, "The Hugo M Scaler . . . takes the digital file and repairs it, adding back the information lost between the samples, then it sends the repaired file to the DAC. . . . With 705,600 samples per second, a huge amount of important information that was lost when creating the 44.1 digital file is now recovered. The more samples, the closer you get to the original analog signal. . . . The Hugo M Scaler in essence places 15 additional new musical samples in between each original musical sample, resulting in an astounding improvement in the recreation of the original music signal."

Note that I was quoting this text, not agreeing with it. In my review I followed the quoted text with this:
"The measurements I performed to accompany our reviews of the dCS 972 and Purcell definitively showed that upsampling doesn't add information above the Nyquist frequency—22.05kHz with CD data—of the lower sample rate. So what is the M Scaler doing?

"In one of the first articles I wrote for Stereophile, 'Zen & The Art of D/A Conversion,' which was published in September 1986, I discussed how the recovered analog signal is not directly described by the levels of the digital samples. Instead, the interaction between those samples and the impulse response of a digital low-pass reconstruction filter recreates the analog waveform—not just at the sampling intervals but between them. By processing the incoming data with a low-pass filter featuring an extremely long impulse response, the M Scaler makes it possible for the accompanying DAC to more accurately reconstruct the analog signal. In effect, it replaces the DAC's digital filter with its own, as the DAC's filter is now operating at the higher sample rate, and its cutoff is one or more octaves above the original data's Nyquist frequency."

John Atkinson
Technical Editor, Stereophile

 

[John Atkinson]

Hi,
The lead in and the tail of the impulse response is not like a low pass filter i have seen. Is the high values at the start of the impulse and at the end, due to noise shaping ?

The test signal is a series of single samples at 0dBFS interspersed with digital black. The Chord reconstruction filter's impulse response is sufficiently long that in this graph it overlaps both the end of the preceding impulse and the beginning of the next.

John Atkinson
Technical Editor, Stereophile

 

[Jomungur]

Have you received your D90SE and try some listening tests? I was curious after reading your post so I want to see your follow-up .

Yes, I have. So far on electrostatic headphones. I still need to test with my loudspeakers.

All subjective. I'll write more later but let's just say my only consolation is the Topping 90DSE wasn't on the market when I purchased the DAVE...

 

[Jimi Floyd]

Note that I was quoting this text, not agreeing with it.

I am perfectly aware of this and hope my post was very clear about it. Best regards.

 

[Jomungur]

I didn’t think they were unreasonable questions, that would help me understand better.

40 odd pages on a box that was doomed from the off…..that’s all I need to know. On to something more interesting.

I wouldn't say it was doomed experiment from the start, even if Amir was skeptical. If the M Scaler did something significant, the reconstructed signal should have been noticeably different than what it turned out to be. It turned out to be not much different than what the signal would be without it, and the differences observed were inaudible at best.

We have no ideal to compare it against because you can't tell from Chord's own claims what it is supposed to be doing objectively. All we know is it is supposed to produce demonstrably "superior sound". If someone feels that what it adds to the sound is immeasurable, then, yes, any objective test would be doomed from the start. As I've said a few times in this thread, the whole reason I wanted to send it in for testing is I was having doubts as to whether it was doing anything. The objective measurements help me confirm my subjective doubts.

 

[Wunderphones]

I'm not sure if this was posted already, but I thought it was kind of interesting. Today YouTube was recommending that I watch this video, wherein an audio reviewer gave Rob Watts about a half hour of interview time to explain why those jitter numbers are no big deal:

Since I have no intention of buying an M-Scaler, I didn't watch the whole thing. But if there's one thing we can definitely say about Rob Watts, it's that he loves to talk about the devices he has engineered. So if you want the other side, it's definitely here.

 

[raif71]

Rob should really read up on Shannon information theory

 

[amirm]

Since I have no intention of buying an M-Scaler, I didn't watch the whole thing. But if there's one thing we can definitely say about Rob Watts, it's that he loves to talk about the devices he has engineered. So if you want the other side, it's definitely here.

It is not the other side. He says at the start he has not read the review.

 

[raif71]

It is not the other side. He says at the start he has not read the review.

Yes, he did say that he hasn't yet read the review during the interview but I hope the questions by Lachlan during the talk, he kept to speed about issues in the review to RW. Anyhow, I hope by now RW would have read the review. Cheers

 

[MacCali]

It is not the other side. He says at the start he has not read the review.

I totally agree, I do watch Lockland and he’s a nice reviewer. Not saying what he suggests is accurate since it is on the subjective side and can be naturally bias, he too is starting to get into measurements or being open to them.

The guy is seeking the truth, he owns an m scaler and it would be crushing to find out it’s that bad or harms the sound. Especially after he gave it a strong recommendation

I really don’t want to create a battle or feud with Rob watts but I really would like to know if he has any truth in his rebuttal. Clearly he can’t come out and say the product was a failure, and clearly I’m not sure who is more or most qualified to point out what is accurate or simply a cover explanation.

 

[amirm]

Yes, he did say that he hasn't yet the review during the interview but I hope the questions by Lachlan during the talk, he kept to speed about issues in the review to RW.

But he didn't. He said I didn't listen. I did listen. I also provided audio samples which he is welcome to listen to and say which is from his box! He also kept complaining that he didn't know how the graphs were generated, "what dac was used, etc." All he did in there was throw out a bunch of signal processing buzzwords which went over the head of the interviewer and everyone watching the video. Mission accomplished! How fast do you need to run from a bear? Faster than the guy with you!!!

If you are going to interview someone, you need to know what he knows so that you can challenge him if he says something that is not correct. When he says he has conducted hundreds of these listening tests, one should ask where they are documented. What was the protocol. When he says any psychoacoustic book backs what he says, then question is which book, which chapter and which section. Otherwise it is just an infomercial. Heck there is a bit in there where Rob is talking about least significant bit (LSB) and interviewer puts up a tag saying "MSB" (Most Significant Bit). 10 seconds later Rob states again that it was the Least Significant Bit!

How the heck does this industry counter independent, in-depth review by just letting a manufacturer talk? And folks line up to believe him. It is such a broken and corrupt industry. Interviewer is testing Chord products so no doubt is at mercy of company sending him such a box...

 

[amirm]

I really don’t want to create a battle or feud with Rob watts but I really would like to know if he has any truth in his rebuttal. Clearly he can’t come out and say the product was a failure, and clearly I’m not sure who is more or most qualified to point out what is accurate or simply a cover explanation.

There is no truth to what he says as far as audibility. Proof point of that is a controlled listening test which he doesn't have. Yet he keeps saying the difference is huge, audible, etc. Then just create a 10 minute video and let's see how huge and obvious it is. Let's throw out measurements. Just ears. Let's see the truth for heaven's sake.

Until then, his claims are beyond absurd. He wouldn't be able to publish a paper at AES on any of this.

There are two types of people who build useless products for the industry:

1. Those who claim all kinds of magical thing, like a cable, then slap a simple thing like that together and charge thousands.

2. There are those who put a ton of engineering, solving a problem that doesn't need more solving. Rob Watts falls in this category.

Both of these are bad for audiophiles and consumers in general. Audiophiles want to better the sound of their system. They deserve definitive answers, not hand waving.

The second group is especially dangerous since buyers just trust them based on work gone into the product.

 

[tmtomh]

These guys - Rob Watts, Danny Richie, Paul McGowan as far as I can tell - make an intentional practice of refusing to actually read Amir's reviews or watch his videos. The *result* of this practice is that, as @amirm notes above, they always miss things and get their facts wrong about what Amir did and did not test, how he did or did not test it, and whether or not he listened.

But the *motivation* for this practice, I believe, is that they are threatened by someone systematically evaluating their gear in a way that calls their technical/marketing claims into question - and I am convinced that they refuse to actually read/watch the original reviews because they don't want to "dignify" them or give the impression that they consider them in any way valid or on equal technical footing with themselves. It's a deeply arrogant and defensive move, and it makes them total hypocrites when they complain about objectivists not wanting to listen or being close-minded.

 

[GDK]

I am convinced that they refuse to actually ADMIT THAT THEY read/watch the original reviews…

FIFY

 

[raif71]

These guys - Rob Watts, Danny Richie, Paul McGowan as far as I can tell - make an intentional practice of refusing to actually read Amir's reviews or watch his videos. The *result* of this practice is that, as @amirm notes above, they always miss things and get their facts wrong about what Amir did and did not test, how he did or did not test it, and whether or not he listened.

But the *motivation* for this practice, I believe, is that they are threatened by someone systematically evaluating their gear in a way that calls their technical/marketing claims into question - and I am convinced that they refuse to actually read/watch the original reviews because they don't want to "dignify" them or give the impression that they consider them in any way valid or on equal technical footing with themselves. It's a deeply arrogant and defensive move, and it makes them total hypocrites when they complain about objectivists not wanting to listen or being close-minded.

I wouldn't go so far as to say they refuse to read or watch videos and gonna give them the benefit of the doubt. Eventually one way or another they will be exposed to whatever info here in ASR. To me there will be two sides of a coin and whatever is revealed here has truths and the other side will have some truths too (yes, some here may not the same view as I do that the other side has points ). If the the two sides can acknowledge that, then I believe progress can be made but if either side think that they are both right, then we're gonna go back and forth and round and round. I hope this situation doesn't persist forever but then who am I to get what I want. Perhaps this is what needs to happen before any natural equilibrium is achieved or not.

 

[amirm]

To me there will be two sides of a coin and whatever is revealed here has truths and the other side will have some truths too (yes, some here may not the same view as I do that the other side has points ).

Why? If your hands are dirty, is there another truth that they are clean? I have tested 1,200 products. How often has the other side come into play? This is not a verbal argument of he said/she said. We are talking about measurements that are objective and repeatable.

 

[raif71]

Why? If your hands are dirty, is there another truth that they are clean? I have tested 1,200 products. How often has the other side come into play? This is not a verbal argument of he said/she said. We are talking about measurements that are objective and repeatable.

noted, @amirm

 

[AndrewC]

These guys - Rob Watts, Danny Richie, Paul McGowan as far as I can tell - make an intentional practice of refusing to actually read Amir's reviews or watch his videos.

I don't believe for one second that RW hasn't read Amir's review. He clearly has the time to read all sorts of inane posts on head-fi.org, yet hasn't read the most "controversial" review to date on his baby?? Nah, I don't buy it.

 

[amirm]

I don't believe for one second that RW hasn't read Amir's review. He clearly has the time to read all sorts of inane posts on head-fi.org, yet hasn't read the most "controversial" review to date on his baby?? Nah, I don't buy it.

I am with you. It is the attitude of "they are not important enough for me to even read what they have to say." But it will change.

 

[Snake Oil is life]

I am with you. It is the attitude of "they are not important enough for me to even read what they have to say." But it will change.

You need to have 1000+ burn-in hours on your cables to be worthy of reading for these people !