Chord Huei Phono Preamp Review

[artburda]

I am not sure what you are trying to say. Observation is step one in the science process. Anyway we are not discussing if measurements are science. Are part of science but not science by itself. We are talking about the phono preamplifier and I just wanted to share that my observations from having the unit for about 7 months and the fact that are different from the conclusions made. That’s all. Overall I found the preamp very well made, without any auditable noise/distortion, good connectivity for long cable runs and great flexibility in terms of settings & adjustments

So, you bought an expensive device with sub-par performance? Is this the first time that you got ripped off by a company?

 

[Deleted member 31750]

That depends on the circumstances, listening level, recording, used transducers its 'surroundings', the experience of the listener.
Again there is no 'single' number here.

Many have tried to explain this to you in many different ways over the last 160 posts.

A SINAD of 50 dominated by noise is not the same as a SINAD dominated by distortion. A SINAD with distortion products only being 2nd harm can be less 'detrimental' than if it were 3rd, 4th or 5th dominated.

SINAD only says something about the total 'error signal' S/N ratio + all generated harmonics opposite a specific 1kHz stimulus. It is just one measurement 'number' from a set reference point.
A SINAD of 50 may well sound great yet a SINAD of 70 may sound poor. It all depends on what the 'error' is made of and the circumstances.
Harmonics and noise spectrum are also important which you cannot see from a 'number'. You need the plots, understand the levels and know what all the plots tell you.

You see... there is no single 'number' catching all aspects. You demand to be told a number but you ain't gettin' it because there is none in this particular case.
You demand to know why Amir mentioned it was 'broken'. That may not be your opinion but Amir does not have to retract his opinion based on his measurements and experience just because an owner is happy.
Amir stated WHY he came to his conclusion. What's the mystery ? What's with the fixation of SINAD ? What's up with demanding a single number just as if that single number would mean the difference between good and bad. That's not how this works.

My aim is not to challenge Amir’s measurements and/or “make him” amend his conclusion because I am too ignorant to do that. All I want is to understand why the equipment is considered broken or problematic in a way that has to be recalled and redesigned. You are right that many have tried but who succeeded to explain simply why and when an equipment is considered broken. You rightly so say that is very complicated and depends on many factors. Should also the conclusion those that into account before such bold statement? I don’t know but still I don’t understand why is considered broken instead of “not as good as A”. Just like his assumption on the rumble filter. He did the test, the result show not effect and he concluded that the equipment’s rumble filter is doing nothing. Without even considering that his test might be measuring the wrong thing only to be reminded by a member that this is not a filter but a mono function below a certain frequency. Let me ask you then that. Do you agree with Amir that this is a broken design that should be recalled and redesigned?

 

[Deleted member 31750]

So, you bought an expensive device with sub-par performance? Is this the first time that you got ripped off by a company?

I don’t really understand what this has to do with the discussion.we are discussing the nature of measurements and the interpretation to understand when a phono stage is problematic and what the measurements tell us. Nothing to do with a purchase of any equipment. Do you know at what level SINAD and SNR levels are problematic and the designer needs to do something about it?

 

[artburda]

I don’t really understand what this has to do with the discussion.

Would we all be having this discussion if Amir's measurements and recommendation reflected more closely your subjective opinion about the device in question?

 

[Deleted member 31750]

Would we all be having this discussion if Amir's measurements reflected more closely your subjective opinion about the device in question?

I would ask anything I don’t understand. All I know is that I have many questions and very few, if any answers. My questions are not for the huei specifically. It’s all about understanding the nature of a measurement and when a number matters. This is across the board. For example a phono A with SINAD 90 and a phono B with SINAD 85. A is better than B but is a difference that will give a tangible benefit? Does the designer need to spend time, money effort to move from 85 to 90? What these numbers mean? When is “bad SINAD” and why? You see, my questions have nothing to do with the Chord Huei. Also I never expressed a subjective opinion.

 

[Sir Sanders Zingmore]

I'm sure there's a word for this…. let me think

 

[Harmonie]

While we are on page 15, I lost the follow-up of this thread since page 7. Just saying ...

 

[solderdude]

Do you agree with Amir that this is a broken design that should be recalled and redesigned?

recalled is something different then 'not sold any more' (pulled from the market, which is what Amir basically said). You have to recall something when it for instance is a safety hazard (fire, shock etc). Two very different things.

Redesigned....perhaps. There certainly are things I would try to improve were it my design.

I am not as stringent as Amir about certain things though. You can call me optimistically lenient because of my own testing of my audibility levels.
It is his review, his measurements, his findings and his conclusion. It is basically Amir's website.

 

[Deleted member 31750]

recalled is something different then 'not sold any more' (pulled from the market, which is what Amir basically said). You have to recall something when it for instance is a safety hazard (fire, shock etc). Two very different things.

Redesigned....perhaps. There certainly are things I would try to improve were it my design.

I am not as stringent as Amir about certain things though. You can call me optimistically lenient because of my own testing of my audibility levels.
It is his review, his measurements, his findings and his conclusion. It is basically Amir's website.

Not sold anymore. Do you endorse this conclusion?

 

[Sir Sanders Zingmore]

I'm sure there's a word for this…. let me think

Trolling, that’s the word

 

[Deleted member 31750]

Trolling, that’s the word

Not at all. I am not trolling. Read the discussion. I have genuine questions, have been always polite and respectful. What makes you think I am trolling and where you’ve seen a text from me being trolling something or someone?

 

[abdo123]

am i the only one who thinks the question 'at what point noise becomes a problem' completely ridiculous?

noise is noise, it is a problem when we can hear it. we're not inventing the wheel here.

 

[solderdude]

Do you endorse this conclusion?

I think Chord can definitely do better.

 

[Deleted member 31750]

I think Chord can definitely do better.

The enemy of good is better. Right? But the question was if you endorse the conclusion that this product is so bad that needs to be removed from the market and redesigned? What do you think?

 

[Deleted member 31750]

am i the only one who thinks the question 'at what point noise becomes a problem' completely ridiculous?

noise is noise, it is a problem when we can hear it. we're not inventing the wheel here.

The question is not at what point noise become a problem. The question is at what point the SINAD and SNR indicate that there is a problem that needs to be addressed. No

 

[solderdude]

I just posted what I think.. I think Chord can (and should) do better.
They focused too much on versatility with a weird interface... just to be different and sell it at higher cost.

 

[amirm]

I don’t and I never claimed that I know

But you have taken specific action there by opting for safest path even though there may be zero value to you. This is the answer we have given you for audio yet you refuse to accept it.

 

[solderdude]

The question is not at what point noise become a problem. The question is at what point the SINAD and SNR indicate that there is a problem that needs to be addressed. No

We've answered that already. Noise is ONLY a problem when it becomes audible and ruins the sound quality.
As explained a zillion times: You do not seem to get the SINAD and S/N ratio issues involved with phone pre's at all.
It was explained a few times.

 

[abdo123]

The question is at what point the SINAD and SNR indicate that there is a problem that needs to be addressed. No

pick up your favorite pair of headphones, raise the volume to the levels you normally listen at and listen to the noise.

'high gain' setting on the chord should be fairly audible when nothing is played.

 

[amirm]

The question is not at what point noise become a problem. The question is at what point the SINAD and SNR indicate that there is a problem that needs to be addressed. No

OK, at the computer now so can give you a longer answer.

SNR and SINAD are engineering measurements that are automated and can be instantly made. To this end, when a company doesn't bother to make such, or produces equipment with poor ratings in them, they deserve criticism unless they answer question: what good did the extra noise and distortion do for the listener? In this forum, the general answer is that it hasn't done any good.

Both noise and SINAD can be bookmarked at either end easily. Get noise and distortion below -115 dB and you are guaranteed for it be inaudible for all people, all situations, all content, etc. At the other extreme, drag them down to say -20 dB, and everyone can hear the impairment.

What exists in between is a giant gray area. Assessing audibility requires either controlled listening tests, or psychoacoustic analysis. The latter is what I use often in commenting on whether impairments I find are audible. A jitter component at -130 dB is declared as inaudible. A jitter component -90 dB -- above threshold of hearing -- is also considered inaudible if it is close to our main tone (masking). So mere violation of above range doesn't make them audible. Spectrum matters and such is shown in my measurements (e.g. FFT).

You could complain that life is unfair if you can't just glance at the SNR and SINAD values and determine if there is an audibility problem. My answer is sure, it is unfair. In an ideal world, a Doctor's statoscope would instantly tell you that if you -- heaven forbid -- have lung cancer. But it doesn't yet your doctor always uses it as a first level diagnostic. He uses that plus a world of experience to know if there is cause for concern or not.

I asked my doctor once why he couldn't give me definitive answer on a question I had. He said, "you engineers are used to black and white answers. Our world is nothing but gray. We get some data and make educated guesses but at the end, it is not definitive." Our dog had a cist removed and they prescribed antibiotics. They said he doesn't need it but dogs being dogs, they may get the wound exposed to the outdoors and get an infection. So some prophylactic was in order.

Same here. I can't in the couple of hours I have conduct full controlled listening tests, or psychoacoustic analysis. I measure common metrics that tell me, as an experienced reviewer and engineer, whether performance was left on the table that could become audible. I express that opinion in the review. That word is key: I write both measurements and reviews. What makes the post a review is my experience and overall assessment of what I just observed. You could ignore that if you have higher level of knowledge and insight than I do. Otherwise, I suggest not second guessing that any more than you do that with your doctor when you have no medical knowledge or advice of another doctor.

In this case there is special dynamics: CHORD as a brand is known for over-engineering and impeccable attention to smallest impairments. Dave actually goes tens of dBs beyond threshold of hearing because well, he thinks there is audible problem there (without any verification per above). This halo reputation is going to lead people to buy this phono stage thinking they are getting the same, over-engineered products. Well, they are getting the exact opposite. What they receive is one of the worst measuring and engineered phono stages I have seen or measured.

Because of the above, Chord is better off going back and cleaning up the design. It will then better match their brand and reputation they have created.

Remember also that other choices of products exist without these problems at much lower cost. To that end, as I tried to explain with that washing hand analogy, you can buy them and sleep easy that you are not injecting a ton of distortion and noise that might be audible into your system. That is the value we bring here. To the extent you want to be dismissive of this service, then we have nothing else for you.