Review and Measurements of PS Audio PerfectWave DirectStream DAC

[escalibur]

”Value is not determined by those who set the price. Value is determined by those who choose to pay it.” -Simon Sinek

No comments.

 

[Julf]

Your English is perfect.

Thanks! I do have to admit I have an unfair advantage - not only is my wife American, but she teaches English Literature at college level.

 

[Ron Texas]

Since this forum is in English, my skills (or lack thereof) in other languages are not relevant.

There are other people who have trained as @amirm has. I remember a lot of discussion by those who had trained to detect artifacts in various sound compression schemes using these skills to do development of these codecs. Of course, they tested blind.

 

[Julf]

Since this forum is in English, my skills (or lack thereof) in other languages are not relevant.

But it is a global / worldwide forum, so better accept that it uses the currently most popular international language - bad English.

 

[HammerSandwich]

2. When there is plausible reason to believe, based on measurements, that the distortions could be audible, I set up controlled tests, with levels matched, transparent playback system, and instant switching between samples. I then perform the test blind to see if I can identify the degradations.

@amirm, perhaps you should explain this with a bit more detail. How are you blinded? How do you switch?

Apologies if I missed these details in an earlier post. For the record, I trust you to do this properly, but it's clearly a point of contention/confusion.

 

[Ron Texas]

But it is a global / worldwide forum, so better accept that it uses the currently most popular international language - bad English.

LOL, I hope I don't fall into the bad category. The problem isn't skills with English so much as not thinking before pressing the post button.

 

[Julf]

LOL, I hope I don't fall into the bad category.

It is not always bad to be bad. I do remember a colleague, let's call him Rupert, who was struggling in an international environment simply because he used language that was way too complicated, subtle and sophisticated. I would sometimes be asked (privately) after a meeting "I know Rupert spoke out about our proposal, but was he for or against?".

 

[audioBliss]

seems like an interesting experiment that is a complete failure. i don't understand -- how can one ship a product like this in good conscience? a negative result should be great motivation for continuing R&D, not shipping product.. the only situations i know of where something like this has happened was situations where either the engineer was too stubborn to believe his own measurements, or when the company was in "make it or break it" mode and just had to ship _something_.

The thing is that I don't think they actually know what they have shipped at all. They've slapped some stuff together and called it a day. I refuse to believe that any of these companies that ship these really expensive but poor products actually have a clue. They are not curious about their products, they don't care about their product or have any pride in what they are doing. They found a market where they could make money. I think it's that simple. I don't think they're actively trying to scam people. Hi-fi is just not very interesting to them. But money is.

 

[mi-fu]

It is not always bad to be bad. I do remember a colleague, let's call him Rupert, who was struggling in an international environment simply because he used language that was way too complicated, subtle and sophisticated. I would sometimes be asked (privately) after a meeting "I know Rupert spoke out about our proposal, but was he for or against?".

LOL... I'm sure it is not about English. When I deal with Englishmen, I always have the same puzzlement like your colleague.

 

[Ron Texas]

It is not always bad to be bad. I do remember a colleague, let's call him Rupert, who was struggling in an international environment simply because he used language that was way too complicated, subtle and sophisticated. I would sometimes be asked (privately) after a meeting "I know Rupert spoke out about our proposal, but was he for or against?".

Rupert should run for Congress.

 

[audimus]

There is an implicit assumption in relating measurement to hearing that is obfuscating a problem in reconciling the two camps.

Calling something a distortion or noise implies that it is necessarily something that sounds bad. But this assumption is not scientifically valid if one thinks about it objectively. A clipping or buzzing noise for example might sound bad. A harmonic that does not clash diatonically might not only not sound bad but some may perceive it as good because unless you know if it was from the original recording, you would be unable to distinguish it from the recording. This is typically dismissed as a subjective preference. But wanting to listen to exactly as the recording is also a subjective preference if you think about it.

Let us say we call the measured metric deviation (as in deviation from input). One might have as the goal to have minimum or zero deviation from the input. There is nothing inherently or by some natural law right about it. It is a personal preference. And if you find a deviation does it necessarily imply it sounds bad to others? Objectively, the answer must be no because it might satisfy another’s personal preference (for a warmer sound, brighter sound, punchier sound, causes less fatigue, etc).

The problem with the measurement metric is not only that that it is unable to state firmly what is audible but also unable to distinguish between audible deviations that cause one to observe bad effects - exaggerated tonal imbalances, hisses, clipping sounds, pops, loss of localization, etc from effects that is either a non-issue or for some positive - preferred tonal balance, etc.

As long as that situation exists, it is quite possible for the measurements and listening perceptions (even when done under perfectly controlled situations) to co-exist in conflict and not have a perfect correlation when you remove some of the outliers in measurement.

In other words, for all the sophistication of the measurement, it is still a blunt instrument for that finer distinction. Unless that part is solved, it will never be the final word in audio except for those that have an engineering preference for lack of deviation.

 

[amirm]

@amirm, perhaps you should explain this with a bit more detail. How are you blinded? How do you switch?

Apologies if I missed these details in an earlier post. For the record, I trust you to do this properly, but it's clearly a point of contention/confusion.

I randomly connect the inputs to an AB switch and then listen. Once I identify a difference, then I look up which is which. But I had no idea which setting was which (RCA or XLR). I repeat the test a few times this way, disconnecting the cable from the back to know which one is which (that input goes silent).

 

[SIY]

This subject practically requires its own thread . I posted a lot of the information you are after here: https://audiokarma.org/forums/index.php?threads/jolida-black-ice-fx-dac-azclub-audio-dac-off.883739/ see the fifth post down where I outline the event and format.

There is also a thread on Agon about it which is linked it the above thread as well. Happy to answer more questions as I can.

I wanted to attend, but was traveling. The stats you emailed were pretty inconclusive, which isn’t at all surprising. See you Wednesday?

 

[amirm]

Read this on PS Audio Forum:

I am so surprised. A $6,000 DAC and they could not afford to put in the Jensen transformers? Are they kidding? If you are going use a transformer in a high-end device, you need to use the best there is and Jensen is it. Who knows if the other even have proper measurements for their transformers.

Mind you, as I showed, even the Jensen has distortion but reading that they settled for even less, is just so surprising.

On top of that, they have this story of how the prototype led to creation of this product. But now we see that they used a different transformer than what impressed them?

 

[Ron Texas]

So much for a Stereophile's A+ rating. Perhaps the goal is to strategically lose some of the recording making it sound better with overly analytical speakers.

 

[mkawa]

how many of these things are they realistically going to sell a year? 6k for boutique means bom plus labor at that qty has to be 1.5k. (3k to the retailer, 6k from the retailer to customer). it seems like they are not using an OTS SBC platform which, imo is a huge mistake, but that is likely pushing their SBC price up in the hundreds range already. add all the stuffed custom boards in at > 100$ per at this volume and you hit 1.5k easily.

further, if they sell even fewer of these (i don't know.. 10/yr?), double the cost of BOM and your labor becomes the cost of a software engineer assembling a chassis.

 

[LTig]

The thing is that I don't think they actually know what they have shipped at all. They've slapped some stuff together and called it a day. I refuse to believe that any of these companies that ship these really expensive but poor products actually have a clue. They are not curious about their products, they don't care about their product or have any pride in what they are doing. They found a market where they could make money. I think it's that simple. I don't think they're actively trying to scam people. Hi-fi is just not very interesting to them. But money is.

I wouldn't agree with that they don't know what they do. I think that the real culprit is to trust listening tests despite measurements telling otherwise, thereby ignoring the wealth of audio knowledge acquired by scientists in the preceding 80 years. They confuse pleasure with accuracy: a transparent unit shows all flaws in the recording which a non transparent unit may hide, so the transparent unit must be bad. What they miss is that good recordings sound better on transparent gear.

I have to admit that in the past I belonged to the "pleasure" camp: I prefered good sound on many recordings to excellent sound on few recordings. This is a totally valid position. But I never said that my choice of gear was better than transparent gear.

 

[LTig]

[..]
On top of that, they have this story of how the prototype led to creation of this product. But now we see that they used a different transformer than what impressed them?

So much to the year long voicing ...

 

[audimus]

They confuse pleasure with accuracy: a transparent unit shows all flaws in the recording which a non transparent unit may hide, so the transparent unit must be bad. What they miss is that good recordings sound better on transparent gear.

This is a false dichotomy. Subjective preference may even like equipment that color good recordings over an ideally transparent one. Sensitivity to sound in volume and frequency along the spectrum varies. As one ages for example, people lose not only sensitivity in range but higher frequencies may also cause more listening fatigue. Or lower frequencies, may be difficult to hear so they don’t actually hear what the artist or the recording engineering intended. A coloring piece of equipment if it changes the balance to what is pleasurable to them would be preferred over a perfectly transparent one. To say that is some human cognitive failure and you find nirvana by forcibly getting away from it is rather presumptuous.

 

[GrimSurfer]

Ted Smith answered few minutes ago on PS Audio Forum:

"tashnishedears has stated my feelings and intent well. I can lower the noise in the audio band and more and more aggressively filter the resultant ultrasonic noise: but everyone that has listened to that likes the sound less (tho I certainty expect that some would like the filtered top better.) If someone doesn’t like the DS’s sound then the DS isn’t for them, no problem, there are a lot of fine DACs out there (and TTs, etc.)
I could skip the transformer, but then the DS would integrate well into fewer systems and have more analog noise. Sure there are a lot of better transformers out there, but they cost too much for a product at this price point. I’m reasonably happy with the performance of the transformers we use. When I started the project I thought that transformers were crazy for this application and did a lot of work that avoided them, but the very first time I simply passively filtered a DSD stream with resistors, caps and a transformer I knew I was on the right track and I had to learn and changed my mind about transformers.
I’m not going to waste my time reading and rebutting the other stuff at his site, I’ve been there before and see how he treats people and how he learns. In any real conversation each party must expect to possibly change their mind. I know that I’m not going to change my mind based on anything amirm says and I know that he’s not going to change his mind based on anything I say. There’s no end in sight in such a circumstance and I don’t need to waste my time making him happy.
I wrote what I thought about his review earlier and knew full well that someone would point him to it. I have in the past privately emailed some more detailed rational for the choices I’ve made to some members of this forum, but some of those private emails were immediately posted on other forums so I have stopped answering technical questions to most people in email.
As anyone who has been here for any length of time knows I’m happy to answer questions that are asked in good faith and I think many of the above questions deserve a good answer, on the other hand I’ve answered most of the questions on asked on this thread before elsewhere (even when I knew that some of the posters were trolls.)
Some people thrive in a contentious environment and some people like a spirited debate, but I don’t enjoy either now that I’m no longer a teenager (no denigration or judgement intended about other’s who are different than I am) so I’m not going to read any more of this thread."

He chose his approach to DAC design, now he's asking everyone to accept that the measured result is below par. I don't see much honor in this...

I've found Amir to be a very reasonable fellow... even at those times when my sense of humor or moral outrage at the audio business and its characters get the better of me. He's that way with others too, so it's a bit unfair to suggest that he's anything other than reasonable and, in my experience, very patient.

I can understand not wanting to get into a public debate because of the potential for things to devolve into (a) a popularity contest or (b) a cat fight. I'd be much more impressed to learn, in a month or so, that Ted contacted Amir and was able to suggest a mutual acceptable test regime (emphasis on the mutual) that resulted in a better results for his, and other, products. The cynic in me says this isn't going to happen for a variety of reasons.

Contentious environments and spirited debates are cornerstones of the scientific method. It's a shame that Ted doesn't understand this because this kind of challenging environment is crucial to advancing the SOTA.