Originally Posted by Shahrose
When I showed you measurements from AMB's website of my DAC and amp, you said measurements don't tell the whole picture, yet here you are assuming what other people's gear sounds like from measurements and also use them to convince others of the hiFace's superiority.
Notice the difference between my posts and yours. You come across as aggressive towards anyone who disagrees with you and attempt to assert your opinion on anyone who does so. Do you see anyone else telling you that your gear is not revealing enough, even though that may very well be the case.
For example, I could just as easily say that your headphones aren't revealing as much and I own them so I know for a fact they don't. I could also say your amp isn't up to snuff, or that your DAC is just imposing its own sound signature on the transport's (BTW I've had people listen to the Reference 1 and my own DAC and say that there is little difference). These claims would be equally valid as yours. However, I choose to instead accept the fact that your tastes and gear may produce a result different than mine and don't try to rebut your opinion or try to change your mind through my own experience.
There are no right or wrongs in subjective listening, I thought you would have learned that by now. I take issue with is the fact you feel the need to consistently tell people they are either wrong or that there is a problem if they don't hear the exact same things as you do.
Further, I think you've misinterpreted my decision to buy the cables you recommended. The quote you bolded is meant more as a figure of speech to show that I wasn't a firm believe in these types of cables...you've used it to (wrongly) assume my intention. If anything, it shows the respect I have of your findings and reviews. I bought something expensive, against my own judgment, only because of your insights. I'm not sure how anyone can see this in a negative light.
I am not contradicting myself about measurements; you probably didn’t understand fully what I was trying to say. So allow me to be clearer. I am not saying that measurements are good or bad as you are implying, but what I am saying is a lot more subtle and complex than that.
When you have only a limited set of frequency domain measurements (FR, THD) they are not enough to fully grasp the performance of a unit as the time domain measurements (jitter, impulse response, transient intermodulation, ...) might have a bigger impact on the sound. Since it is not easy to measure all those parameters in DACs and amps, it is hard make a judgement solely basing the opinion on the FR and THD measurements.
For the source, it is somewhat a different story. If you have a source with low jitter, low phase clock noise and proper impedance (75 ohms for coaxial and 110 ohms for AES/EBU) you are pretty much “there”. So designers know what ideal source they should be developing: a source with a vanishingly low jitter and clock phase noise, and with proper impedance termination.
If you look at all high-end transports be it CD transports, PCI cards or usb sources, they all share some common points and they are all trying to achieve the exact thing.
Of course, if you are comparing 2 units with the same amount of total jitter, they can still sound differently if they don’t the same distribution of jitter according to the frequency. So in that case, since no one (to my knowledge) seems to be able to correlate the jitter pattern with what hear, subjective listening can play a big role in selecting which transport “sounds best”. But that recommendation would be specific to the particular DAC it is being used with and its characteristics: DIR, PLL, type of DAC chip, “colour” of the output stage. A different DAC with different characteristics would yield a different result.
However, if we are comparing 2 units with different amount of total jitter: say unit A has 1ns and unit B has 20 ns, then one can easily say that unit A is better than unit B.
Or if you wish, we can look at the problem from another point of view: If you wish to achieve true 20 bits performance, you need to have jitter levels lower than 4 ps (at the analog output of the DAC). So the higher the jitter, the lower the effective resolution (in the time domain) of the DAC is. For more information you can read this interesting research paper about jitter and building high resolution DACs (http://www.iet.ntnu.no/courses/fe811...t_audiodac.pdf
So to sum up about measurements, I am not saying that measurements are good or bad. I am saying that depending on what component is being measured, and what type of measurement we perform, we can achieve different level of confidence about evaluating that gear. So while my comments might have seemed random and contradictory, this little explanation will hopefully clear up my thought process on measurements and subjective listening.
While I think that because of the lack of understanding in certain areas (and because of personal preferences), subjective listening is still very important for certain type of equipment amps, speakers, cables, headphones ... I do however believe that when it comes to sources, one has to aim for the absolute transparency. If anything is lost at the source (because of jitter for example) it cannot be recovered later on the chain. By “component and cable matching” you can mask certain faults and achieve a pleasing tonal balance, but you would lose valuable information that would have brought us closer to the original wave form of the recorded event.Hiface & subjective listening:
Is the Hiface a perfect transport? No
Is the Hiface the best match for every system? No
Is the Hiface the closest to perfection (in the affordable category)? Yes
If you look at the measurements of jitter at the digital level, you will understand that the performance of the Hiface is exceptional. The Hiface had jitter measurement of 1ns (close to the limit of the test equipment). That was better than the Lynx Professional card and also better than a Nagra recorder and a CD player. On a Stereophile measurement, the EMU 0404 usb (which is also async) had a jitter of around 8ns. Even digital cables can have jitter levels of a few ns.
So the Hiface can output a cleaner digital signal than most PC sources out there. So that is a fact.
Another fact is that a lot of people have listened and liked the sound of the Hiface. Weirdly enough, even people using well designed high end DACs (Lavry, Northstar, Audio-gd Ref1, Audiomat ...) seem to have liked what the Hiface did to their system. So if there was anything intrinsically wrong with the Hiface, it would have shown on those systems.
On the other hand, we have a few reports of people who didn’t like the Hiface because it sounded compressed, constricted or some other thing. So what to do with those reports?
First, before to answer that question, I will just tell you an anecdote on how the sound of the Hiface can be manipulated. By using a 18 feet Belden digital cable, I achieved a bigger, more laid back (and more diffuse soundstage) from the Hiface. Another trick that achieved the same effect was to use upsampling to 96K with minimum phase and setting the passband at 90% (instead of the standard 95%). I got pretty much a similar effect in nature (but less in quantity).
So by generating higher amounts of jitter (by the means of an 18 feet Belden cable) or by manipulating the waveform (SoX upsampling with unusual settings), I achieved a result that went towards what the more jittery achieved.
So what to make of that? Well, my guess is that if you inject high amount of jitters at certain frequencies (with a little bit of trial and error) you can make the Hiface replicate the sound performance of the Teralink-X.
What people are hearing with jittery transports such as the Teralink X, Emu 0404 usb... are distortions. Those distortions can be annoying in the case of the emu0404 usb or pleasing in the case of the Teralink-X but they remain distortions nonetheless.
So by now, you should see where I am going. If on a few specific systems, the Hiface is found to have a “compressed soundstage” or a “dry sound” for example, it simply means that the excessive warmth of previous components were masking that. So since the Hiface is merely a digital transport (with relatively low jitter) that doesn’t make sound on its own, does it mean that the compressed soundstage (for instance) is coming from the Hiface or from the DAC it is being paired with? Usually, the other transports are described as having a bigger soundstage but less defined imaging and less low level details. Those in my book correspond to the description of jittery transports.
Again, as I stated earlier, in such a case, I consider that the compressed soundstage is not the “sonic signature” of the Hiface but that of the DAC it is being paired with. Limitation of the test gear:
You have mentioned several times that the Silver cabled Sennheiser HD-650 I used for my tests were not as resolving as your Sennheiser hd-800, and that is probably the case. However, if I can detect those differences on the hd-650 and if those differences also happen to correlate with measurements, then I say that those differences were big enough to be heard.
As for the DAC being used, I never said that my DAC was a reference class one: What I consider as a reference class DAC is something like the Esoteric D-01, the MSB Platinum, DCS, Lavry DA2002, Reimyo... All of those of DACs unfortunately cost $8000+. So in shopping for a mid level DAC, one has to look for one that has less compromised than others. I settled for quite a while on the dac19mk3 and I sold it last week in order to get the dac19dsp.
By trying out the dac19mk3 for several months (you can read my review of the dac19mk3) I was able to detect that its analog section was far more transparent than its digital section. The sonic signatures of the PDM100 and DF1704 could clearly be heard through its analog output. That is one of the reasons I decided to upgrade to the DAC19dsp which uses a custom made DSP1 supposed to be better PMD100 and DF1704 (more processing power, configurable oversampling and dither options, de-jitter function, ...). I am very pragmatic: what I liked about the dac19mk3 was the transparency of its output stage and the naturalness of tone of the pcm1704 uk being used. What I “disliked” about it is that the 2 digital filters had 2 distinct sonic signatures, and I spent my time going back and forth between them. Each one of the filters had distinct strengths: the DF1704 was fast and utterly transparent, and the PMD100 was warm and had a superior tone. With both filters the dac19mk3 however (subjectively and to my ears) outperformed any other sigma delta based DAC I have compared it to.
So when I was comparing usb to spdif converters, I was not using one DAC, but I was using 2 reference DACs (DF1704 and PMD100) and I would also check my findings with other DACs I had on hand as well as other digital cables.
So when I am saying that the Hiface sounds like this or like that, I have already tried with a big number of configuration (DACs, digital cables) and against different usb to spdif converters.
Also, when I try equipment, I try to understand as much as possible what is going inside. For example, the Musiland (and other converters such as the Teralink) is very bad at generating a 44.1 clock. So I test it not only with 16/44 data but also with 24/96 to avoid that dreadful 48 to 44.1 clock generation. But for the sake of being concise, I don’t cite everything I test, I compile and synthesize data.
So as you can see, I am well aware of the limitations of my test gear. But by having of few equipment around (to serve as different points of references), and by understanding the technology behind each equipment, I am confident enough that my findings are not specific to my system but can be generalized to other systems as well.
So when I am saying that your DAC might be the culprit or might not be as transparent as you think, you shouldn’t take it as an insult or as a direct criticism. I just wanted to attract your attention to the possible limitations of your DAC since it seemed to me that you consider it beyond reproach.
In the quest of perfection, the Hiface is a relatively closer to perfection than either the AMB Y2 or the dac19mk3. If there are perceived colorations in a mid level system when inserting the Hiface, it is more likely the intrinsic sonic signature of the DAC than it is the sonic signature of the Hiface.
So to be clear, I don’t disagree with your subjective listening results. What I strongly disagreed with you is the interpretation of those subjective listening results which could be misleading.
If the Hiface works well in 80/90% of the cases, it is close to a miracle in this audiophilia game. Try dropping a revealing headphone amp in many different systems and you would see that will have far worse positive results and acceptance.
Of course, there will still be a few cases where the Hiface won’t give the best sound. But to my knowledge, those cases remain rather small and have more to do (in my opinion) with a mismatch combination with the DAC than with the Hiface.
Again, I don’t think the Hiface is perfect but it is closer to perfection than the other converters and Jkeny’s mod is a good step towards perfection. Final notes:
My intention with this post is not to start a debate. It is to be more explicit about what I have previously said.
Reviewing a usb converter can be tricky if one doesn’t fully understand the science behind it and the way it interacts with DAC (jitter spectrum, clock phase noise, type of digital filtering, oversampling ...). I don’t pretend to fully understand all that is going on. However, I am trying to do so: I have read many research papers on jitter, DACs, digital filtering, temporal resolution... and I continue doing it.
So by combining theoretical data, measurements (when available and relevant) as well as subjective listening (with the proper equipment), I am trying to form opinions that go beyond this sound good or this sounds bad.
Of course, for “fine tuning” a system, one has ultimately to rely on subjective listening.
However, in my opinion, a usb to spdif converter should not be considered a tool for fine tuning a system. Any loss at the source simply cannot be recovered later (and something like a motherboard coax or a Teralink X represents a loss in my opinion).
Also, I don’t recommend using interconnects and digital cables for fine tuning as the more transparent the digital cables and the interconnects, the better the results.
So what does it leave us with? One can seek the “coloration” either in the amplifier or preferably in the speakers/headphones themselves. One can also try with different power filtration and vibration control techniques. In fact, a good power supply (outside of the components) and a good vibration control do no really colour the sound as much as they reduce unwanted colorations.
This will hopefully show you that I am not “closed” to subjective listening, quite the contrary. However, in some cases we know what to measure and how to build something to sound good in most systems.
Let me give you a final example. If for example I tried the top of the line CEC transport or the Empirical Audio Pace Car in my system and they sounded compressed, I won’t blame them. I would go and look elsewhere in my system (digital cable and DAC for instance). I am simply applying logic and considering what would be right 99% of the time. Of course, there is the possibility that those specific units would be defective, but at least I will try to test them with different gear to make sure that I am not simply uncovering an intrinsic characteristic that was buried (and blurred) under the noise jitter before.
Well, this post ended up being longer than expected. I hope that is clear enough. My intent is not to start a debate but to explain why in my opinion (and according to my research) we hear different things and how we should interpret those different findings.