The very expensive Linn music servers use an ethernet connection to an NAS drive (as I understand it; i.e., quite imperfectly). Is this intrinsically superior to a USB connection, or is the interface irrelevant? |
Chris, your question about repairing source material jitter involves a bit more complexity than what the Esoteric Rubidium is actually accomplishing. A good way to think of exotic reclocking devices (such as the Esoteric) is they are repairing the myriads of synchronization issues associated with the abysmal SPDIF connection. With a SPDIF's flawed approach, the clocking information is interleaved with the music data. The Esoteric Rubidium's incredible improvements seem to prove how poor the idea of interleaving clock information along with the music data has been all along! Of course, we can do this much more elegantly if we don't even try to interleave the clocking data on top of music in the first place. Can we say "USB" ;-)
Lapaix; Linn seems to be on the right track in choosing a high bandwidth connection. The ability for a DAC to be able to talk "back and forth" to the computer hard drive (while the music is playing!) assures a much better opportunity to achieve a perfect data tranafer to the DAC. It also is apparent that a standard USB connection easily exceeds the bandwidth requirements for the DAC to talk back and forth to the computer. Is Linn's higher bandwidth approach even better? I think the jury is still out here. I do know that the USB DAC I heard sonically eclipses Linn's best offerings by MORE than just a hair. Perhaps Linn should take a second look at the other parts within their music servers? If they can develop similar advancements elsewhere, the stratospheric pricing of Linn's music servers could be more easily justified IMHO. |
Ehider, I agree that too few direct comparisons are made between RBCD and the benchmark of great vinyl when judging the performance of a CDP. However, I make this comparison every day, and have come to the conclusion that it is indeed possible for a traditionally architected CDP to equal or surpass an excellent vinyl front end. Moreover, as the CDP's analog section is critical, I would like to know more about the analog section of your USB WDP(Wet Dream Player). |
Dgarretson; Ha! You really cracked me up with that 'WDP' moniker! I am not sure what I am allowed to say about the prototype USB DAC that I heard - The digital front end consisted of an Apple computer (that had the CD's transferred to it's internal hard drive via error correction) and it is connected to the DAC via a USB cable. The true proprietary information is not in my hands. It would be up to the designers to reveal once they launch this DAC sometime this year. |
Ehider, are you talking about the Daniel Hertz USB DAC with the proprietary Burwen Bobcat DSP?
Chris |
Dazz it looks like the Daniel Hertz USB DAC is PC only with the Burwen Bobcat DSP a plug in for Windows media so I doubt this is the "WDP"...waiting for a response from Ehider though. |
Hi Chris, The prototype USB DAC that surprised my ears is not related with the Burwen Bobcat/Daniel (note, a few audiophiles with ears I trust say that the Burwen is very special indeed). The USB DAC I heard was a pre-production unit from a company most of us don't hear much about. I am thinking I may start a specific thread with the USB DAC's name and some other details when the company gives me the "green light" to talk about them in detail. |
Drubin, You should review the G-0R's review at 6moons also where they review Esoteric P03/D03(?) combo and its effect when used. I thought 6 moons review quite different than Robert Harley's impressions. |
Thanks, I will check that out. |
Drubin, I just finished Robert Harley's complete review in AS and I was wrong!. Both 6 moons and AS have similar comments with use of G-0Rb clock. As 6moon best describes as "Zandenification" of sound. Not a bad thing! |
There is some confusion in the above thread about USB (at least as we know it....) Here is what Steve Nugent has to say about this subject:
USB indeed does transfer a clock, similar to the way that S/PDIF has an embedded clock. The primary difference between the two is that the chips available for clock recovery for USB are actually better at jitter rejection than the receiver chips for S/PDIF clock recovery. That is the primary advantage of USB, as well as an apparent lower sensitivity over long USB cables compared to long S/PDIF cables.
And the Synchronization comment is false. These interfaces all use forms of Phase-locked-loops or delay-locked-loops. The rubidium clock or a Superclock are just providing a low-jitter clock for the PLL. Nothing to do with "synchronization". Both USB and S/PDIF have embedded clocks.
An I2S interface actually has separated clocks, so this is a big advantage and results in even lower jitter than USB or S/PDIF.
Steve N. |
So let's try to make this less confused *. Here are some of my points:
- This Esoteric clock and other's like it are not the wave of the future IMHO. They are more 'band-aids" trying to correct issues of our past way of doing digital transports and DACS with that horrible SPDIF connection!
- The future of "amazing sounding digital" (read; As good as analog, if possible) will be coming from manufacturers NOT using SPDIF connections, or Esoteric re-clockers, but from OTHER forms of connectivity, such as USB.
- The "non-technical" reason that helps an audiophile "wrap their head" around the reason a USB connection can have the ability to sound much better is do with the fact that it doesn't interleave* clock signals on top of music data like the SPDIF format does.
*Please note; the above statement is a VERY SIMPLIFIED way of explaining this point. Not all of us went to engineering school! I will attempt to explain the technical detail in my direct response to Agear below;
Warning, the rest of this posting is VERY LONG.....
Yes Agear, your statements are absolutely true "in form". There is quite a bit of engineering "tech speak" that I didn't explain to Audiogon readers (such as yourself) who actually understand the detailed technical side of digital interface methodologies and their inherent topological underpinnings.
Such as;
-The clock signal itself on a USB is much different than that of a clock on a SPDIF. So much so in fact, that many engineers don't even think of it or label it as a clock anymore as compared to "the clock" within a SPDIF connection methodology. Here are some reasons why they think this way. The timing is sent on the USB sort of like a "when to start" signal. Sort of a "Hey USB! You are going to get a stream of digital data in the form of bits, now GO!" This is not the same as a clock being put on top of a continuous data stream like in the SPDIF. That is where the HUGE difference is that supports the "interleaving" statement. It also explains why you aren't having the major sync ssues associated with SDIF. In the end though we are talking about the actual interface between the transport and the DAC's input receiver and the inherent connectivity downfalls associated of the actual "clocking" data itself, how it is configured, how it is married to the data stream and how that clock information is different "in form" as opposed to a SPDIF and it's real ugly sonic mess comparably.
Both USB and I2S connectivity are a superior way of connecting digital transports and DACS than SPDIF comparably. The conversion to I2S can actually happen in a properly designed USB Dac too. This conversion to I2S would happen later time in the digital chain itself. With this in mind, I do think we need to think of a properly designed USB DAC as having I2S (it just starts with USB cable before I2S). What does this all mean to the comparison of USB versus I2S connections if we convert earlier in the chain as opposed to using a simple computer USB connection? Well, that is where the sound quality itself will show the merits of both of these connectivity methodologies. Here are my thoughts ; since a computer has a built in USB connection, it makes it much more straight forward to connect the computer via USB to the DAC (Can we say "elegant"?). It also makes it easier for the audiophile to hook up (Can we say "simple"?) There is less cost associated with the USB connectivity (Can we say "We like to save money"?). Lastly and most importantly; the most impressive DAC I've ever heard up to this point was a USB Dac. That is where the "proof is in the pudding" for myself. Whatever format gives us the best sound and is actually closest to analog is where are measuring stick should be. All of these technical "explanations" and "tearing down" the engineering side of digital is interesting but the end sonic result is what really counts IMHO (not necessarily the technical methodology).
Since Agear pointed to Steve Nugent, I'll let some of Steve's statements outline what I've been trying to convey also (this information is from Steve Nugent himself):
"In an outboard USB converter, the data is received from the sending computer and precise timing information is added. The jitter from the computer clock can be effectively eliminated. The interface is then translated into an interface that a DAC can understand, such as S/PDIF, AES/EBU or I2S (the native DAC chip interface). The clock that generates the timing can be very precise and does not depend on data rate coming from a rotating optical disk, like a CD player, or the rate at which a hard disk is read. It does however depend on uninterrupted data flow from the computer." |
Enjoyed reading this thread, but until a stable, audibly proven, simple and affordable solution is in place with say, flash drive PC transmission (via which cable) to my Dac, my CEC transport might go to Joseph Chow for some power supply reworking around the clock, he's good at addressing low-level signals. |
Eric, I agree in essence with what you are saying. S/PDIF is inherently flawed. USB has advantages in terms of the ease of reclocking, etc. However, not all USB interfaces are created equal. Steven Nugent himself told me that there is a fair amount of variability in the quality of USB reclocking chips, which is where the $ is. That being said, I wonder if the sonic attributes of this WDP (nice Dgarretson....) are simply a byproduct of the USB interface or is it something more? I think you are operating under certain assumptions about the purported sonic attributes of USB data architecture. There are USB products out there which, while very good, are not a quantum leap beyond current offerings.
I will leave you with a quote from the Benchmark gang taken from a Stereophile thread:
We did measure the audio performance (Freq response, THD, IMD, etc) of the USB input, and it was completely similar to the all other digital inputs of the DAC1 up to 96/24. We also did listening tests. I am continuously conducting this test (as we speak ), as are several others here at Benchmark. Testing with a CD transport feeding the Coax input, and the computer feeding the USB with the same music, no one has been able to differentiate the two inputs.
--------------------
Elias Gwinn
Engineer
Benchmark Media Systems, Inc
www.BenchmarkMedia.com |
Triode, I have the G0s working with the P0s VUK and DCS Elgar plus. Have you heard the Rubidium clock in action with the Esoteric , DCS, or EMM separates? Have you done A/B comparison?
Some fools buy "crazy" things, but the others speak about things they don't know. WHy don't you tell us about your experience with the Rubidium Clock and explain your statement?
Kyomi Audio |
Ehider, "I am thinking I may start a specific thread with the USB DAC's name and some other details when the company gives me the "green light" to talk about them in detail"
Do you have a formal or informal relationship with this un-named company?
Can't wait for your thread on the specific DAC you are mentioning. I have a Pro Mac waiting for a higher purpose now, just in case.
Reading the comments from the reviewers regarding the Memory Player, it seems like this a new paradigm, a new cult, or an alien invasion starting. |
Perhaps a naive question from someone technically challenged, but will any of this have an impact on, or improve upon, the performance of pc-based music delivered not by USB but wirelessly, as with a Sonos or Squeezebox? (Oh please, oh please, tell me it will!!!)
I think THIS is the real future of music delivery, whereby you DON'T have to plug a pc into your system via USB or anything else. Whereby you can sit anywhere in your house and pull up music and play it, via your laptop or your sonos, squeezebox, etc. This is truly the future. Hardwiring is NOT the answer in my book. Convenience equal with reference quality playback is the answer. I wish more effort was being put into this aspect of delivery. |
Agear, IMHO you are absolutely correct that USB intefaces are not created equal. (If it was only that simple!). I think we will see just a select few USB based digital standouts in the next year or so. Most likely, many of their competitors will be "scratching their heads" to why they cannot achieve the same sonic greatness when they try to implement a USB connection within their digital products. Steve Nugent is absolutely spot on with his assessments regarding USB variability. Only a very talented digital design staff (that understand digital like Steve Nugent) will be able to implement USB connectivity and actually achieve true sonic greatness due to the myriads of technical issues that Steve pointed out. As you surmised, the most important thing I've learned with this is that the SPDIF connection itself has always "sucked the life" out of what digital was capable of giving us. Of course, the Esoteric $15K Rubiduim clock probably helps fix some of this. ;-)
Bosrt; The wonderful pre-production USB DAC I heard was actually by accident. If their production USB DAC sounds as good as the beta unit I heard I think I will be "beating the drums" very loudly about it. I am so VERY TIRED of seeing the multitudes of huge dollar digital offerings that are being talked up in the rags and on the audio forums that don't actually meet the expectations? (Can we say "almost everything"). I think many audiophiles are getting burned out with digital as they spend STUPID money yet still end up flipping their digital front ends year over year. When are we going to see the super digital "revolutionary" product actually going to meet the hype about it?
BTW: Your "Alien Invasion" statement really cracked me up! |
Thanks Ehider for spending the time/energy with these topics. |
Eric, you soooo right. We are all sick of this crap. I have been researching and researching and waiting for "that" product to appear but to no avail. One of the sonic themes that comes out in reading reviews pretaining to digital audio is a certain thinness of sound...ultra detailed yes, but lacking warmth, bloom, bass weight, etc. That is what I crave. You mentioned the Memory Player, and while it sounds promising, who is 10K+ lying around? Anyway, I am planning to a little blinded, A+B testing of digital front ends in the not too near future, and I would like to involve non-audiophiles with good ears and music backgrounds (my wife for example) to keep things real. The potential contenders at this point are:
1. Granite Audio 657 (my CDP)
2. Bolder modded SB3 (Ultimate mod)
3. Modded Sonos + Pacecar + DAC (Empirical Audio)
4. Sonos (w/ ? USB mod or converter) + Exemplar USB DAC
Should be interesting..... |
Please report back your findings, Agear. |
So, why not go for I2S?
Chris |
The I2S is what Steve from Empirical highly recommends.
I believe until an audiophile wireless solution ever falls into place, this is the preferred connection.
You'd think with all the computer and digital technology someone would have the answer by now. |
