Do the various Philips drives or the TEAC VRDS transport mechanism each have a particular sonic signature regardless of which maunufacturer uses them in their designs? Exlibris, I see that you have asked this question couple of times in this thread. I would like to answer that. YES, both these transports have a distinct sound, meaning one distinguish one from the other. Simplistically speaking the Philips transport sounds more like a good suspended TT while the VRDS sounds like a well-built high mass TT. By the way, I am new to TT but it was interesting for me as well I was able to co-relate the sound of these transports to the TTs. And more interestingly the VRDS is indeed high mass design. Does that mean an all analogue TT and a digital transport have similar design considerations in some areas ? I dont know but it does seem likely to me. Coming over to specifics: 1. The VRDS is clearly more extended at in the low frequency region and goes really deep and articulate. The philips doesnt articulate deepest bass notes as well as the VRDS. You can sometimes clearly hear the Philips rolling off bass beyond a stage. 2. The VRDS presents an extremely stable and rock solid holographic soundstage, almost with an iron fist. Listen to a big classical sypmhony on it, you will know what you were missing all these days. You will also hear soundstage layers in a more obvious manner in a VRDS. The Philips sounds "normal" in this area. The soundstage is good but slightly moving, a bit hazy and not so holographic compared to a VRDS. You will notice this only if you hear a good VRDS in the same system, else the Philips will sound just fine. 3. Tonality: Here the Philips is one of the best performers of all transports I have ever heard. Tone and more importantly Timbre is extremely accurate in Philips transports. I have heard the early CDM1, CDM9, CDM12 and now CDPro2M. All of them exhibit this character. They just to it near perfect. The VRDS has a timbral coloration towards the darker side. I have heard about 4 VRDS including the latest ones and they all have it. Simply speaking I have not heard any other transport as tibrally accurate as a Philips. I am very sensitive to this aspect of music reproduction so it is almost the first thing I hear in any system. 4. Philips in general also sounds more fluid, and a bit livlier than VRDS in general (again suspended vs non-suspended thing). In general, VRDS sounds special, as in real hifi, while Philips sounds normal but more natural, more like music. If one has to choose between these two transports alone then it will boil down to genre of music a lot, a western classical listener would like to have a VRDS with him even in his coffin. A jazz, blues, country listener will love a Philips and may not care much for the "special effects" of a VRDS sound. A rock listener will be happy with either. BTW, I have not yet reached a conclusion on this but many Philips transports I have heard also have very good PRAT (suspended design?). |
I am sticking with my RAM - modded CEC TL-1x, recently refreshed and updated by Nick at True Sound with a new belt, etc. AES/EBU output through Sextet digicable to W4S DAC2 (which replaced a Dodson DAC). Can't see why I would want to replace this elegant, smooth operator, dead reliable beauty, or move to computer audio(ugh!). Call me a Luddite -- but a musically satisfied one.
Neal |
hi grateful:
i too have the ps audio transport. its advantage is that the disc disc is fed from ram to the dac. it does not spin while you are listening to the music.
it is , however, highly sensitive to the digital link.
it is hard to judge the sonic attributes of the pwt because there is a dac connected to it. when i connect a tube dac i hear a tube like soun, wheras, when i use the ps audio perfect wave dac, the sound is very much as you describe.
i use a harmonic tech hdmi digital cable with the ps audio dac and coax with a tube dac. |
This tread has been dead a long time, I'd like to give it a bump due to much has changed since the last post.
Personally, I replaced a Accustic Arts Mk ii transport with the PS Audio PerfectWave PWT Transport. Much more open and transparent with tighter bass response and more actual timber of strings.
What are other's experience with the PS Audio PerfectWave PWT Transport or any others? |
Tottally agree - XL-Z999ex is really one of the greatest. But there is sth much better on the market - XL-Z1000. I have both of them (100V version), so I had possibillity to compare. Based on my observation, using digital (RCA) connection between both and DAC from XL-Z999ex. Sonically huge difference - bigger, quiter, more stable sound, wider sceene, much more details. Even power cable - integrated version gives possibility to use separate one (NBS Monitor0), in transport case - there is one built in. |
& u can always have a back up hard drive |
"If your transport breaks, you repair or get a new one. If your HD goes south, it gets tossed with all you stuff on it or you have to buy an adapter kit to hopefully download available content that's hopefully not corrupted."
Bankup is your friend.
Hard dirves are not that expensive these days especially compared to the high-end audio gears, even compared to the cost of repair...
It's not an issue at all.
These days you store all your pictures on hard drives, why not all your music.
It'll be one of the major way of listening to music in the near future. |
If your transport breaks, you repair or get a new one. If your HD goes south, it gets tossed with all you stuff on it or you have to buy an adapter kit to hopefully download available content that's hopefully not corrupted. |
Anything's possible Teajay. If I get a chance to demo a really top-flight transport
in my system I certainly will. That said, my hard-drive based music server isn't
going anywhere, no matter what. There is just nothing like having any song or
album in my entire music collection at my fingertips. You should see the way
iTunes 7 allows you to scroll through your music by album cover. Very cool.
Sorry, I know this is off topic for this thread. |
Pardales, I think you might be surprized how much of a sonic improvement you would hear with a reference level transport compared with a hard-drive.
I'm no engineer so I don't know why a reference transport would perform better then a hard-drive or an average transport, but every time I have gone to a better transport, right now my reference is the new Accustic Arts Drive1-MK2, the sonics get better, not just different, but a true improvement. |
No, I have not used any of those. The transports I have had in my system tested
against the hard-drive is the newer CEC TL-51X (I think I have the model right)
-- it retails for around $1500. I have also had some older model Denon and
Sony CD players that were touted for their excellence as transports (in their day
5-6 years ago). None of them sounded better than the hard drive. None of them
sounded worse either. I am not saying transports are of no use.....but combine a
thoughtfully constructed hard-drive based system (including a good device for
between the computer an DAC) with a high quality DAC, and I think one would
have to spend a lot to get a significant improvement from a conventional
transport.
Hey, I might be wrong about this. But I think hard-drive based music systems
can equal some pretty nice transports. |
Pardales:Have YOU compared in your system a hard drive against a reference transport: one of these...
Zanden 2000
CEC TL-0X
Metronome Kalista; T2-i Signature; and T2-A
Esoteric P-01; and P-03(?)
EMM Labs CDSD
47Labs PiTracer
Weiss Jason
Accustic Arts Drive 1
Ensemble Dirondo
Wadia 270se |
I am no expert. Others can speak to, and have in other threads, the merits of the hard drive. For example, Steve at Empirical Audio has written about this on threads in the computer audio forum and at his website. |
Pardales, could you please elaborate on the inherent musical superiority that hard drives, currently based on magnetic read/write heads on multi-platter Random Access media are expected to have over optical drives? |
|
John,
Thanks for the link. That really does put things in perspective. |
"Here is a very simple example of why a transport makes [A] difference."
In real life any fool with a pair of ears can hear that some with error free output sound like crap and some with error free output sound like music. Exlibris, Your take, using a pair of ears, can also find some support from a pair of eyes (actually, one eye is sufficient). Check out the following link for a pictoral comparison between Esoteric's VRDS-NEO transport and some other transports, including some that are used in top-tier players. For me, it's an example of a picture is worth a million words: http://www.aplhifi.com/phpBB/viewtopic.php?t=560 Thanks for your thread, it's been very informative. Best Regards, John |
I finally came back to this post after starting it way back in March. I'm sure no one is still following it but if they are, here is my take (to quote Lktanx with an important modification):
"Here is a very simple example of why a transport makes [A] difference."
In real life any fool with a pair of ears can hear that some with error free output sound like crap and some with error free output sound like music.
Yes, pragmatism, empiricism, and experimentation are all that I have to offer.
One can continue to argue that transports SHOULDN'T make a difference but to argue that they don't make a difference is simply un-scientific:
1. You've hypothesized that transports shouldn't make a difference to the way CDs sound;
2. You run a controlled experiment where you test your hypothesis;
3. The experiment shows that there is an enormous difference in the way two transports sound (even though both provide 'error free' output to the DAC).
4. You must scrap your hypothesis and move on. |
We may have gotten a bit side tracked from my original response. Here is a very simple example of why a transport makes no difference. We build the following hypothetical system. This system consist of 3 boxes interconnected. They are:
A. Transport only
B. RAM only
C. Digital filters/DAC/Output stage
These 3 boxes make up a complete CD player. The following lists a step by step process to listen to music.
1. Download entire song from Transport into RAM, error free of course.
2. Turn OFF Transport and disconnect it from RAM.
3. Discard Transport into an incinerator and burn it.
4. Play music from RAM thru box C which has the digital filters and DAC.
|
Germanboxers,
after your last post, we are probably on the same page because of your statement:
>> ...(and I view the transport -correctly or incorrectly-
>> as everything from reading the disk to just before the
>> digital filters, including motors, power supplies, etc
>> to accomplish this)
wish that you had made it amply clear to us of what you viewed as a transport.
I went back & skimmed thru your dialog w/ Lktanx & I re-noticed that all the discussion was based on reading data off the disk & making suitable corrections if error(s) occured. Naturally, I continued the discussion along those lines.
You are correct, all the other support systems in the transport do make a diff & your experience
>> ...but my experience with the effect transports have on
>> the sound in my system were with the ARC CDT-1, Theta
>> Data Basic, and a Pioneer DVD player using the digital
>> out...all using the same Kimber digital cable feeding a
>> Theta GenVa. The differences were not subtle, even
>> between the Theta Data Basic and ARC CDT-1.
confirms it.
>> Would using a well-designed linear power supply for the
>> laser optics accomplish the same thing?
I don't know if something called a "linear power supply" exists. When I read "linear", I think of harmonic & intermodulation distortions. These don't occur in the power supply electronics per se. However, non-linearities in the electronics driven by the power supplies can cause the power supply to leak into the signal path & bring w/ it noise, voltage/current spikes, ripple, etc. Power supplies can be made robust in that their voltage outputs do not sag easily, high current, fast response, low ripple/large charge reservoir, etc. The electronics can be designed to have high power supply rejection ratio or PSRR. The things VRDS-Neo has done to the drive itself + to the support circuitry goes a long way towards all this. The hope is that it will xlate to better sound. It'll be better than the other stuff on the market. Will it be better than their redbook VRDS used in the 861? It remains to be seen. Has anyone heard the VRDS-Neo & compared it to their redbook VRDS? Please share this info. Thanks!
>> Your statement that Japanese mfg's have been
>> overengineering since the 70's doesn't hold water.
what I meant to say was that I have not seen any other country engineer things ON A CONSISTENT basis as I have seen things from Japan over several decades. Things were substantially made in the USA too but when it sacrificed bottom-line profits, manuf goods were made cheaper immediately.
Contrary to this, what I have noticed in Japanese manuf, is that they 1st try to finds better ways to make the manuf goods while retaining their substantial feel. IMHO it is why Japanese automation & process, R&D supported by MITI are the world-class standard they are. Even the Americans admit this esp. in the auto industry.
With this in mind, I meant to say that a country like Japan would probably be the only one to want to tackle the CD transport issue. The volume of these VRDS-based CDPs is very small compared to the CD driver for mass market players. Thus, TEAC's payoff is small but it is certainly there. The proof also lies in the pudding - a CD transport like the VRDS is not available from any other country! True or not?
The one that comes close it Philip's CDM-Pro drive & I think that it is of the same calibre as Pioneer's Stable Platter transport. Correct?
The other major countries into audio like USA, UK, Italy, France, Australia/NZ, Scandanavia do not make VRDS type transports. Why?
Their collective markets are much bigger than Japan's so the financial pay-off from this high-level engineering is bound to fetch more money i.e. there is a higher incentive yet such a product does not exist!
When you say that TEAC did not create the VRDS as a marketing gimmick, I agree. I did not mean to say that anyway.
I think that we might not be talking past each other at this point. Hopefully we have cleared the air? |
Bombaywalla, the depth of my knowledge in the area of digital audio is not that great...I admit that. I am not a digital engineer. You are also correct that I didn't prepare for this discussion. However, it does appear that you have narrowed this discussion to just the reading of bits off the disk and have in some ways contradicted yourself. I am probably to blame for the former as I focused my response to Lktanx on read errors. My "ex-tempo" response was perhaps offbase or at least, too shallow? Perhaps we have been talking past each other (maybe not?), but my initial response to Lktank was a reaction to this statement In a modern properly designed player, transports should make NO difference to the sound. If this were true (and I view the transport -correctly or incorrectly- as everything from reading the disk to just before the digital filters, including motors, power supplies, etc to accomplish this) then any modern transport should sound IDENTICAL to the next...not almost as good or practically as good, but IDENTICAL. The issue of cost/performance is moot...they must sound identical. A Sony, a Wadia, a Toshiba, an Esoteric, etc should all sound the identical if feeding the same outboard DAC, right? Forgive my non-technical, empirical approach here, but my experience with the effect transports have on the sound in my system were with the ARC CDT-1, Theta Data Basic, and a Pioneer DVD player using the digital out...all using the same Kimber digital cable feeding a Theta GenVa. The differences were not subtle, even between the Theta Data Basic and ARC CDT-1. Both were noticeably better than the Pioneer player. I realize that there are variables still unaccounted for in this experiment; however, the ARC and Theta did not read to RAM and the Pioneer did. I asked why would Esoteric spend so much money recently on developing and manufacturing the VRDS-Neo transport when they were going to read the data to RAM? On your first point, you said something along the lines that the clamping system they use eliminates/reduces CD wobble which reduces the "surges in electrical current drawn from the digital supply by the laser optics electronics". You went on to say that "this has the effect of dirtying the digital power supply & this crud pollutes everything it touches". This explanation sounds reasonable and reinforces my belief that the design of the transport is an important part in the design a good digital player. Would you agree? Would using a well-designed linear power supply for the laser optics accomplish the same thing? I don't know...I'm asking the experts. I'm not so sure that Japanese culture has a great deal to do with Esoterics approach to their recent Universal players. I spent a year working for a Japanese manufacturer in Japan in the mid 90s. I would say Im fairly comfortable speaking of their culture. High-end Audio is a culture of its own whether in Europe, Japan, or the USA. Your statement that Japanese mfg's have been overengineering since the 70's doesn't hold water. The initial offering of all new technologies are usually over-engineered. RCA made some pretty substantial VHS players in the 70s also. You think the iPod will continue to be housed in the metal chassis for much longer? Im fairly certain that Esoteric did not over-engineer their recent transports by such a large degree for purely marketing purposes. This would be alot of expense and effort if it made no difference to the final sound. I've found Japanese engineers extremely practical in general and would fully expect them to focus their attention and investment on better digital filters, analog stages, and DACs if the transport made no difference to the sound. Certainly, they wouldn't tie the entire success or failure of a product to a multi-thousand $ "gimmick". Finally, I have no beef with "computer-based audio" and I'm sure it sounds great. My main point is that there are differences in transports. Whether this is due to corrupted power supplies, read errors, or some other factor...there are differences. I am NOT saying that the differences in transports are massive or that they are more significant to the sound than other parts of the digital playback system. Your statement that you are also blowing the importance of the transport -w-a-y- out of proportion, if I may say so. is entirely misplaced. I said that I have heard meaningful differences in transports in my first post...that's the extent of my "blowing the importance of the transport -w-a-y- out of proportion". Are we talking past each other or are we at least on the same page? Thank you for educating me on some of the technical details I may have misunderstood. |
Henryhk,
>> With regard to the Wadia not being 32x better....of
>> course. In high end audio, cars, wine ...u name
>> it...the marginal utility one derives from spending
>> each marginal dollar tends to decline....but the key is
>> each consumer's assesment of the marginal utility is
>> different.
you are correct in saying that for each additional $ spent, the improvement is marginal & its value judged by the person spending the $.
However, that is not the point I was trying to make! My point was, that despite the vast diff in price, the cheaper solution gave a very, very good performance. This seemed to suggest that merely a transport was not the major part of the equation when it came to reproduced music from a digital source. BTW, I still love my Wadia, I'm going to keep it & enjoy music thru it.
>> ...my opwn exp: with Meitner. the chg from the old
>> Philips modified transport to CDSD provides not a
>> marginal but major difference in sound quality.
IMHO, what you gained when you changed from the modified Philips to the Meitner CDSD transport was NOT just the transport per se. The new CDSD transport is probably implemented much better than the modified Philips in that it's better mechanically/structurally, better power supply/supplies, better clamping, better electronics, better clock or even slaved to the DAC clock, etc. All these other things is what has given you better performance overall & NOT that the new CDSD drive reads the data off the disk w/ more accuracy.
|
--------------------
Again, I don't know about audio CD players, but in the world of computer data if there was any substantive liklihood of that sort of undetected error from a CD read occurring, then how often would software installed from a CD fail to operate becuase what was on the hard drive did not match what was on the CD? Note that I'm not talking about corrected errors. In all the years I've spent installing software from CDs (assuming the CD was not damaged in some way) I have never had that happen. Not once. Ever.
--------------------------
I would like to further emphasize Tonyptony's statement above. With music CD players, the drive mechanism is running at 1X. When you install software, the latest PC CDROM drives are running at 48X or even higher. If the 48X drives are not producing errors, just imagine how trivial a 1X drive mechanism is with today's technology. |
With regard to the Wadia not being 32x better....of course. In high end audio, cars, wine ...u name it...the marginal utility one derives from spending each marginal dollar tends to decline....but the key is each consumer's assesment of the marginal utility is different.
As for transports, hard rides...don't know much about the latter but one thing for sure in my opwn exp: with Meitner. the chg from the old Philips modified transport to CDSD provides not a marginal but major difference in sound quality. |
"every CD player, even the cheapest one, has C1 and C2 CIRC error correctors"
Alex, I don't know about audio CD players in this regard, but the context of my comments was WRT computer CD drives. And in that environment this is not always the case. If you look here
http://www.daefeatures.co.uk/search.php
(and just hit the Search button to get all results) you will find that there are quite a few drives that do not have C2 correction. You will also note that there are some drives (though few) that do not have Accurate Stream, perhaps even more importatnt than C2 for clean audio extraction.
"So, if there is no error flag, this does not meant that there is no error; it means that C1 and C2 were able to correct the errors."
If an error is corrected, would you then agree that the bit of information now in the system is identical to what was on the disk (minus any jitter component)?
I don't think either Bombaywalla, Lktanx, or I are saying that having an accurate data source is all that is needed for audio to sound good. In my case I am saying that a server based data stream (when done correctly) may in fact be a viable replacement for a transport - from the perspective of assuring an accurate data source as your starting point. Once the data is assured to be accurate then you may be able at least to remove that component from the equation.
I ran a small experiment before posting this reply. I have three different CD drives in my (computer) system. One (the Plex Premium) is used for audio ripping and software program installation. I pulled a few CDs which were ripped from this drive and did a binary compare against what is on my music hard drive, each CD being tested in all three of my CD drives. What would you propose to be the likelihood that one of these undetected errors would be undetected in exactly the same way on each drive, and that an undetected error was matched exactly against all three drives with what had been ripped to my hard drive? All three CD drives are from different manufacturers, BTW. It did not surprise me in the least that the ripped audio files exactly matched what was on each corresponding CD, when read from each of the three drives. My sample is certainly not exhaustive, but I suspect fairly representational.
Again, I don't know about audio CD players, but in the world of computer data if there was any substantive liklihood of that sort of undetected error from a CD read occurring, then how often would software installed from a CD fail to operate becuase what was on the hard drive did not match what was on the CD? Note that I'm not talking about corrected errors. In all the years I've spent installing software from CDs (assuming the CD was not damaged in some way) I have never had that happen. Not once. Ever.
I guess all I'm saying is that there is a way to generate a data source that (if done correcetly) will allow the service of that data to be as accurate as what is on the audio CD, in a way that removes jitter from the serving component. At this point the REST of the chain will determine how that data will sound. And in that respect I agree with you completely. |
Alex/Aplhifi,
Thanks for providing some corrections & more info on the VRDS-NEO transports. I also believe that NEO is used as a dual purpose: one, as in NEO = new & second, because TEAC uses NEOdymium magnets now.
IMHO, Lktanx posts, your posts & my posts are ALL in agreement - you are saying the same thing! I think that your posts have played remarkably well into our hands!
>> In conclusion, it is a real fun for me to read all
>> these "error free" discussions, but at the end of the
>> day, there are many other VERY important things when it
>> comes to digital audio other than "Zero" error.
Alex, this is exactly what we are saying! The transport is very important for reading the data off the CD, ensuring that the final result is actually or practically error-free. Once this is ensured, the sound of the CD/DVD player is determined by "many other VERY important things". It is hardly dependent on the CD transport at that point.
>> I am sure that one day soon you will realize
>> that error free and bit perfect copy doesnt really
>> mean anything when it comes to digital audio sound
>> quality.
This is exactly what we are trying to emphasize as well, Alex!!
You are saying the same thing as we are, just using diff words.
Neither Lktanx nor I are belittling the importance of transports. However, what we are saying that they are means to an end (I wrote this in my orig post above). Once the final data is error-free (whether it is actually error-free when it gets read OR it is error-free after C1, C2 correction is IMMATERIAL to the DAC. I.E. the DAC does NOT care!) the sound of the re-produced music is dependent on "many other VERY important things when it comes to digital audio other than "Zero" error".
>> So my question to you is why then those error and
>> jitter "Free" digital players will not sound as good
>> compared to even a 15 years old regular CD player when
>> used as a digital TRANSPORT ONLY.
You know the answer to this, Alex! It is because there are "many other VERY important things when it comes to digital audio other than "Zero" error". It these other things (digital & analog power supplies, jitter, rise/fall edges, type of PCB material, DAC master clock, etc) that are severely lacking in these el-cheapo players 'cuz they are made to sell at a low selling price. It is not the 1/0 data read off by the cheap transport. If you want to blame the cheap transport then the blame should be levied on its cheap power supply that gets corrupted w/ the spiky read currents from the optical section & goes on to pollute ckts connected to this & other power supplies. IMO, this aspect belongs to the "other aspects" that you wrote about.
>> This is what I meant when I said that there are many
>> other important things other than a fake "error free"
>> digital data output.
>> Given the CD surface is really perfect, with the
>> Esoteric VRDS-NEO transport the error is REALLY Zero,
>> not only that, but the EFM signal jitter is also MUCH
>> lower than anything else currently available
whether it is "fake" or truely error-free, when the data gets to the DAC S&H, it DOES NOT matter & the DAC does not care. Error-free is error-free!
At this point the reproduced sound will depend more heavily on the DAC master clock jitter, analog & digital power supplies, linearity of the analog output stage(s), etc.
Also, in one of the above statements, you are addressing "jitter". Ah-uh, cannot do that, Alex! Jitter belongs to the "many other VERY important things" category you wrote about in your post!
What we are talking about here is the transport, the data read, the error correction(s) & the final data presented to the DAC.
>> Also, when you were talking about your friends
>> computer based audio with external DAC did you try your
>> Wadia as a digital transport through the same external
>> DAC?
I'm afraid that we did not! If I remember correctly we had a cable interface issue. At that time, we compared the Wadia integrated vs. his PC-based system.
>> Why don't you get one of these and hook it up to an
>> external DAC together with your x1 reading and non-
>> memory buffering VRDS Wadia and see which one will
>> sound better?
I am very close to doing this - I had to order a BNC to RCA adapter so that I could convert the output on the Wadia rear panel so that could use my digital cable. This will allow me to compare the Wadia transport against my stock Sony DVP-S7000. I'll keep you posted.
In the meanwhile I have been comparing my Wadia used as an integrated player w/ my stock Sony DVP-S7000 + Scott Nixon Saru DAC+.
Just like Tonyptony wrote: the Sony DVP-S7000 + Scott Nixon Saru DAC+ is SCARY close in sound to the Wadia integrated player. The cost of these 2 combinations is 32:1 with the Wadia being 32X more expensive! is my Wadia 32X better? Does it give 32X better bass & hi freq reproduced sound? NO SIR, IT DOES NOT! If the Wadia gave 1X better performance, it would 100% better, correct? I don't think that I could even say that! The Wadia is better, NO DOUBT, but marginally. The margin is significant enough that 1 listen will make it very apparent. If you listen to the DVP-S7000 + Saru DAC+ combination, there is hardly anyway that you could fault its performance. It is extremely musical. It is only when you pit it against a Wadia that the faults get highlighted. IMHO, the (little) David has given the Goliath a damn good run for its money. I wonder how close this "race" will get if I send my DVP-S7000 to Steve Nugent @ Empirical for mods? Hmmmm..... an $800 + shipping question.
|
Tonyptony and Lktanx, every CD player, even the cheapest one, has C1 and C2 CIRC error correctors which have certain ability to "correct" the error. If the error exceeds the capacity of the C1 and C2 THEN you have an Error Flag output. So, if there is no error flag, this does not meant that there is no error; it means that C1 and C2 were able to correct the errors. Also, please be aware that there are also error correction errors which mean that C1 and C2 sometimes will "correct" something that did not need to be corrected. The other VERY important factor is the EFM Jitter, for example, if two different CD drives have the same error correction engines which will ALWAYS report Error free output, the one that has less EFM jitter will sound better.
In the case of my example in my previous post I meant not using the Wadia as a stand alone unit, but A-B testing it against the computer based "transport" through the same EXTERNAL DAC. In this case, digital filters, DACs and Analog stages will not be the cause of the difference.
My point was also that even a $150 universal digital player uses VERY powerful error correction and memory buffering using large 64Mb (and some times 128M and 256M) memory chips which completely "remove" error and jitter from the reader similar to what can be done with a computer based digital. So my question to you is why then those error and jitter "Free" digital players will not sound as good compared to even a 15 years old regular CD player when used as a digital TRANSPORT ONLY. I am not talking about stand alone use.
This is what I meant when I said that there are many other important things other than a fake "error free" digital data output.
Given the CD surface is really perfect, with the Esoteric VRDS-NEO transport the error is REALLY Zero, not only that, but the EFM signal jitter is also MUCH lower than anything else currently available.
I am sure that one day soon you will realize that error free and bit perfect copy doesnt really mean anything when it comes to digital audio sound quality.
Regards,
Alex |
---------------
Any current $150 universal player uses powerful DSP and memory buffering which according to your and Lktanx theory is sufficient to do the job providing error and jitter free data output. Why don't you get one of these and hook it up to an external DAC together with your x1 reading and non-memory buffering VRDS Wadia and see which one will sound better? I can tell you right now; your Wadia will be a LOT better. Also, when you were talking about your friends computer based audio with external DAC did you try your Wadia as a digital transport through the same external DAC? If you have not, please do that and let us know if the computer based error free transport can provide the same bass extension and the same top octaves clarity, air, openness and resolution as your Wadia will.
----------------------
Alex,
I am only discussing transports and their associated error correction circuitry. Let's not compare different issues. Of course a Wadia will sound different than a PC playing a CD. This difference is not and should not be due to the transport and error correction. This is because both the Wadia and the PC possess transports/error correction circuitry which produce ZERO errors.
The Wadia sounds different because it has a different clock reference with different jitter characteristics. The Wadia also has different digital filters and DAC. So obviously they should sound different. Nevertheless, I will not state which sounds better.
I am not claiming that all CD players sound alike. I am claiming that a properly designed CD player's sound should be completely uncorrelated with the transport. The sound will be a function of the following (not in any order of importance):
1. Digital filters
2. DAC
3. Clock reference
4. Clean analog power supply
5. Output driver stage of DAC
Note, the transport/error correction circuit is one thing engineers can do perfectly, inexpensively, repeatably, and in large quantities.
I am purely speculating on the actual numbers but here is an example:
High end transport = 1 error per minute
Cheapo transport = 100 errors per minute
Obviously the high end trasnport is better here. Now with error correction:
High end trasnport with EC = 0 errors per minute
Cheapo transport with EC = 0 errors per minute
I hope this helps you decide where to invest your hard earned $. |
"Also, even though with computer based audio certain "error free" software can be used, this does not exactly mean that there are no transport device READ errors."
Alex, if one uses (and correctly sets up) Exact Audio Copy (EAC) along with a good CD-ROM drive that supports both C1 and C2 error correction (a Plextor Premium or similar) then you *will* get bit perfect copies, as long as there is nothing inherently wrong with the disk. If there is, EAC will give you an indication each and every time an error is detected. Any scenario which would cause a read error that was not detected by this set up (I'm not really sure that's possible) would neither be detected by a dedicated transport.
Having said all that, I agree with you completely that a bit perfect audio image is only part of the picture. But the tradeoffs between a server based bit perfect image and a fine transport are smaller than the D/A conversion of either of these signals, IMO. I've just recently moved to a server based world (a Squeezebox into my D/A converter), and guess what? That does not sound quite as good as my transport (a Proceed PDT3) into the same converter. Is it comparable to some of the other transports I've tried over the years? Yes. Is it scary close to what I have now? I'm afraid to say, yes, with the deficiency being (I believe) in the Squeezebox, and not in the server based delivery of a bit perfect signal. |
Bombaywalla, ALL CD/DVD/SACD players have a sled with linear tracking for the Laser, except for the famous Philips "swing arm" transport which is now obsolete. The big VRDS-NEO and some newer Philips transports are using a combination between radial and linear tracking where the focusing lens is "suspended" on magnetic field. Since this type of suspension is inertia-free, it is the fastest and most accurate reading technique available.
You CAN NOT prevent the disc from wobble, especially with higher than x1 rotation speeds when SDRAM buffering is used, without having a FULL disk support on the top (or bottom in the case of Pioneer "Stable Platter" system). With the Audio Desk Systeme Lathe you're talking about, you can balance the disc and prevent from vibrations caused by eccentricity, but NOT wobbling.
From what I know, the Esoteric VRDS you have in your Wadia spins at x1. The VRDS-NEO spins at about x10 using a large SDRAM buffer from which the data is clocked out. This allows the Laser to go back 10 times and re-read the data should there is error sensed by the DSP. Also, the VRDS-NEO is the ONLY transport currently available which is NOT suspended in any way. Still, even at this very high rotation speed, there is NO vibration you can sense. The READ error rate of the VRDS-NEO is almost 0 (if not 0) but Esoteric still uses the latest Digital Signal Processing with the most powerful error correction AND memory buffering in order to make sure that the error and jitter are indeed ZERO. There is no other disc spinning device (including CD/DVD-ROM) to offer these qualities.
Also, even though with computer based audio certain "error free" software can be used, this does not exactly mean that there are no transport device READ errors.
Any current $150 universal player uses powerful DSP and memory buffering which according to your and Lktanx theory is sufficient to do the job providing error and jitter free data output. Why don't you get one of these and hook it up to an external DAC together with your x1 reading and non-memory buffering VRDS Wadia and see which one will sound better? I can tell you right now; your Wadia will be a LOT better. Also, when you were talking about your friends computer based audio with external DAC did you try your Wadia as a digital transport through the same external DAC? If you have not, please do that and let us know if the computer based error free transport can provide the same bass extension and the same top octaves clarity, air, openness and resolution as your Wadia will.
In conclusion, it is a real fun for me to read all these "error free" discussions, but at the end of the day, there are many other VERY important things when it comes to digital audio other than "Zero" error.
Regards,
Alex |
Germanboxers,
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So, you are saying that mis-reading a "0" for a "1" or vice-versa with some random frequency will cause the sound to become like a blender? It won't just misrepresent the amplitude value of the complex wave at those particular sampling points? Assuming a .1% error rate, that's still 40 some errors in amplitude resolution/sec.
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It is due to the way PCM is encoded. Once again do not think of this as an analog signal. For CDs you have data which is 16 bits long. If any of the LSBs (least Significant Bits) were transfered in error, then you would probably not notice this. But as you mentioned since this is random, any of the 16 bits could be transfered in error. If any of the bits which did not reside among the lesser significant bits were corrupted the amplitude error would be huge. Yes, it would actually sound worse than a blender. Just think of what happens if one iota of a note went from very soft to very loud almost instantaneously.
Fortunately, this never happens for a properly designed player. Because there should be ZERO errors after error correction. Like I said, if your transport is failing, you will know it. It is not subtle. |
Jordan/Germanboxers,
it appears that you have not spent much time in thinking about the CD transport stuff. When you write your posts, you seem to be writing ex-tempo & there does not seem to be much depth. you are also blowing the importance of the transport -w-a-y- out of proportion, if I may say so. Transports are very important but they are a means to an end. The end being to get the data read reliably & as quickly as possible. Spend some time & research the matter.
Lktanx has understood the subject matter exactly!
>> The question that neither of us can answer conclusively
>> is to what degree does a transport that exhibits less
>> random errors have on the final sound quality?
I can't remember exactly when this was (maybe it was in grad school) but I remember spinning a CD that had holes drilled in it. NOT THROUGH HOLES; rather, holes drilled deep enough where they encroached into the recording material. These holes were made in the N-S-E-W directions so it looked like an equal-legged cross. Also, the holes were NOT made in the TOC area just so that the CD player would actually play the CD. The objective of this was to demonstrate to us the robustness of the error correction. So, obviously the disk had to play! There was an exact 2nd copy of this disk that was pristine (like the one you'd get from a store). How did it sound? For all practical purposes it sounded just like the pristine copy.
So, what does this tell us? If there are certain # of errors while reading a disk, the error correction system can neutralize them & the sound of the reproduced music will be practically unchanged to the user listening. If the # of errors increases to the point that it overloads the error correction system, then, the sound will be degraded & will "It will sound someone turned on the juice blender for a brief period".
The CD error correction has an enormous appetite for errors & it takes a significant # of errors to break it. Randon errors are just that - random! They do NOT occur at a high enough rate to overload the disk error correction algorithms. Just as Lktanx wrote, if you have a unit that does create a high rate of random errors, you have a defective unit & the transport needs to be repaired/replaced.
>> Again, I don't offer this as conclusive proof, but why
>> would a company such as Esoteric spend mucho $ on
>> developing and manufacturing a massively overbuilt (by
>> an order of magnitude in weight alone) transport when
>> the machines they are placing them in also buffer the
>> data to SRAM?
there are many aspects in the design of a transport. what distinguishes a good one from an average one is: (1) the disk clamping system. A CD spins at 200-560RPM (most of the time, I've read 360RPM). The edges of CDs are not perfectly smooth or straight. Hence, at that speed, if the CD is clamped only in the middle, the CD will wobble. In effect it becomes akin to reading a newspaper placed on your lap in a subway train! In the transport there are surges in electrical current drawn from the digital supply by the laser optics electronics. This has the effect of dirtying the digital power supply & this crud pollutes everything it touches. Also, as the disk wobbles, the laser beam becomes unfocused. An unfocused beam can make errors reading data. So, TEAC's VRDS system was designed to clamp the ENTIRE disk. Does this come for free? NO! it adds weight to the whole transport but it is 1 possible solution to preventing the disk from wobbling. a 2nd solution is available too - a CD cutter w/ a fine edged knife. I believe that it cuts 200 CDs before the blade needs replacing. Solves the same issue by having the user spend less money than buying a TEAC VRDS system. (2) the laser system in an average CD transport has to tilt or rotate so that it can read the entire CD surface. This has the bad habit of spreading the laser beam. this is said to increase jitter & also possibly cause read errors. So, what TEAC does in its VRDS & VRDS NEO systems it that it has the laser pickup on a sled. This pickup operates just like a linear-tracking tonearm on a TT. However, this sled has to be stable. Does this come for free? NO! it adds additional mass to the transport. Plus, it needs a motor & a clean power supply, which add further weight to the system.
I believe that TEACs solution is one manuf solution to these problems & I believe that they have kept the overall transport system as simple as possible but NO SIMPLER. This, of course, does NOT mean that their solution is simple; rather, it is only as complex as it needs to be. If you look at one of their VRDS transports, it is one serious work of art & engineering - I have SE transport in my Wadia.
There is one other factor that is part of the Japanese culture (that an American consumer will probably not understand): the Japanese are favourably disposed to over-engineering. It is in their products since the 1970s. Look at old Sony Walkmans, Sony TVs, etc: they look beautiful inside just as they do outside.
What I'm saying is that there is some element of over-engineering in the TEAC VRDS transports. However, the Japs take it in their stride as they have their home market in mind 1st. The fact that Wadia, the only American company AFAIK, uses it as well is just some side business for them.
there is 3rd aspect that plays superbly into the American manuf's hands: the US audiophile LOVES heavy weight audio gear! If it's heavy, it must be good! To that effect, name 1 European CD player manuf using the TEAC VRDS transport?
Once again as Lktanx wrote, computer-based audio has come a very long way in catching up w/ CD transports. The CD/DVD drives in today's computers are superbly robust & when they get done reading the data from the CD, it is practically 100% correct. CD/DVD drives have always been built with on-board SRAM & they have always been accompanied by hi-speed buses (IDE or SCSI in former years & USB 2.0 today) to carry the data to the CPU. This plays superbly into the hands of a PC being used as a transport for audiophile grade sonic quality.
I have personally pitted my 861 against the my friend's higher-end PC which he uses as a transport into a Scott Nixon Tube DAC+. His floor-stander PC uses a gaming chassis so it has a fancy blue flashing light, it uses higher speed hard-drives & a Lynx sound card. It was self-assembled & probably costs $2000-$3000, which is less than half the cost of my Wadia! Sonically, the difference is even less than the cost disparity. I love my Wadia & I won't part w/ it but it would be utterly foolish of me to ignore the "threat" PC audio is giving TEAC VRDS transports. You can ignore it but at your own peril.
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So, you are saying that mis-reading a "0" for a "1" or vice-versa with some random frequency will cause the sound to become like a blender? It won't just misrepresent the amplitude value of the complex wave at those particular sampling points? Assuming a .1% error rate, that's still 40 some errors in amplitude resolution/sec.
Again, I don't offer this as conclusive proof, but why would a company such as Esoteric spend mucho $ on developing and manufacturing a massively overbuilt (by an order of magnitude in weight alone) transport when the machines they are placing them in also buffer the data to SRAM? I don't think it's reasonable to attribute this decision to marketing bs...way too expensive without meaninful return for that.
Jordan |
Germanboxers,
Yes, the 1's and 0's are represented with voltages. But unlike an analog system where any slight deviation is considered distortion, the digital system is orders of magnitude more impervious to signal variation. Here is an example.
Consider a typical system where 0V represent a "0" and 3V represent a "1". For a "1" to be mistaken as a "0" the 3V will have to drop below 1.5V. In the analog circuit case any variation is bad but for the digital case the signal has to lose half it's value before a mistake is made.
Another way to think about this is that in an analog amplifier, the designers have to make sure that distortion is below say 0.1%. But for a digital system, you can tolerate up to 50% signal change (i.e. 3V dropping to 1.5V) before one error is made. Furthermore if an error is made, the use of error correction fixes this issue.
I can say for certain that the data read from a transport after error correction will be ZERO (unless you're thumping the player with a hammer). If this is not the case you have a defective unit and you should get it replaced. Furthermore, if your defective unit is producing bit errors, you will definately hear it. It will not sound like "the soundstage of the music has narrowed". It will sound someone turned on the juice blender for a brief period.
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Lktanx, you do understand that a digital bitstream is just a voltage (analog) approximation of a series of square waves representing the "1" and "0"'s? It's not just mathematics.
I was not referring to massive errors resulting in skips, etc. What I was referring to was the fact that all physical systems exibit some degree of random variation (random error for sampling systems) and these non-correlated errors cannot be "corrected". The question that neither of us can answer conclusively is to what degree does a transport that exhibits less random errors have on the final sound quality?
Ram buffering makes a great deal of sense...on that we agree completely!! Why do you suppose a company like Esoteric has gone through the trouble and expense of developing an incredibly massive and robust transport (VRDS Neo) for exclusive use in players that also SRAM buffer the data? I certainly wouldn't offer this as "proof", but it is interesting that over half the cost in their machines is taken up by the transport mechanism...and all of them read the data to SRAM. It would be interesting to be able to take two of their machines, pull the VRDS Neo out of one, stick a CD-ROM transport in it, and compare the sound side by side.
Anyway, interesting discussion. As an engineer, I'm somewhat baffled at times by what can make apparently meaningful changes in the sound I hear. I'm equally baffled by some of the absolute crazy stuff being peddled by some as well. |
Germanboxers, I would like to emphasize that you are right; the transport is very important. It is responsible for getting the data correct. However, getting the data correct is very easy and very inexpensive and very trivial. All PCs today rely heavily on CD/DVD transports doing their job well. In a PC, when a transport fails, you throw it in the trash and get a new one. |
Transports are not perfect i.e once in a while they make errors but these errors are detected and corrected by a digital circuit. If the system makes a huge amount of errors, such as when your car CD player skips when you drive thru a bump on the road, then you will hear this. A skipping CD player is an example when too many errors are made which "overloads" the error correcting capability of the circuits.
Note that we a talking about a digital means of data delivery. This is not an analog system like a turntable where subtle issues i.e. spin rate of the turntable can be coupled into the music. The digital system with transport is tranferring 1's and 0's into RAM. It does this with the utmost reliability. Dont forget you are trusting such a system of data transfer when you use your computer on a daily basis. |
As you know any computer today can play a CD/DVD. But a CD/DVD player does not have to be as complex as a computer. A CD/DVD player does not require an operating system. However, it does have firmware, i.e. software which runs the hardware. Dont forget that all CD/DVD players are digital systems anyway so they already have RAM memory. If properly designed, a CD/DVD player can offload all data into RAM prior to playing the music hence relegating the responsibility of the transport to merely a temporary storage for the music. Furthermore once the data has been offloaded into the RAM buffer, the transport no longer has an effect on the quality of music. Just think of the CD/DVD disc as inexpensive storage and the transport as a means of transfering the data on the CD/DVD to digital circuits. You can decouple the processing from the storage (the disc) by using a RAM buffer for intermediate storage. |
the idea of a computer as a transport is intriging however, there are too many variables right now (os, software, hard drive integrity etc....)
a minimist approach with a buffered transport or dac is very, very attractive...
are there any ram buffers (not clocks) that can be added to exsisting transport or dac's ? |
Lktanx, so if error correction is only for gross errors, then it seems logical that the transport becomes a very important part of getting the data correct, particularly if it can minimize the random errors that occur in all physical systems. If errors are correlated, then adaptive error correction would be helpful, but how are random errors corrected once they occur?
I agree that once the data is read to RAM, the only meaningful influence on the digital signal, other than digital filtering and D/A conversion, is the precision of the clock. Still, to get the data into RAM you need to read it via a transport, and unless you're claiming that all transports are perfect, I don't see how the transport is not a meaningful link? We could debate the significance of this link, but that's another issue altogether. |
I´d like to add another one Barclay X-1 |
thanks for the info...i wasnt aware the universals did this (this sparked my interest, i remember the chord dac64 & the tube technology fusion)...
were there any other devices (internal or external) are available beside the genesis lens ? |
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Questions are: 1.) is adaptive error correction good enough. 2.) what influence does mechanical vibration have on (1.) and on the overall performance of the player/transport. I wish I could answer these... I cannot, but I too have heard significant and very meaningful differences among transports.
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Answers:
1. Error correction is designed to fix bit errors. These are gross errors. Ever drive your car thru a bump and your CD player skips? Error correction is designed (together with buffering) to fix these types of problems. If you plan to listen to your music while thumping the player with a hammer, then I would be concerned about how good the error correction is.
2. Mechanical vibration is answered in (1) above.
The transport has no effect on the signal data if it is read out to a storage device such as RAM prior to further processing.
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I am not referring to any specific CD/DVD player. In our hypothetical CD/DVD player, the entire song can be uploaded to RAM (i.e. computer memory). This is very inexpensive. Once the song is in RAM which is a digital circuit, it can be read out and processed by the other digital circuits of the CD/DVD player. These circuits perform error correction decoding and filtering. These are typical circuits in any CD/DVD player.
The key point here is that once the song has been uploaded to RAM, the transport is no longer part of the signal path. It is effectively non-existent. You can think of an Ipod Nano as a CD/DVD player which has the song loaded into RAM. Of course the loading of this data is performed from a PC and not a transport.
Once the digital signal has been processed by the digital circuits, this signal has to pass thru a D/A converter. The quality of the D/A converter as well as the clock which clocks the D/A converter can effect the sound quality. If the clock is sufficiently jittery, you will hear this.
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Mike, I believe Lktak is referring to what nearly all Universal players use. Models like the Denon 3910 and many other Universal players read at something like 10x rate and buffer to SRAM, then reclock out. Some carry this buffering to redbook CD as well. In theory, if your error correction software is infallible and your reclocking extremely precise, this should result in a perfect bitstream. Questions are: 1.) is adaptive error correction good enough. 2.) what influence does mechanical vibration have on (1.) and on the overall performance of the player/transport. I wish I could answer these... I cannot, but I too have heard significant and very meaningful differences among transports. |
Lktak, what type of ram devices are there beside a genesis digital lense (or I am misunderstanding the concept)?
could be be more specific on what RAM you are referring too (can it be added to transports ?)
thanks !! |
In a modern properly designed player, transports should make no difference to the sound. Here is an example of why this is the case:
Take any cheapo transport for $10, read the data from the CD/DVD/SACD into RAM. Use the cleanest possible clock reference and read the data from this RAM for further processing. Hence you get perfect data with the cleanest possible clock.
An Ipod Nano has this type of "transport" or non-transport. Of course other design elements of the Nano makes it non-reference such as the compression of the data and the inexpensive output processing. But it does have a perfect "transport".
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Tmhaudio: Of course...I was just citing a general tendency, nothing more and it was more of a casual observation not a statement per se. I actually did listen to a Metronome CD player (one box) last year and found it excellent indeed. So the higher set up which you describe should certainly be excellent as well I would imagine. |
Henryhk:
Yes, lots of great transports/DACS originate from Japan. But as the NA distributor of the French Metronome, I must state the T2-i Sig is a world Class-A transport/DAC in 2 chassis. The even more stunning 2-chassis Kalista transport (in sound & aesthetics) w/separate Power Supply was recently compared to vinyl in 6moons.com review - perhaps the highest compliment one could receive to achieve analog purity & resolution. |
I've heard that the current problem with CD transports is that one or two companies have a monopoly on the production of the requisite laser mechanisms, which are poorly made and have a high rate of failure. Due to this lack of options even the best gear ends up having to employ cheap lasers. Furthermore, the manufacturer changes the laser design every year. Therefore, someone building a transport needs to buy a huge backstock of the lasers all at once in order to be able to offer a warrantee service, and also factor in the cost and problems associated with repairing many failed units.
Is there someone knowledgeable who can comment on this? |
