phn said:
I'm getting a bit confused???
Dishonest? I'm even more confused???
Logical error? Well no. Its not a question of disproving something that cant be challenged through experiment such as the existance of a diety,
The question of if read errors occur or not is pretty easy to measure. If you know the values of the data, and you can measure how much of it is read, then you can say pretty definately wether its been read correctly or not. Even simpler. If you can take the results from a standard transport, then add a weight to it then measure again, and then compare the data... You can tell wether adding the weight changed the data that was read. Might not tell you wether one is better or worse than the other, thats to a degree subjective, thats what we use ears for, but it will tell you if theres a difference.
I'm not suggesting that you do it yourself, just link to someone who has... I'll give you a clue, check out your much hated stereophile online magazines. The artical I read either failed to link disk error to several cd tweaks. They measured and found no link. Shame I cant find the link either (geddit)
Incidently when I modded my Mission 753 tweeters, I used a similar slapdash methology to test wether the mod had made a difference.
I tested with and without the tweeter mod done using a decent quality mic into a medium quality soundcard. Got no results that could be declared a measure of quality, but I did get sufficiently different results so that I could say the sound signature had changed. Then it came down to my preference. The mod stayed.
justblair said:
Getting? You are the ones claiming error is a problem. I have claimed nothing.
To be more precise. You say error is a problem. And increasing inertia will solve the problem.
Before trying to solve the problem, shouldn't you first make sure there is a problem?
In more than 100 posts we have seen nothing that supports the claim that errors are a problem. All we have so far is assumptions.
justblair said:
It's dishonest because I have never made any claim. If reading errors had been a problem, I'm sure we would have heard about it. So I'm not going to set out to prove something that from what I can gather is not a problem.
Em no...
I never claimed it was a problem... But that read errors occur. I also took some time to provide links that support this.
I didn't say specifically that adding inertia cured this.... Only that it may make an improvement, I wasn't ruling it out.
And dishonest?
dis·hon·est (ds-nst)
adj.
1. Disposed to lie, cheat, defraud, or deceive.
2. Resulting from or marked by a lack of honesty.
You asked someone to look up logical phalacy, I saved you the bother on dishonest....
I dont see how asking you to provide some evidence to support your position comes under either of those definitions... In fact its quite a rude accusation to make.
I have an open mind to this whole issue, I am interested in learning more, not because I use a cd player, but more out of curiousity. I am listening to your points as well as the points of others. Trouble is that your arguements are not convincing me as they lack any evidence. Its easy to say that anything like this is rubbish, you may even be right, but without making any attempt to demonstrate your point, why should I accept your viewpoint as being gospel over others in the thread who at least give examples of their own experiance. Quite frankly I am more disposed to listen to those that treat the others in the tread with a modicum of respect.
As I said before, the only real way to know if adding inertia makes any difference to sound quality is to try it and see. I suggested that a few posts before and i still think its the only way of knowing . After that the arguement can be over why it does work or it will die if indeed it is hokum. Either way everyone will have learned something.
I never claimed it was a problem... But that read errors occur. I also took some time to provide links that support this.
I didn't say specifically that adding inertia cured this.... Only that it may make an improvement, I wasn't ruling it out.
And dishonest?
dis·hon·est (ds-nst)
adj.
1. Disposed to lie, cheat, defraud, or deceive.
2. Resulting from or marked by a lack of honesty.
You asked someone to look up logical phalacy, I saved you the bother on dishonest....
I dont see how asking you to provide some evidence to support your position comes under either of those definitions... In fact its quite a rude accusation to make.
I have an open mind to this whole issue, I am interested in learning more, not because I use a cd player, but more out of curiousity. I am listening to your points as well as the points of others. Trouble is that your arguements are not convincing me as they lack any evidence. Its easy to say that anything like this is rubbish, you may even be right, but without making any attempt to demonstrate your point, why should I accept your viewpoint as being gospel over others in the thread who at least give examples of their own experiance. Quite frankly I am more disposed to listen to those that treat the others in the tread with a modicum of respect.
As I said before, the only real way to know if adding inertia makes any difference to sound quality is to try it and see. I suggested that a few posts before and i still think its the only way of knowing . After that the arguement can be over why it does work or it will die if indeed it is hokum. Either way everyone will have learned something.
phn said:
Not quite...
WE accept that read errors occur !
WE accept that read error correction techniques employed reduce the effect of any errors to virtually nil in most cases.
The original question was :- Can increasing the inertia of the CD platter reduce the number of read errors ?
Andy
Hi Phn,
Do you really believe it is possible to read all the data? Not read in error and have corrected, but read the data faultlessly?
As an engineer, I never have 100% confidence in an object that I am working with. That would be foolhardy, and costly when proven wrong (no doubt it will be proven wrong by a pesky customer, which is never funny).
I fully agree that misreads may well not matter, but I didn't realise that was the point of the debate.
And I'm very sorry to hear about your Volvo driving friend.
Cheers,
Phil
I think myself and others have agreed that increasing inertia is pointless. I've said this a few times before - but I'm just full of it.
Do you really believe it is possible to read all the data? Not read in error and have corrected, but read the data faultlessly?
As an engineer, I never have 100% confidence in an object that I am working with. That would be foolhardy, and costly when proven wrong (no doubt it will be proven wrong by a pesky customer, which is never funny).
I fully agree that misreads may well not matter, but I didn't realise that was the point of the debate.
And I'm very sorry to hear about your Volvo driving friend.
Cheers,
Phil
Hi Tubee,
I haven't read the data sheet, but you'll probably just see a full RAM with changing values. As RAM gets emptied (if its not a circular buffer) it doesn't get cleared to zeroes. Just like, when you delete a file on an HDD, the data stays there, but the OS just allows the space to be reused when required. It would cost time to clear it out - which would only be for human convenience.
So, you're right, not easily measurable.
Cheers,
Phil
I haven't read the data sheet, but you'll probably just see a full RAM with changing values. As RAM gets emptied (if its not a circular buffer) it doesn't get cleared to zeroes. Just like, when you delete a file on an HDD, the data stays there, but the OS just allows the space to be reused when required. It would cost time to clear it out - which would only be for human convenience.
So, you're right, not easily measurable.
Cheers,
Phil
Maybe someone has already suggested it, but most CD transports have on one of the decoder IC's an "error flag" that flags a read error that is then 100% corrected by the error correction circuitry.
One could connect it to a simple counter and just count the numbers of errors when playing as-is, and then again with weight added to the platter. This should give some objective information and is very easy to do and replicate.
There has been an Elektor design for such a counter but any old freq counter could be used. Incidently, the Elektor article mentioned that on average CDs the number of read (and corrected) errors numbered many thousands per CD. And of course the comparison should be done with the same CD.
BTW, I expect that you will find that the differences between CDs is much, much larger than any difference caused by the platter weight, if any. But that's just my opinion and it should be tried.
Jan Didden
One could connect it to a simple counter and just count the numbers of errors when playing as-is, and then again with weight added to the platter. This should give some objective information and is very easy to do and replicate.
There has been an Elektor design for such a counter but any old freq counter could be used. Incidently, the Elektor article mentioned that on average CDs the number of read (and corrected) errors numbered many thousands per CD. And of course the comparison should be done with the same CD.
BTW, I expect that you will find that the differences between CDs is much, much larger than any difference caused by the platter weight, if any. But that's just my opinion and it should be tried.
Jan Didden
I just don't get it: what's all this obsession with the read errors? Yes, there are non-recoverable read errors but this is generally a non-issue in most cases.
Comparisons between EAC extracted and CD-transport generated files show they are practically identical.
If transports sound different it's always due to jitter and getting the damn spdif interface working right.
Comparisons between EAC extracted and CD-transport generated files show they are practically identical.
If transports sound different it's always due to jitter and getting the damn spdif interface working right.
poynton said:
We haven't yet established that errors occur. Only that they can occur.
poynton said:
Yes, I should have written "hopefully." I got goaded back.
philpoole said:
The inertia per se isn't important. It's the idea that something is wrong and needs to be fixed.
philpoole said:
I believe nothing. That's basically the core of what I have been repeated here. YOU believe.
The Volvo story was made up. The story was to illustrate the logical errors of some posters. In my case the logical error is the conclusion that Volvos are unsafe cars because a friend of mine died driving one.
Edit: Jan says the errors number in the thousands. Now we have a start.
analog_sa said:
They ARE identical. I have a few friends who actually did check this (Netlist was one of them). They repeatedly wrote CD-ROMs and ripped them comparing the results before-after. They were BIT-IDENTICAL. Cheap PC CD ROM drives. Point is, unless you have gross unrecoverable errors, the copies and reads are bit-perfect.
Think about it: MS ditributes 50MB+ application programs on CD ROM and they install and run perfect each time. Audio requirements are trivial compared to this.
Jan Didden
I think we/some/whomever may be barking up the wrong tree. I suspect a lot of the effect a transport mechanism may have on sonics has to do with how it interacts with other subsystems.
I suspect a lot of evil comes from PSU interactions, the beter the mechanics, the less corrections and focussing etc is needed (same goes for the disc I would think) and the less varying demand is made on the PSUs of a player. This I beleive is why providing better power supply isolation from other parts of the player provides gains.
So, I think errors may be less audible then some suspect per se but their secondary effect is perhaps more audible?
This could also be checked with a scope, by checking action on the powersupply rails while different discs are played. Perhaps 2 identically made CDRs with one "treated" with a copper polish or other abbrasive and one nice and shiny...
I suspect a lot of evil comes from PSU interactions, the beter the mechanics, the less corrections and focussing etc is needed (same goes for the disc I would think) and the less varying demand is made on the PSUs of a player. This I beleive is why providing better power supply isolation from other parts of the player provides gains.
So, I think errors may be less audible then some suspect per se but their secondary effect is perhaps more audible?
This could also be checked with a scope, by checking action on the powersupply rails while different discs are played. Perhaps 2 identically made CDRs with one "treated" with a copper polish or other abbrasive and one nice and shiny...
Perhaps not just if the analogue is shared, even digital supplies may be negatively affected if shared.
For whatever reason, my CD9 Pro based Theta Data Basic sounds very different (and I think better) then most other players I have tried as a transport. There are around 10 or so regulators in that thing for different stages and when the clock circuit got its own transformer (the MKII upgrade) it sounded better again. Could just be SPDIF implementation but I think there is more to it.
I have tried some DVD players as well but did not like them much though none were the highly "internet" rated ones from Toshiba etc. Just a Sony and Pioneer basic stuff.
tubenut said:
tubenut
what decoder is your player using?
The error correction seems to be in the decoder itself, and by standards set,
But company's will take there own view on it and add or modify to suit there own tastes.
Maybe there is more to the decoder and/or it's implementation?
The saa7210's seem to reclock by internal PPL to 8.6436MHz and half clock (4.**MHz) of this for the incoming data.
No wonder clean volt's and reclocking helps.
But are we getting all the relevent pins?
As for the error light, I can see why not many implement this.............
Could you imagine a salesman explaining why the light is flashing
allan
janneman said:
Its A&T allright, have been searching an hour for it, no result.
Maybe it then looks like i have been talking out of my neck again because i cannot come up with any proof, but i personally don't care about that anymore. ((I believe nothing. That's basically the core of what I have been repeated here. YOU believe.))
----If you have a unit where supplies are used at the same time for the servo's and the analog output stages, noise, pulses etc caused by the tracking circuits can lead to (audible) effects on the analog circuits.----
I modded a CD304 mk2, and managed to reduce noise floor dramatic. With a headphone i could hear the servo taking to next track. After better decoupling of opamps it was gone (C-L+R-C filter) Opamp used same +/-12V as servo, the CD304 deserves a separate PS for I/V
I suspect a heavy CDM (CDM1) needs more current, and a flimsy and light CDM would show smaller current draws. But maybe i am talking out of my neck again...
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