So how do you make CD sound as good as vinyl?

[Duke Spinner]

Block Error Rate ....anyone ..??

[maxg]

Say what Mark???

I dont think I followed...er....much of that.

Suffice to say - if my platter it rotating happily at something around 33.3 and the power to the motor drops then the motor will start to act as a brake on the platter (which - in the case of the Project was something around 1.5 Kg from memory). The connection between platter and motor was a large rubber band. I guess you would get some compression of the band on one side and some stretching of the band on the other side of the motor's spindle. I do not know what time it would take for said rubber band to equalize back to its original evenly loaded state but I would not be surprised if the slowing of the motor a single time resulted in varying forces applying to the platter for an unknown period of time thereafter.

If we are dealing with a simple electric motor (which we are in the case of the Project again) then as the frequency from the mains (nominally 50Hz) varies back and forth I could see a fundamental frequency being established which would exaggerate the stretching and compressing of the band and in turn have an effect on the platter.

In the event that you have, as an example, Maria Callas holding a high note for a few seconds or more wavering in her voice can be caused as a result of a change in the speed of the rotation.

I think.

[Mallette]

Fully agree about the critical nature of platter rotational consistency. I've heard few tables where some degree of wavering could not be heard on sustained flute notes and such. A person of perfect pitch will be even more impacted...

Dave

[maxg]

Sorry for my lack of clarity, as to percent of what. I haven't done the math translated to LP, but what I really meant was 1/10 of a percent of the time of a recording. To make it easy, let's say a recording is 100 seconds long. 1% faster would take it to lasting 99 seconds in its entirety. My challenge would be that one could manipulate the pitch control of a device by just 1/10 of 1% many times during a listening session up or down and the listener couldn't tell.

Some material is easier to hear an unsteady pitch in than other material and of course some people are much better at discerning differences than others. I'm just skeptical that dead-steady pitch is the big factor in turntable quality. Also the speed of the transition is important, whether it is a painfully slow one or instantaneous.

Paul,

I am starting to get confused myself. One tenth on one percent on the speed is applicable to the rotational speed however you describe it. If the rotational speed is 33.3333 rpm then 1% is 0.333 rpm - which I maintain can be heard - and 0.1% is 0.0333 rpm which, if we are running fast would equate to an actual rotational speed of 33.3666 RPM. If we were running slow it would be 33.3 RPM.

Frankly even if we were discussing a plus or minus 0.1% rotational speed I do not know if I could detect it - I am not even sure I can measure it that accurately in the first place with the strobe setup disk. I do, however, know someone that almost certainly can. She is not an audiophile - she is a Musicologist and what those people can hear is staggering to behold - but even there is would require careful selection of music for testing.

[JJkizak]

I remember in the 60's and 70's Ampex saying they accidentally recorded the finest wow and flutter test tape in history at +-.03 %. At a cost of $300.00 for this 2 " tape it could be yours if you could find it. Of course that is the 1970 price.

JJK

[DrWho]

We could get into PC "error correction," but

that would, as it already does, confuse the heck out of everyone.

Suffice it to say that if so much as a single significant bit of your

program or OS is delivered differently from one time to the other, you

are going down... Computers are MOST unforgiving about such

things compared to ears.

I am one of those PC for music advocates, Cal.

We just got finished with the topic of error correction in one of

the classes I'm taking. The term is such a misnomer because people

unfamiliar with the concept make the assumption that errors are being

passed, which is NOT the case. With any decent CD player, the reading

of a disc IS 100% accurate. Take it from the people that know what

they're talking about...it is a complete non-issue with CD playback.

To further stress the point, let's look at what happens when a

single bit transferred incorrectly (and assuming no error correction is

being used to make it a simpler analogy). First of all, we must realize

that the data stored on a CD is not laid out in a linear format. It is

NOT like an LP in anyway. If we wanted to, we could just randomly place

the data all over the disk (as long as our machine somehow knows the

order of all the random locations). So to keep the analogy simple, a

short segment of time is recorded in a linear fashion, but is then

rearranged and laid down on the disc in blocks of memory. If just ONE

bit in that block is "incorrect" the reconstructed waveform will be

VERY DIFFERENT from the original. It's not like it's just off one

sample, it recreates an entirely new wave. The audibility of this is

huge and you would KNOW if this were the case. However, combined with

the "error correction" (which is just an alogorithm to ensure the data

is read correctly) a misread block is passed as silence instead of a

crazy waveform. And again the audibility of this is huge...do you ever

hear the sound just dropping out when you play a CD? I know I don't.

So what is jitter? Jitter is something that can ONLY happen during

the digital to analog conversion. To stress the point, everything that

stays in the digital domain is 100% perfect...there can be no losses in

quality whatsoever. It is mathmatically impossible. When the data is

read off the disk it is stored in a buffer, where the error correction

can take place and then the bits are rearranged into a linear format to

feed the DAC. For the DAC to function properly, it needs to have a time

source (a clock) and the recorded voltage that the analog waveform

should have (the data stored on your CD). However, it is ridiculously

difficult (pretty much impossible) to have them be seperate entities so

the clock source for the DAC is the data itself. As the buffer outputs

its digital signal to the DAC, there are sometimes very minor timing

errors that can occur. The basic idea is that each bit isn't arriving

to the DAC at precisely the same interval and therefore you have an

inconsistant clock. It is in this stage and this stage alone that

really determines the quality of any digital medium. How well can the

device send the signal with a consistant clock. And then how well can

the DAC reproduce the waveform?

Now I know I have way oversimplified the issue, but hopefully it

should make some sense. If you don't want to wrap your mind around the

issue then just trust the "experts" that digital formats are completely

lossless all the way up to the buffer driving the DAC.

On an interesting side note....the skip protection used in portable

players is really just a larger buffer than can store more memory at

once.

So when you jiggle the player and it loses it's tracking, it has plenty

of time to find its spot again and start reading off the disc before

the buffer runs out. In fact, the reason a skipping CD player repeats

itself over and over is because the buffer works on a cycle and it just

loops through the buffer playing back whatever is there. So if the

laser can't read the data off the disc, then it's not going to update

the information on the buffer and so the player outputs the same

information to the DAC until new data is read.

It really is a fascinating topic and if anyone wants to read up more

on it I would highly recommend reading some books. The only thing you

will really need to understand first are the concepts of binary math

and basic computer logic (which can be picked up in like a week of

reading).

Btw, I'm all for using the computer as a playback source too. There

is a reason that recording studios use it as their main medium too []

[sfogg]

"With any decent CD player, the reading of a disc IS 100% accurate."

That is very likely true as long as the CDs aren't damaged.

" Jitter is something that can ONLY happen during the digital to analog conversion."

Not true. Jitter can be an issue during S/PDIF transmission (if the transmitter misreads a bit from timing instability between the three clocks feeding the S/PDIF transmitter chip and the audio data that is jitter), same thing during reception, ditto feeding to a DSP.

However, if at the end of the chain the data has made it to the DAC properly none of the jitter ahead made a difference.

"To stress the point, everything that stays in the digital domain is 100% perfect...there can be no losses in quality whatsoever."

Also not true. Any type of processing of the signal in the digital domain can potentially degrade the signal too. That is why 16bit audio is processed at 24bit (or higher) resolution... to reduce rouding errors.

" However, it is ridiculously difficult (pretty much impossible) to have them be seperate entities so the clock source for the DAC is the data itself."

A PCM DAC is fed three different clocks (master clock, bit block, L/R clock) along with the audio data itself.

Read this thread:

http://forums.klipsch.com/forums/538960/ShowPost.aspx

And I explain (and show) how the clocks relate to how audio data is fed to the DAC.

Shawn

[LarryC]

So what is jitter? Jitter is something that can ONLY happen during the digital to analog conversion...For the DAC to function properly, it needs to have a time source (a clock) and the recorded voltage that the analog waveform should have (the data stored on your CD). However, it is ridiculously difficult (pretty much impossible) to have them be seperate entities so the clock source for the DAC is the data itself. As the buffer outputs its digital signal to the DAC, there are sometimes very minor timing errors that can occur. The basic idea is that each bit isn't arriving to the DAC at precisely the same interval and therefore you have an inconsistant clock. It is in this stage and this stage alone that really determines the quality of any digital medium. How well can the device send the signal with a consistant clock.

I mentioned a "clocklink" above (now, I don't really understand this, so some forgiveness, please).[:^)] Some players have what they call a master clock next to the DAC chips that sends a separate link back to the transport to control the disc speed and gives the DAC more accurate information on the timing of the signal from the transport. Does that sound somewhat right, and does it differ from what you describe?

Larry

[Petrol]

So how do you make CD sound as good as vinyl?

eh, turn it over and scratch the crap out of it? []

[maxg]

So how do you make CD sound as good as vinyl?

eh, turn it over and scratch the crap out of it? []

Now THAT'S funny

[Jimmy James]

With a title like this one you guys must really be bored OR you just like making Ms. Unger's life miserable.

Flames anyone?

[maxg]

Well Jimmy, you will notice we are on page 3 of this thread already and hardly so much as a spark thus far. You would be surprised what can and cannot be discussed on here - under any title - whilst the seemingly most mild comment can lauch a Jihad at the other end of the spectrum.

In the meantime if you follow the provided link - that title is very much the aim of the creator of this $24,000 CD transport.

[classichits]

After all is said and done. There is something about vinyl that cd will ever be able to

reproduce. If givin a choice of an album or cd from an artist. I would always choose

to by vinyl. I have about 500 albums and I will never depart with them.

[Jimmy James]

Well Jimmy, you will notice we are on page 3 of

this thread already and hardly so much as a spark thus far. You would

be surprised what can and cannot be discussed on here - under any title

- whilst the seemingly most mild comment can lauch a Jihad at the other

end of the spectrum.

In the meantime if you follow the provided link - that title is very much the aim of the creator of this $24,000 CD transport.

Point taken and accepted, EXCEPT for the fact that this is not the only

place where this worn out debate is popping up here, in the last day or

so. As you probably already know Max, I'm the guy that's looking

for the 2-channel forum, not the Chevy's better than Ford debating

society.

Try your navel, it's probably more interesting.

[mobile homeless]

As you probably already know Max, I'm the guy that's looking for the 2-channel forum, not the Chevy's better than Ford debating society.Try your navel, it's probably more interesting.

Speaking of navel, I would check your own to see if any lint is there from your sock....

kh

[Mallette]

Jimmy:
As a "medium timer" with 1400 or so posts, I've gotten to know who baits, bites, barks, or barfs. I hang almost exclusively in 2 channel because the most civilized gentlefolk on the list are to be found here, as well as the most lucid and learned commentary. Sure, I state my thoughts...but mainly to LEARN, not to hear myself talk. I've learned more from these little debates than from any other single source in my lifetime, with the possible exception of the "Audio Cyclopedia" of yore.

Within this thread there are a couple of folks who will be happy to flame you to fine carbon if you wish. Been there, done that, learned nothing of value.

therwise, don't hold your breath. This is NOT the dark side.

Dave

[Jimmy James]

Jimmy:

I've learned more from these

little debates than from any other single source in my lifetime, with

the possible exception of the "Audio Cyclopedia" of yore.

Dave

That's so sad. I'm sorry to hear that.

[Allan Songer]

I'm the guy that's looking for the 2-channel forum, not the Chevy's better than Ford debating society.

[Mallette]

Maxg:

Thanks for a great thread. I've thoroughly enjoyed it and learned a lot. As you mentioned, there's been only a hint of smoke, more like passion, and a lot of tolerance for wide points of view.

Would I spend as much as you did for a 'table? Dern tootin'....

Dave

[charlieboy]

With turntables like this theres no way cd can compete.