"Andrew Walkingshaw" wrote in message
...
In article , RobH wrote:

I'm not sure that last sentence makes sense. Are you saying that the
theoretical limit of vinyl recording is at an atomic level?

It probably is if you use an AFM[1] as your stylus. (Pressing the
discs
would be a right pain, though. :-) )
Well, if IBM can construct their logo using individual atoms I don't see
why they can't adopt this technology for making records. ;-)



Now I've suggested it, someone is probably mad enough to try this...

- Andrew

[1] Atomic Force Microscope; works by dragging a needle over the
surface in question, where it bounces off the electron clouds of
the
atoms composing said surface. Materials scientists love them.

But then you get into the realms of Quantum Mechanical effects, the
Uncertainty Principle et al
You could then start to debate the probability of the "record" being
accurate but let's not go there.



--
RobH
The future's dim, the future's mono.

In article , RobH wrote:

"Andrew Walkingshaw" wrote in message
...
In article , RobH wrote:

I'm not sure that last sentence makes sense. Are you saying that the
theoretical limit of vinyl recording is at an atomic level?

It probably is if you use an AFM[1] as your stylus. (Pressing the
discs would be a right pain, though. :-) )

Well, if IBM can construct their logo using individual atoms I don't see
why they can't adopt this technology for making records. ;-)

True, it's entirely *possible*. Cost a bob or three, though - I wonder
if the vinylphiles here would want to pay a seven-figure sum per
record...

But then you get into the realms of Quantum Mechanical effects, the
Uncertainty Principle et al

[This is a really bad explanation. I'm sorry. I'm trying to think of
a good way of describing this without resorting to digging out a copy
of Kittel and writing a bunch of equations... there's so much potential
for making a fool of myself here, given I'm allegedly some sort of
condensed-matter physicist ]

Nah, what you see is a statistical average; the motion of the needle is
orders of magnitude slower with respect to that of the electrons, so you
can assume that the system reacts instantaneously to any change in
stylus position.

Any bizarre effects are on a much shorter timescale than an AFM
measurement, and so all you'll "see" is a statistical distribution - the
ground state electron density.

- Andrew (day job: grad student, "First-principles electronic structure
calculations for disordered systems")

--
Andrew Walkingshaw |

In article , Andrew
Walkingshaw wrote:
In article , RobH wrote:

"Andrew Walkingshaw" wrote in message
...
In article , RobH wrote:

I'm not sure that last sentence makes sense. Are you saying that
the theoretical limit of vinyl recording is at an atomic level?

It probably is if you use an AFM[1] as your stylus. (Pressing the
discs would be a right pain, though. :-) )

Well, if IBM can construct their logo using individual atoms I don't
see why they can't adopt this technology for making records. ;-)

True, it's entirely *possible*. Cost a bob or three, though - I wonder
if the vinylphiles here would want to pay a seven-figure sum per
record...

Given that it would probably also tend to increase the effective noise
level and produce noticable undithered quantisation distortion as well, I
doubt most people would prefer it. :-) Bear in mind a conventional LP
system makes good use of the 'averaging and dithering' effects of using a
large number of molecule positions affecting the stylus at any moment to
reduce these effect as the sacrifice of bandwidth and a larger groove/LP
for a given duration.

But then you get into the realms of Quantum Mechanical effects, the
Uncertainty Principle et al

The poor are always with us... ;- Fortunately, the above are very useful
for averaging purposes.

Agree with your point btw that the forces are electromagnetic, hence it is
the electron clouds, etc, that do the work. However these are shaped by the
molecules in 'PVC' (sic).

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html

When I talk about analogue/digital here is really in the less specific
context of continuous and discrete data. This is going OT, and maybe I've
got it wrapped around my head the wrong way, so I reserve the right to be
wrong...

For me anything that is discrete may be said to be digital, since it may be
expressed as a number (in any radix, as binary if it helps). Whereas for
anything which is continuous, any value, possibly between extremes, I think
of as analogue. A continuous value is almost certainly an irrational
number, and so can not be expressed numerically without approximation. It
is not to the nearest anything, but it will always contain errors. You can,
however, say the accuracy to which you can measure the analogue thing with
reasonable precision.

When I talk about things being atomic/axiomic I didn't always mean atoms
(although in one case I did) I was mostly referring to the smallest
possible unit of sound for music storage, for cds this is the 32 bits that
are played at any one time. For vinyl it is less clear what the smallest
possible unit is, because for most day to day purposes we consider solid
objects to be continuums, so I suggested vinyl atoms as a side point.

Accuracy and precision are similar ideas, degree of approximation. Very
simply accuracy is 'to the nearest x' whilst precision is the presence of
errors.

Btw, I tend to prefer digital music, this was not a 'vinyl is better',
analogue is perfect thread.

--
Jim H
remember, I reserve the right to be wrong.

In article , Jim H wrote:
Accuracy and precision are similar ideas, degree of approximation. Very
simply accuracy is 'to the nearest x' whilst precision is the presence of
errors.

To put it another way, if I understand you correctly: there's a
tradeoff.

Vinyl has more noise, in the statistical sense: however, it also has
a theoretically higher resolution than CDs. Therefore, the question
of which is "better" depends on three things:

a) What is the maximum resolution of the ear?
b) What's the lowest practical noise-floor of vinyl?
c) How much (or, indeed, *is* it?) higher is the *practical* resolution
of vinyl than CD under typical circumstances?

I can't think of a good way of testing any of these hypotheses.

- Andrew (who thinks the biggest component of the vinyl/CD
perceived-difference is probably psychological)

--
Andrew Walkingshaw |

"Andrew Walkingshaw" wrote in message

In article , Jim H wrote:
Accuracy and precision are similar ideas, degree of approximation.
Very simply accuracy is 'to the nearest x' whilst precision is the
presence of errors.

To put it another way, if I understand you correctly: there's a
tradeoff.

Vinyl has more noise, in the statistical sense: however, it also has
a theoretically higher resolution than CDs.

Wrong. If you look at the definition of resolution, having more noise
automatically precludes having more resolution.

Therefore, the question
of which is "better" depends on three things:

a) What is the maximum resolution of the ear?

Irrelevant since the ear almost always operates in relatively noisy
environments.

b) What's the lowest practical noise-floor of vinyl?

A lot less than that of good musical recordings.

c) How much (or, indeed, *is* it?) higher is the *practical*
resolution of vinyl than CD under typical circumstances?

That would be a negative number for reasons stated above.

I can't think of a good way of testing any of these hypotheses.

They've all been tested.

- Andrew (who thinks the biggest component of the vinyl/CD
perceived-difference is probably psychological)

Vinyl preference most likely has psychological, not technical causes.

A certain Andrew Walkingshaw, of uk.rec.audio "fame", writes :

Vinyl has more noise, in the statistical sense: however, it also has
a theoretically higher resolution than CDs.

No it doesn't.

a) What is the maximum resolution of the ear?

The million dollar question.

b) What's the lowest practical noise-floor of vinyl?

Around about -55db on the best ? (guess)

--

"Jokes mentioning ducks were considered particularly funny." - cnn.com

In article , Chesney Christ wrote:
A certain Andrew Walkingshaw, of uk.rec.audio "fame", writes :

Vinyl has more noise, in the statistical sense: however, it also has
a theoretically higher resolution than CDs.

No it doesn't.

I was guessing. Looks like I'm wrong on this. Never mind

- Andrew

--
Andrew Walkingshaw |

"Chesney Christ" wrote in message


A certain Andrew Walkingshaw, of uk.rec.audio "fame", writes :

Vinyl has more noise, in the statistical sense: however, it also has
a theoretically higher resolution than CDs.

No it doesn't.

a) What is the maximum resolution of the ear?

The million dollar question.

No, its well known.

At any one point in time its about 60 dB, but the ear's dynamic range window
can slide up and down another 40 dB or so. IME it takes about 80 dB to have
a practically transparent recording medium, and ideally it takes about 100
dB or a bit more.

The CD format has about 93 dB dynamic range in practice. So its generally
good, even overkill.

b) What's the lowest practical noise-floor of vinyl?

Around about -55db on the best ? (guess)

On a really good day about 10 dB better than that, on other days, about 10
dB worse. IOW the measured dynamic range of LP recordings ranges from about
45 to 65 dB.

In article , Andrew
Walkingshaw wrote:
In article , Jim H wrote:
Accuracy and precision are similar ideas, degree of approximation.
Very simply accuracy is 'to the nearest x' whilst precision is the
presence of errors.

To put it another way, if I understand you correctly: there's a tradeoff.

Vinyl has more noise, in the statistical sense:

Probably.

however, it also has a theoretically higher resolution than CDs.

Not so far as I am aware.

Therefore, the question of which is "better" depends on three things:

a) What is the maximum resolution of the ear?

This depends upon the circumstances.

b) What's the lowest practical noise-floor of vinyl?

One aspect of this is covered in the "Scots Guide" (part 12 of the
"Information and Measurement" section).

c) How much (or, indeed, *is* it?) higher is the *practical* resolution
of vinyl than CD under typical circumstances?

I think you will find that in practice it tends to be lower.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc. http://www.st-and.demon.co.uk/JBSoc/JBSoc.html