CD transports and resonance
 

"Dave Plowman (News)" wrote in message

In article ,
Andy Evans wrote:
But evidently you can't explain an obviously audible phenomenon.

Trouble is, Andy, most of your posts concern 'audible phenomenon' that
only you can hear...

No doubt, its all an illusion. Poor Andy has never heard of "Constructor's
ear" even though he is obviously experiencing it.

CD transports and resonance
 

"Andy Evans" wrote in message


The difference is quite audible, as I said, so I'm interested in
knowing how resonance dampening affects CD transports.

It can only have an effect if the transport is subjected to external
vibration sufficient to make it miss-track in some way.(DP)

Agreed.

Why not internal vibration? This is considerably larger than anything
external. As I've said, the effect of damping the motor vibrations by
fixing it to an alu slab is most audible in highly modulated
passages. This should give a clue to something. Andy

All we know right now Andy is that your listening evaluation procedures are
highly-flawed.

CD transports and resonance
 

there's no assurance that there is in fact an audible phenomenon.

Apart from the fact that I can hear it. There's no assurance that you have any
technical knowledge that can explain it. I don't mind the fact that you can't
explain it - our knowledge always has limitations.

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

CD transports and resonance
 

In article ,
Andy Evans wrote:
there's no assurance that there is in fact an audible phenomenon.

Apart from the fact that I can hear it.

I'm afraid that's only a 'fact' to you. To be certain it's not just your
imagination requires proper testing.

Fooling oneself that a 'tweak' produces an audible improvement is as old
as tweaks themselves.

--
*Proofread carefully to see if you any words out or mispeld something *

Dave Plowman London SW
To e-mail, change noise into sound.

CD transports and resonance
 

On Sat, 06 Nov 2004 13:52:46 +0000, Dave Plowman (News) wrote:

In article ,
Andy Evans wrote:
there's no assurance that there is in fact an audible phenomenon.

Apart from the fact that I can hear it.

I'm afraid that's only a 'fact' to you. To be certain it's not just your
imagination requires proper testing.

Fooling oneself that a 'tweak' produces an audible improvement is as old
as tweaks themselves.

Don't feel bad about this, Andy. I think I can safely say that we have
*all* gone through this. It appears that human hearing is easily fooled by
psychological factors that have *nothing* to do with the sound waves
entering the ear. Hi-fi manufacturers and magazines depend on this for
their living...

--
Mick
(no M$ software on here... :-) )
Web: http://www.nascom.info

CD transports and resonance
 

Don't feel bad about this, Andy. I think I can safely say that we have
*all* gone through this. It appears that human hearing is easily fooled by
psychological factors

Hello Mick - I'm a psychologist specialising in music and musicians, as it
turns out, so I'm not unfamiliar with psychological factors! Anyway, to start
from the beginning - I sought to replicate the CD transport of Japanese
designer Junji Kimura, who worked for Pioneer, Trio and Kyocera. He uses a
thick aluminium slab to support the transport. See
http://www.soundstage.com/revequip/4...rogression.htm
I talked to this guy at the London HiFi Show. He is quite eccentric, but
definitely recommended mounting the transport on an alu slab. I was using a
CD-ROM at home which was rather 'shouty'. I changed the switchmode PSU for a
normal toroid, which helped a bit, then mounted the unit on an alu slab, which
helped more, particularly smoothing out highly modulated pasages. If you pick
up a CD-ROM while it's playing you can feel the vibrations quite clearly, so we
know that there is vibration present. Now, to my ears there was a significant
change in the sound, not just a slight change which I would - just as you say -
be sceptical about and attribute to 'causes unknown'.
I posted this in case it was of some use to other ng members - its useful to
hear about various tweaks even if they might not be relevant or replicable in
one's own system. Fine. But I also asked if anyone else had an explanation or
empirical evidence of the effects of damping on CD mechanisms. I've had various
responses, none of which are based on empirical evidence of exactly that. So if
this is outside the experience of those posting, It would be honest and simple
to say "Sorry, Andy, I don't have any experience of this". Since I would be
interested in some empirical knowledge, I'll post this on other forums and ask
some of my friends in the audio industry. As I said at the start, this is based
on an actual product, the designer of which clearly does have empirical
knowledge.

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

CD transports and resonance
 

To resolve, employ suitable measurements. Otherwise we (including you) have no
real idea if the effects you describe have anything to do with the 'causes' you
assume.

Hello Jim - I'm open minded - my assumption is that it's to do with resonance,
I suppose, but I've been very clear in saying I don't understand how this
happens. I'm not in a position to measure, so my next step is to find others
who have observed similar things and others who can offer some kind of
explanation based on their own empirical knowledge. Andy

=== Andy Evans ===
Visit our Website:- http://www.artsandmedia.com
Audio, music and health pages and interesting links.

CD transports and resonance
 

In article , Andy Evans
wrote:
I have no wish to 'endow' (DP) anything. I'm reporting less distortion
in highly modulated passages when a transport is damped.

Not quite. You are reporting that you think you can hear a difference.
However you are not actually providing any evidence that would tell us
either:

A) If the difference is real.

or

B) what its nature or cause (if real) might be.

So far I've had no explanation. I don't mind if this is outside the
subjective technical knowledge of posters - our knowledge always has its
limits.

The difficulty is not with the lack of technical (or subjective) knowledge
of others. The difficulty is that your descriptions don't give us much in
the way of reliable or relevant data that would allow others to make a
plausible diagnosis.

This does not mean that we can all be certain the difference is entirely
imaginary. Simply that we have no real way of telling much beyond noting
that you think you hear something. Then putting this into the context where
some of us generally may not hear the differences you claim in apparently
similar circumstances in our own experience.

This represents one of the fundamental problems with 'subjective' options
which do not come with either any relevant measurements or a plausible
physical hypothesis. The subjective 'discription' you give has no clear
information content for anyone who was not using your ears at the time, or
who does not already by some other means know exactly what you are talking
about.

I'm afraid that if you want to actually understand what may be the cause of
what you hear, and how systematic advice or diagnosis may be given, then
you may have to move beyond simply giving a subjective comment. Otherwise
I'm afraid that you do not give others any real basis for providing much
help.

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

CD transports and resonance
 

In article , Andy Evans
wrote:
there's no assurance that there is in fact an audible phenomenon.

Apart from the fact that I can hear it.

Or, rather, you *think* you can hear a difference and *assume* it is
associated with what you describe. However your descriptions don't really
provide any information that could be used as the basis for assessing if
any specific 'explanation' was plausible.

There's no assurance that you have any technical knowledge that can
explain it. I don't mind the fact that you can't explain it - our
knowledge always has limitations.

Equally, we have no assurance that your descriptions are a reliable guide
to what actually may be occurring.

If you can't provide reliable and relevant data, why should you expect
anyone to be able to offer any explanation?

Consider walking into a jeweller's shop and saying, "My watch doesn't keep
time. Tell me exactly what's wrong with it." But then declining to either
provide the watch for examination or answer the jeweller's questions, or
carry out any test he may suggest. Would you expect him to tell you what
was wrong with the watch?

Slainte,

Jim


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

CD transports and resonance
 

In article , Andy Evans
wrote:

[snip]

If you pick up a CD-ROM while it's playing you can feel the vibrations
quite clearly, so we know that there is vibration present. Now, to my
ears there was a significant change in the sound, not just a slight
change which I would - just as you say - be sceptical about and
attribute to 'causes unknown'. I posted this in case it was of some use
to other ng members - its useful to hear about various tweaks even if
they might not be relevant or replicable in one's own system. Fine.

You may recall that in response I posted details of some damping, etc, I'd
applied to a player of my own. Along with which I suggested possible
reasons for a change.

But I also asked if anyone else had an explanation or empirical evidence
of the effects of damping on CD mechanisms.

See above.

I've had various responses, none of which are based on empirical
evidence of exactly that.

See above.


So if this is outside the experience of those posting,

See above.

Also consider the possibility that the problem is that you have given
others no real information which would permit a plausible diagnosis to be
suggested.

It would be honest and simple to say "Sorry, Andy, I don't have any
experience of this".

Alternatively, you could note that some of us do have some 'experience' of
some effects that *might* be relevant, but that we can't really say as you
have not provided us with any evidence or information that would allow us
to decide. i.e. perhaps the problem is primarily due to the lack of
relevant info you have given...

I'm afraid, Andy, that you will keep encountering effects which will seem
to you like "mysteries of science" until such time as you wish to put the
required time and effort into being able to make relevant tests and collect
relevant evidence that would allow a systematic explanation to be
established in a reliable manner. Without this info, there is not much
other can do by guess or try things at random.

I'm afraid this is really why some people fail to take your reports very
seriously. I'd very much like to help, but I reget to say that you do make
this somewhere between 'difficult' and 'impossible' at times by the way you
proceed, and describe what you think is happening. :-/

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