On Tue, 1 Aug 2006 17:43:47 +0100, "Paul" wrote:


snip

It is neither a bodge nor a fix. It is a way of using a resource that
would otherwise be wasted - high frequency headroom. An exactly
matched amplitude/phase curve is exactly equivalent to flat frequency
and phase, and there is no problem whatever in making that match.

Oops, missed a bit!
Why would you wish to perform two unnecessary conversions?
How can you be sure of an *exact* match?
Surely it is unwise to add any unnecessary circuitry.

Paul


Please, just go find a book on the subject and find out why you can do
it, and how it all works. There is too much to explain right here.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Paul" wrote in message
...


Please enlighten all by detailing what the technical specifications of a
reproduction medium must be for it to be categorised "High Fidelity", and
therefore where you draw the line.

I am not trying to enlighten - I have no interest in that area. (Do *all*
need enlightenment?)

What I find interesting is the stubborn unwillingness of many to
acknowledge
widely held and believed scientific principles.
Do you, or others, consider that physics does not apply to the vinyl
issue?
If so, and you can provide reliable, repeatable evidence, you are in a
position to turn science on its head. I envy you - you will become a
household name over night. So, can we please put that one to bed?

Ok, lets forget technical specs for a moment. The *highest* fidelity will
be
attained when the reproduced sound is identical to the source.
This would be verified, or not, by comparison using calibrated
instruments.
Simple isn't it? Obviously I am not referring to comparison by ear which
is
not calibrated and, in many cases, is faulty. Sure, that will tell you
which
system is preferable to you and your ears but is meaningless in terms of
Hi-Fi. This should be obvious due to the fact that we don't find 100% of
the
listeners choosing the same system. So who is picking the best system?
With
this method of selection I would suggest they all are!

Current technology may or may not yet allow the *highest* fidelity - I
don't
know. However, by comparison with a replicable sound source, it will let
us
identify the which comes closest. High Fidelity sits at the top of the
(current) tree.
It should be clear that you can only draw a line when there is something
both above and below it. Therefore there is no line to be drawn.
If you are one of the many who have a need to be able to proclaim 'my
system
is above the line' then fine. I have absolutely no problem with that and
why
should I?

Paul

PS Is that you Keith?



Is *what* me?

Are you making the mistake of thinking I *don't* have about 500 CDs, 15,000
MP3s and 500 DVD-Videos here?

(Not to mention DAB and FV radio, two 'media computers' with DL DVDRW
drives, a selection of digital PVRs, STBs, CDPs, DVDPs and a couple of
Digital Projectors....???)

You'll be joining the ranks of those here (OK, one clown actually....)
calling me a 'Flat Earther' next.....!!

I can't see how its a bodge, its a filter, that is designed to be
matched with a inverse on replay. Remember there is a similar (though for
different reasons) filter employed in the recording and replay of CD's,
again, without that filter the CD experence would be equally appalling
(maybe worst without the initial filter before the AD, and even with a DDD
disk, somewhere there will be a AD step unless you are listening to just a
digital synth).

If it gets you less upset don't think of it as a filter, think of it as a
converter from a position detection to a velocity detection system and the
reverse at playback.

--
Nick

Hold on a mo. We are drifting aware from my original purpose.
My interest is with High Fidelity and how best it can be achieved with
available technology.
It is probably clear that my preference of those available is CD. However, I
am not saying CDs don't have issues. I have no desire to tread this well
worn path.
It is also clear to me that CD is today's more capable medium. It can be
proven to be the better of the bunch! Consequently, it demonstrates that the
others aren't.
High Fidelity is my holy grail. I don't care what is inside any little black
box as long as it produces a sound output closest to the original sound
producing source. That's the one I would go for until something better (or
indeed the grail) comes alone. If it can be demonstrated to me that a wax
cylinder is the better of those available then I would be legging it down to
the shops! I really don't give a monkeys if it is something out of the
Flintstones or a 'doesn't it glow lovely with the lights out' rig as long as
it gets as close as possible. That can only be determined by comparison with
the original sound producing source. I have no interest in the 'Emperors new
coat' style of evaluation.

Going back to my synth experiment. Does anybody see a problem? Am I missing
something? A simple 'no' would suffice if you believe it to be sound.
On the other hand, if you consider it to be flawed then a please tell me
where I am going wrong.

Paul

On Tue, 1 Aug 2006 17:26:04 +0100, "Paul" wrote:


"Don Pearce" wrote in message
...
On Tue, 1 Aug 2006 16:32:38 +0100, "Paul" wrote:

snip

It is neither a bodge nor a fix. It is a way of using a resource that
would otherwise be wasted - high frequency headroom. An exactly
matched amplitude/phase curve is exactly equivalent to flat frequency
and phase, and there is no problem whatever in making that match.

Are you telling me that an RIAA filter is optional for vinyl?
My understanding is that it is a prerequisite and that it has to be employed
because it is impossible to cut a groove at high frequencies (perhaps even
low frequencies). The same being true for retrieval - a stylus simply could
not track it accurately even if it could be cut. Without it's use, the vinyl
experience would be appalling.
I believe that, because of the limitations, information is
compressed/omitted/converted or whatever and reconstituted in the amp. Am I
wrong here? I am more than happy to be told when I am wrong. If I am
correct, it is a bodge etc put in place to overcome limitations.


All pre-emphasis is optional - but things audio tend to work more
effectively with it, particularly vinyl, which needs all the help it
can get in terms of signal to noise ratio. FM radio uses pre-emphasis
simply because it is a good idea - it makes it a bit quieter. Many
years ago it was observed that the amplitude vs frequency distribution
of music and speech was heavily weighted to the bottom end. This meant
that there was a huge amount of modulation capacity going to waste at
the top end. It was an obvious thing to do to boost the top end
frequencies to fill that space, then cut them back again at the
receiver. It is trivially easy to match the two curves to a small
fraction of a dB.


And do remember that the CD specification includes the option to use
pre-emphasis.

But is it used? More to the point, as it is optional, it is clear that it
isn't necessary.

You will never know. Your CD player won't tell you. If you play mainly
modern pop you can be sure it isn't used, because that kind of music
tends to fill the frequency space without de-emphasis.

d

--
Pearce Consulting
http://www.pearce.uk.com

I do wonder if you've heard either at its best. I have a Revox reel to
reel with a Dolby SR unit around it which gives results as near as dammit
to 16 bit PCM. FM radio can also be pretty good - although these days the
dreaded optimod type devices often ruin it.

Ok, I will take your word for it being very good. No I'm not taking the
mick - Revox have made some bloody good kit. In fact I would love one for
little jobs in my home studio - but not for Hi-Fi. I don't even use tape for
acoustic instruments - I go straight to harddisk. By your own admission it
only comes close to 16 bit PCM. It therefore falls short of what can be
obtained and misses the mark for me. If you have read my earlier posts you
may understand why this has no place in my agenda.

Paul

On Tue, 1 Aug 2006 18:46:21 +0100, "Paul" wrote:


I do wonder if you've heard either at its best. I have a Revox reel to
reel with a Dolby SR unit around it which gives results as near as dammit
to 16 bit PCM. FM radio can also be pretty good - although these days the
dreaded optimod type devices often ruin it.

Ok, I will take your word for it being very good. No I'm not taking the
mick - Revox have made some bloody good kit. In fact I would love one for
little jobs in my home studio - but not for Hi-Fi. I don't even use tape for
acoustic instruments - I go straight to harddisk. By your own admission it
only comes close to 16 bit PCM. It therefore falls short of what can be
obtained and misses the mark for me. If you have read my earlier posts you
may understand why this has no place in my agenda.

Paul


Why are you only using 16 bit PCM? Surely your sound card can manage
24/96 - that is pretty much the standard these days.

d

--
Pearce Consulting
http://www.pearce.uk.com

"Paul" wrote in message
...

I do wonder if you've heard either at its best. I have a Revox reel to
reel with a Dolby SR unit around it which gives results as near as dammit
to 16 bit PCM. FM radio can also be pretty good - although these days the
dreaded optimod type devices often ruin it.

Ok, I will take your word for it being very good. No I'm not taking the
mick - Revox have made some bloody good kit. In fact I would love one for
little jobs in my home studio - but not for Hi-Fi. I don't even use tape
for acoustic instruments - I go straight to harddisk. By your own
admission it only comes close to 16 bit PCM. It therefore falls short of
what can be obtained and misses the mark for me. If you have read my
earlier posts you may understand why this has no place in my agenda.



You need to loosen up, matey - get one of these:

http://www.thanko.jp/ibluetube/

and try and get a little *fun* out of the hobby....

Is *what* me?

Are you making the mistake of thinking I *don't* have about 500 CDs,
15,000 MP3s and 500 DVD-Videos here?

(Not to mention DAB and FV radio, two 'media computers' with DL DVDRW
drives, a selection of digital PVRs, STBs, CDPs, DVDPs and a couple of
Digital Projectors....???)

You'll be joining the ranks of those here (OK, one clown actually....)
calling me a 'Flat Earther' next.....!!


Keith, I have no idea what you have.
Trust me, I have no intention of calling you anything - I don't indulge in
such nonsense. In fact, should this discussion(?) degenerate to that level
(as many seem to do) I'm out of here! I won't be applying for membership to
anything and I would appreciate it if people will avoid nominating me!
I would imagine that you get great enjoyment from your listening
experience - that's what it's about isn't it.
I accept that many like to tinker and audio is a hobby to them. I have no
problem with that - it's none of my business anyway.
My 'problem' (obsession?) is that I want a system that will get me as close
as possible to the original sound.
In my quest it is clear to me that some get closer than others. It is
unfortunate that, in highlighting the less capable ones (and demonstrably
so), some people get upset. Is that my fault? I don't believe so but if it
is, I apologise.
At the end of the day, if a listener is happy with their system then that's
all that matters.
In the mean time, I'll plough on.

Paul

snip

Why are you only using 16 bit PCM? Surely your sound card can manage
24/96 - that is pretty much the standard these days.


I thought we were talking about a comparison with CD.
For my studio I use an M-Audio 2496 Pro audio card (no sound generating
capability). I'm very pleased with it.
No doubt I could do better but funds wont allow and I don't feel a need to
change. It does a fine job though and I would recommend it to anyone
involved with home recording etc.
PC sound cards are inadequate but then, to be fair, they are not designed
for it.

Paul

You need to loosen up, matey - get one of these:

http://www.thanko.jp/ibluetube/

and try and get a little *fun* out of the hobby....


Well, if nothing else Keith, you've given me a good laugh Thanks for
that.
What the hell is that? Second thoughts, don't tell me. There is an ipod
thingy in there somewhere - yuk.
Are they having a laugh?

I have absolutely no interest in Hi-Fi as a hobby.

Paul

PS Please don't tell me you have one else this thread will seriously spiral
out of control