On Thu, 22 May 2008 16:50:38 +0100, Jim Lesurf
wrote:

Just to let people know I've just added some new material to the
'audiomisc' site. :-)

A) Page on Radford and Bailey, and their power amps. This is based on a HFN
article from last year, but I have extended the article. I've also tied it
in to circuit diagrams of some of the relevant designs. (The diagrams were
already on the site, but until now there were no links to them, so you had
to know where they were!)

B) First of the series of HFN articles on LP performance. This deals with
the maximum signal levels that can be recorded/replayed.

Will shortly add another page where I show results of measurements of the
peak levels found on various LPs.

Slainte,

Jim

JIm, there is another point you might want to consider, which is that
Shannon's limit applies only to data transmitted over the defined
path. But music in particular is not like that. When we listen to
familiar music it is already stored in our brain and all that is
necessary to trigger it is a very small correlation from the signal;
it is a little like CDMA from this point of view - a clean signal can
be recovered from an apparently impossible signal to noise ratio
because the spreading code is known at both ends of the link, and
doesn't not actually get transmitted and received.

So a familiar tune sunk well into the noise will be heard, while
random notes may be missed.

I know this is not what your article is about, but I think it is
relevant and you never know, may be worth a research grant to quantify
the effect.

d

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