Archived posting to the Leica Users Group, 1996/10/20

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Subject: Re: 35mm Asph./ASPHERICAL
From: dmorton@cix.compulink.co.uk (David Morton)
Date: Mon, 21 Oct 96 04:46 BST-1

In-Reply-To: <199610160042.UAA18460@worldy.worldy.com>
> Unfortunately, this is not true regarding high end excellent sounding 
> audio
> equipment. You can design equipment which will test excellent on the 
> bench
> and sound terrible. Early transistor designs were a proof of this.

Well yes, but that was understandable. The designers treated the new 
transistors very much like valves, while the latter were much more 
predictable, and exhibited *far* better linearity, having been developed 
for decades.
 
> The 
> were
> designed to have both thd, im distortion and frequency response which 
> would
> beat tube equipment, but sounded absolutely terrible.

Actually I think those errors came later with the replacement of 
germanium devices with silicon. All of a sudden the designers had 
*oodles* of gain, and were tempted to throw negative feedback at any 
problem in sight. You don't get a good amplifier by wrapping -ve feedback 
round a crap one.

A failure on the part of the engineers to realise that, and a consequent 
failure to identify transient intermodulation distortion, opened the door 
to the subjectivists (who were correct in this instance, though in few 
matters subsequently), and so lead to much of the reprehensible science 
at the 'snake oil' end of the audio industry.

dmorton@cix.compulink.co.uk      |  "The loss of an old man
david@cassandra.compulink.co.uk  |  is like the destruction
Kilburn, London, England.        |  of a library"