wrote:
D.T.N. WILLIAMSON AMPLIFIER

In the late 1940's, component Hi Fi was a hobby, much like amateur
radio. Amateur radio buffs built their own transmitters from parts
they bought in electronic distributor stores. A lot of these amateurs
had component sound systems as part of their overall short wave radio
systems. As industry changed over from wartime products to civilian
products, the electronic industry began making various parts for these
electronic distributors. Among these parts were audio amplifiers, raw
speakers and the like. Because there was a scarcity of parts in the
beginning, many small manufacturers found a ready market for their
electronic components. For many years, these small manufacturers
produced most of the audio electronic parts.

So far so good, although the hard core buildasauruses used headphones
and disdained open speakers for serious "DXing".


Magazines to serve the nascent component audio hobbyists appeared.
These magazines had similar format to the amateur radio magazines and
sometimes contained both amateur radio and audio gear. They published
numerous articles on various designs relating to electronic components.
Almost anyone could get published, as the magazines needed articles to
fill up their issues. This is why there are so many different audio
tube designs floating around. No one in the media world separated the
wheat from the chaff. As few people around today are familiar with the
technology of audio tube design, the chaff has puffed along with
reputable designs as "antique audio". There are a lot of bad ideas out
there along with the good ones. Let the buyer beware.

There were schlock publications galore, most notably anything
connected to Hugo Gernsback. A long-lived bunkum artist whose name
still resonates with the Hugo Award for science fiction writing, his
publications-numerous magazines and the paperback Gernsback Library
which became G/L-TAB Books- were often pure horse poop.Nonetheless,
C.G.McProud and i Audio Engineering /i magazine set a high standard
with contributors like Sarser and Sprinkle, Hafler, Keroes, Klipsch,
Curtis Schafer and others.


The Original Williamson Amplifier

Into this free wheeling media milieu, Williamson published an article
on audio amplifier design, which impressed everyone with the insight
into audio amplifier theory. Williamson gave certain criteria for
audio amplifier circuitry that broke new ground. Williamson's concepts
were valid, his articulation of his ideas into an amplifier were
seriously flawed. A basic component of his amplifier was the Partridge
transformer, a creation of Dr. Partridge. The Partridge output
transformer had a frequency response from 2 to 200,000 Hz. Its output
was 10 watts over most of the range. This quality level for an output
transformer was a milestone in the development of Hi Fi. Ten watts of
audio in 1949 was about the best that most were doing at the time. It
is not known that a Williamson produced amplifier was ever offered as a
unit to the American market. Williamson himself, an engineer employed
by a tube company never produced the amplifier at all. The Partridge
transformer was sold in America as a component and was available
through electronic distributors.


This is pure bunkum and horse poop, Stan.

DTN Williamson did indeed publish, over several issues of the British
magazine i Wireless World /i the Williamson Amplifier: he built a
prototype complete with a complete "Wickelschema" or wind sheet for the
nine-layer OPT for the hobbyist to tediously wind himself. And he wrote
it up so well that audiophiles all over the world, even behind the Iron
Curtain, in Africa, and everywhere else, built Williamsons. The article
has been reprinted in pamphlet form in numerous reprint editions even
to the present day.

http://www.audioxpress.com/bksprods/books/cdaa2.htm

American builders usually bought transformers as opposed to winding
them, but usually from American wind houses such as Triad, UTC,
Peerless, Freed, or the like. Partridge trasformers were never marketed
in the US to any substantial degree.