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previous: rmike Not to be argumentative, but wasn't... -- 6/28/2000 8:54 PM

Re: Celestion Getting Out of Guitar Speaker Business???

7/1/2000 11:54 PM
Uncle Ned	Re: Celestion Getting Out of Guitar Speaker Business??? "Not to be argumentative, but wasn't the Bassman and a number of other classic Fender circuits almost verbatim copies of classic (RCA? or some other?) tube audio circuits? Maybe someone else can elaborate on the details of this." Mike, the basics of nearly every circuit used in tube audio amplifiers are in the RCA Radiotron Designer's Handbook 4th Edition, so in a sense you could say every guitar amp was copied out of an RCA book. But it's not really true, because the RDH i s really a condensed compilation of what was known about using recieving tubes at the time it was published. Langford-Smith (the author) cites hundreds of sources for the information contained in it. Lots & lots of time and money were spent researching and devising about every possible circuit could be of any use using tubes and patenting them, by 1950 or so, it would've been pretty hard to build an amp that didn't contain patented circuits or ones that were out of patent but had been done previously. The deal with RCA & AT&T was pretty complicated (originally, RCA was owned jointly by AT&T, General Electric, Westinghouse and American Marconi), but both owned loads of patents and basically what happened was that tube circuits licensed for consumer use were licensed by RCA, circuits licensed for commercial use or public performances (like a guitar amp) were licensed by AT&T. A lot of home equipment used certain circuit segments (like phase splitters) that were the same as what were in 50's Fenders, but they don't have AT&T license notices. IOW, the fact that a piece of gear has an AT&T license notice, doesn't necessarily mean the circuits inside were designed by AT&T. If one has a patent number, one certainly could track down who owned the patent.

7/1/2000 11:54 PM

Uncle Ned

Re: Celestion Getting Out of Guitar Speaker Business???

"Not to be argumentative, but wasn't the Bassman
and a number of other classic Fender circuits
almost verbatim copies of classic (RCA? or
some other?) tube audio circuits?
Maybe someone else can
elaborate on the details of this."

Mike, the basics of nearly every circuit
used in tube audio amplifiers are in the
RCA Radiotron Designer's Handbook 4th Edition,
so in a sense you could say every guitar amp
was copied out of an RCA book.
But it's not really true, because the RDH i
s really a condensed compilation of what
was known about using recieving tubes at
the time it was published.
Langford-Smith (the author) cites hundreds of
sources for the information contained in it.

Lots & lots of time and money were spent
researching and devising about every possible
circuit could be of any use using tubes
and patenting them, by 1950 or so, it would've
been pretty hard to build an amp that didn't
contain patented circuits or ones that were
out of patent but had been done previously.

The deal with RCA & AT&T was pretty complicated
(originally, RCA was owned jointly by AT&T,
General Electric, Westinghouse and American
Marconi), but both owned loads of patents
and basically what happened was that
tube circuits licensed for *consumer* use
were licensed by RCA, circuits licensed
for commercial use or public performances
(like a guitar amp) were licensed by AT&T.
A lot of home equipment used certain circuit
segments (like phase splitters) that were the
same as what were in 50's Fenders, but they don't
have AT&T license notices.

IOW, the fact that a piece of gear has
an AT&T license notice, doesn't necessarily
mean the *circuits* inside were designed by AT&T.

If one has a patent number, one certainly
could track down who owned the patent.

Replies:

SpeedRacer Thanks (again) Uncle Ned.. that's t... -- 7/2/2000 4:19 AM