From timtub–(at)–ol.com Mon Jan 27 09:52:42 CST 1997
Article: 36054 of alt.guitar.amps
Path: geraldo.cc.utexas.edu!cs.utexas.edu!howland.erols.net!newsxfer3.itd.umich.edu!portc01.blue.aol.com!newstf02.news.aol.com!audrey01.news.aol.com!not-for-mail
From: timtub–(at)–ol.com
Newsgroups: alt.guitar.amps
Subject: Re: RCA STR387’s??
Date: 27 Jan 1997 13:02:32 GMT
Organization: AOL http://www.aol.com
Lines: 21
Message-ID: <19970127130200.IAA2700--(at)--adder01.news.aol.com>
References: <854359110.2748--(at)--ejanews.com>
NNTP-Posting-Host: ladder01.news.aol.com
X-Admin: new–(at)–ol.com
X-Newsreader: AOL Offline Reader

In article <854359110.2748--(at)--ejanews.com>, emeson–(at)–lwha.evergreen.edu
writes:

>I have a NIB RCA 6L6GC that looks EXACTLY identical (in side by side
>compoarison) to a philips STR387 (dual getter variety). Is it “common
>knowledge” that RCA relabeled some of these?

RCA, Sylvania, GE, Tungsol, Boogie, Fender, Peavy, Groove Tube. I’m sure
there are others. There was lots of swapping among brands. They did have
some identifying characteristics:

RCA – have the tube # in a stop sign shape.
GE – had a series fo dots next to the tube #. (similar to a brail figure)
Sylvania – the tube # is acid etched, not painted. No matter how hard you
rub it, it will not rub off.

Tim

A great amp can make a lousy guitar sound great.
A lousy amp will make a great guitar sound lousy.

From PYLO–(at)–ZTEC.ASU.EDU Mon Jan 27 16:35:20 CST 1997
Article: 36108 of alt.guitar.amps
Path: geraldo.cc.utexas.edu!cs.utexas.edu!ennfs.eas.asu.edu!nntp.dist.maricopa.edu!usenet
From: Dale VanZile
Newsgroups: alt.guitar.amps
Subject: Re: RCA STR387’s??
Date: Mon, 27 Jan 1997 14:05:59 -0700
Organization: Maricopa Community Colleges
Lines: 17
Message-ID: <32ED18A6.672--(at)--ZTEC.ASU.EDU>
References: <854359110.2748--(at)--ejanews.com> <19970127130200.IAA2700--(at)--adder01.news.aol.com>
Reply-To: PYLO–(at)–ZTEC.ASU.EDU
NNTP-Posting-Host: mac42.stu-serv-2.sc.maricopa.edu
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit
X-Mailer: Mozilla 3.0 (Macintosh; I; PPC)

> RCA – have the tube # in a stop sign shape.

Type font is tall and skinny, stop sign is often elongated
in the horizontal direction to make ample room for # on small
tubes (like 12AX7, etc).

> GE – had a series fo dots next to the tube #. (similar to a brail figure)
> Sylvania – the tube # is acid etched, not painted. No matter how hard you
> rub it, it will not rub off.

GE tube # and dots are etched. Slyvania had an ink stamp that
resembled the current “Arial” font available with most word
processor programs. This ink is /very/ difficult to remove
entirely.

Dutch

From jatwoo–(at)–etcom.com Fri Jan 31 20:48:40 CST 1997
Article: 23233 of rec.audio.tubes
Newsgroups: rec.audio.tubes
Path: geraldo.cc.utexas.edu!cs.utexas.edu!howland.erols.net!ix.netcom.com!jatwood
From: jatwoo–(at)–etcom.com (John Atwood)
Subject: Re: Q: sylvania tube origins?
Message-ID:
Organization: Netcom On-Line Services
X-Newsreader: NN version 6.5.0 CURRENT #9
References:
Date: Fri, 31 Jan 1997 19:55:45 GMT
Lines: 56
Sender: jatwoo–(at)–etcom21.netcom.com

krusty writes:

>i noticed that with a bunch of old sylvania tubes i have, the markings
>seem to vary. some have the GE ‘etched’ tube munbers, some have the RCA
>’stop-sign’ marking, and others just have letters…did sylvania groove tubes> just get other makers’ tubes and relabel them? strangley
>enough, i have a bogen pa that has ‘bogen -made by sylvania’ stamped on
>them, so did someone else make them, then sold them to sylvania, who sold
>them to bogen? the lettering on these 7868s are thin letters, written like
>the rca type but just with letters, i’ve seem similar letters on
>tung-sols, but they have a second set of numbers below them. can anyone
>help me out here? thankx….

Sylvania was a major manufacturer of tubes from the 1920s (when they were
called Hygrade Sylvania) until the early 1980’s when their tube line was
bought by Philips ECG. Up until the lates 1950s, they used the octagon
“stop-sign” type marking, although with thinner and more distinct lines than
Tung-Sol or RCA. After that, they used simple type numbers using a font similar
to “Helvetica”. Sylvania probably made more of its own tubes than any other
American tube company, but as with all of them, didn’t make every single type.
Since it was important to provide servicemen and distributors with a complete
line of receiving tubes, all the tube manufacturers had “cross-branding”
agreements. For example, Raytheon developed the 6AH6 in the late 1940s, and
was initially the sole manufacturer. The other tube manufacturers bought or
traded for these Raytheon tubes, but had them marked with their own brand. The
actual tube type number was put on by Raytheon, so by looking at the type
you can identify the brand. (By the way, for the 1940s and early 1950s,
Raytheon minature tubes had their type numbers marked in a circle around the
exhaust tip.) Even when a tube company produced a given type, they
sometimes cross-branded other types if they were short of production capacity.
In the 1970s and ’80s, American companies, particularly Raytheon and RCA,
started cross-branding European and Japanese tubes as they started to shut
down their own production lines. These imports are legitimate in the sense that
they were sanctioned and sold by the original American tube companies. With
the current demand for name-brand American and European N.O.S. tubes, there is
a thriving industry of illegitimate tube counterfeiters who take average
Chinese or military surplus tubes and mark them as Mullards, Telefunkens, RCAs,
etc. Being aware what the originals look like will help you avoid these
counterfeits.

Anyone who has worked with old consumer or industrial tube-based equipment is
aware that many companies had their names marked on their tubes by the tube
company. Again, by looking at the tube type number, the original manufacturer
can be identified, if it is not already indicated on the tube.

By the way, American military-procured tubes (in the white boxes) were never
(to my knowledge) cross-branded. On some, the box may give the name of the
government contractor using the tube, but the tube itself was always branded
by the original manufacturer.

– John Atwood


John Atwood
Preferred e-mail address: atwoo–(at)–ne-electron.com

 

Buy the Book!

I cleaned up my tab for Sonny Boy's Help Me and made it into a short book. There's a Kindle version for 99 cents, and if you buy the paperback you get the Kindle free.

Playing "Help-Me" In the Style of Sonny Boy Williamson II: A step by step, note for note analysis of some of Sonny Boy's Signature Riffs