Sylvania vs westinghouse (short grey plate ID info)

[rockon1]

Finally got a Westinghouse labeled short grey 12AX7 . Since there has been some speculation about these short grey plates with tall square getters being either Sylvania or westinghouse I immediately compared them. The getter wires are virtually identical (as well as the short grey plates) . Thus perhaps the confusion. The big difference that is apparent is in the "stapling" of the plates. The Sylvania on the left in pic has 2 staples while the Westinghouse has 3. Very slight difference at the bottom of the plates too but thats it. Been checking my collection of supposed short grey Sylvanias to find I have a few Westinghouse mixed in-that is if this ID is correct. Heres the pic. Sylvania on left. Westinghouse on right. Still not 100% sure about this but it makes sense . Bob




http://i16.tinypic.com/2po5o9z.jpg

[Timbre Wolf]

I've only seen/possessed one tube that I feel comfortable calling a true Westinghouse, and that is a 12AU7. Does your "Westinghouse" 12AX7 have a series of several dots around the "12AX7" print? These are not GE dots, but a unique pattern that make me think the tube may have been made by Westinghouse, and not just re-labeled by them. Here's a lifted photo of the 12AU7:
http://i16.ebayimg.com/04/i/07/1e/5f/f9_1_b.JPG

If the 12AX7 doesn't have these, then I would be more inclined to believe that both of those 12AX7 styles are Sylvania-made. I do believe that Sylvania made the short gray-plate (in 1957 and perhaps 1958) as a 12AX7 and a 12AX7A, and they may have changed the plate "staples" during that time as well.

- Thom

[rockon1]

I've only seen/possessed one tube that I feel comfortable calling a true Westinghouse, and that is a 12AU7. Does your "Westinghouse" 12AX7 have a series of several dots around the "12AX7" print? These are not GE dots, but a unique pattern that make me think the tube may have been made by Westinghouse, and not just re-labeled by them. Here's a lifted photo of the 12AU7:
http://i16.ebayimg.com/04/i/07/1e/5f/f9_1_b.JPG

If the 12AX7 doesn't have these, then I would be more inclined to believe that both of those 12AX7 styles are Sylvania-made. I do believe that Sylvania made the short gray-plate (in 1957 and perhaps 1958) as a 12AX7 and a 12AX7A, and they may have changed the plate "staples" during that time as well.

- Thom


Ok ,yep, The "westinghouse" does have these dots around the 7025 just as you describe /pictured ! I am much more convinced this is indeed a actual Westinghouse now. Bob

[Timbre Wolf]

Ok ,yep, The "westinghouse" does have these dots around the 7025 just as you describe /pictured ! I am much more convinced this is indeed a actual Westinghouse now. Bob
Me too! Does it sound/perform differently?

[rockon1]

Me too! Does it sound/perform differently?


I'll have to get back to you on that.:BEER Bob

[Anywho]

I have a 12ax7 like this too. It is labelled for motorola, has the unique dot markings, and also has an EIA code of 337 which is the code for Westinghouse.

[Timbre Wolf]

I have a 12ax7 like this too. It is labelled for motorola, has the unique dot markings, and also has an EIA code of 337 which is the code for Westinghouse.
How do you use it? Do you like it?

- T

[rockon1]

Me too! Does it sound/perform differently?



Well I ID'd a few of the Westinghouse (I mislabeled Sylvanias) and Sylvanias went to A/B ing them. I tried them in my Crate VC50 head as the front panel is open and very easy access. I grabbed 2 of each that tested about the same on my eico tester. Somewhat to my surprise I really didnt notice much of a difference between the two. First I replaced the V1 with each and listened to both clean and dirty channels. Then I did the same again with the other two. Then I put the 2 Sylvanias in both V1 and V2 and did then same with the Westinghouse. I only used 2 samples per type but I think I should have noticed some "characteristic" differences none the less.Maybe the amp isnt that responsive to tube changes? Maybe the lag in time between changes affected my ability to judge them? Or maybe they just sound very similar..... YMMV.....FWIW- I prefer the Japanese mullard and JJ I have in it respectively. Im going to try the same in my Rivera when I get a chance.

:BEER Bob

[Timbre Wolf]

Well I ID'd a few of the Westinghouse (I mislabeled Sylvanias) and Sylvanias went to A/B ing them.
Thanks for the research, Bob.

Now, they may be sonically similar, but do you think you could rely on the # of plate holes to i.d. them (Sylvania 2; Westinghouse 3)?

I'm not sure what a Japanese Mullard is (Matsushita?), but I might dub this short gray-plate/square-getter 12AX7 as the American RFT. Its similar to RFT, in my experience, but with somewhat improved clarity. Maybe the "better RFT"?

:BEER &
:BEER

- T

[rockon1]

Thanks for the research, Bob.

Now, they may be sonically similar, but do you think you could rely on the # of plate holes to i.d. them (Sylvania 2; Westinghouse 3)?

I'm not sure what a Japanese Mullard is (Matsushita?), but I might dub this short gray-plate/square-getter 12AX7 as the American RFT. Its similar to RFT, in my experience, but with somewhat improved clarity. Maybe the "better RFT"?

:BEER &
:BEER

- T


(Yes a matsushita) Anyhow.....To answer the ID question-no! Try and follow this closely....I just dug out some more Slyvania labeled short greys and low and behold a couple of the had 3 holes! These Sylvanias DID NOT have the supposed Westinghouse dots around the 12AX7 ecthing. ALL of these Sylvanias with no dots around the etching whether 3 or 2 hole have copper support rods. All the "Westinghouse" (and I say that loosely at this point) with the dots around the 12AX7 have steel support rods. On one of these -a Philco labeled one- there is the 337 paint code on it....Confused yet?...Whats the deal ? This is not as cut and dry as I hoped it would be! Bob

[Timbre Wolf]

Tubemonger seems to be the most knowledgeable in terms of tube manufacturers and their historical associations. I would love to hear Tubemonger's input on this thread, but they seem to be more active in the HiFi realm (Tubes Asylum). Tubemonger has sold each version, and has identified them as separate and distinct Sylvania and Westinghouse tubes.

This is about as far as I can go with this topic, though, since I don't have any Westinghouse versions of this tube to compare. It seems it is sonically similar enough for me not to pursue, for my purposes, since I've already got the Sylvanias. Interesting blurring of identities, though.

- Thom

[rockon1]

Tubemonger seems to be the most knowledgeable in terms of tube manufacturers and their historical associations. I would love to hear Tubemonger's input on this thread, but they seem to be more active in the HiFi realm (Tubes Asylum). Tubemonger has sold each version, and has identified them as separate and distinct Sylvania and Westinghouse tubes.

This is about as far as I can go with this topic, though, since I don't have any Westinghouse versions of this tube to compare. It seems it is sonically similar enough for me not to pursue, for my purposes, since I've already got the Sylvanias. Interesting blurring of identities, though.

- Thom


Yeah,thats what drives me a bit nuts. The 'blurring" of idenities! There must be something behind the commonality of these tubes. Ive reboxed all mine and thats about that I guess! Bob

[rockon1]

Tubemonger seems to be the most knowledgeable in terms of tube manufacturers and their historical associations. I would love to hear Tubemonger's input on this thread,


Thom ,you may get your wish, Bob;)

[tubemonger]

One with the several small dots is Westinghouse made. Early American made tubes get very confusing with similarities in the plate structures but there are subtle differences. There were a lot of Westinghouse Canada 12AX7 tubes also and these have Canada printed on the tubes (see examples in the pic lib link below).

http://69.36.182.51/tube%20pics/1960s%20Westinghouse%2012AX7%20SQ%20GT.jpg
Here is a pic of the 1960s Westinghouse 12AX7 tubes.

You can see more tube pictures at the following link:
http://www.tubemonger.com/NOS%20Tubes%20Picture%20Library/index.html

If you need any tubes please contact Tubetramp first.

[rockon1]

Tubemonger thanks for responding!(and pardon my manners,welcome to TGP!) Heres a pic of a Westinghouse on the left(has dots around 12AX7 etching) and a Sylvania (more typical 12AX7 etching)on the right. Plate contruction is identical as is the getter wire. The ONLy difference I see is copper supprt posts on the sylvania. Both these have three fastening holes in plates-the reflection is blocking the veiw of the two on the left.One would think they were made in the same factory!Either that or one company "borrowed" the design from the other.... Bob


http://i17.tinypic.com/47hv4f6.jpg

[Timbre Wolf]

Thanks for joining in here, Tubemonger - let me offer you a hearty WELCOME to the Gear Page!! :D I've always appreciated your comments on i.d.-ing tubes at the Tubes Asylum, and I'm glad Bob invited you (presumably - thanks Bob) to jump in here.

I've found that Westinghouse mostly re-branded tubes (even putting their EIA of 337 on them), but there are a few examples that seem well and truly made by them. I particularly enjoy Westinghouse's black-plate 12AU7. Now there's this 12AX7, which is almost identical to the Sylvania (some of which I've bought from you, Tubemonger!).

I'm curious - what is the connection to Tubetramp? I've bought tubes from your business, via the excellent web-site, but I don't know who Tubetramp is or how to contact him. Can you elaborate on this connection, please?

- Thom

[tubemonger]

Tubemonger thanks for responding!(and pardon my manners,welcome to TGP!) Heres a pic of a Westinghouse on the left(has dots around 12AX7 etching) and a Sylvania (more typical 12AX7 etching)on the right. Plate contruction is identical as is the getter wire. The ONLy difference I see is copper supprt posts on the sylvania. Both these have three fastening holes in plates-the reflection is blocking the veiw of the two on the left.One would think they were made in the same factory!Either that or one company "borrowed" the design from the other.... Bob


http://i17.tinypic.com/47hv4f6.jpg

Thanks!Tube bottles are totally different and are not from the same plant. There are numerous examples of very similar looking plates on tubes from 1950s-1960s. It was also common for some companies to source internals from others (more common with Philips companies) with evacuation done somewhere else. For example, some of the CBS/Hytron tubes look identical to the Raytheons. Your guess is right that these could be result of collaboration or just plain copying. Electronics industry always thrived in these modes. Similar behavior was very common in early Silicon Valley days when key engineers would be enticed by competitors or branch off to create startups resulting in cross pollination of ideas.

[tubemonger]

Tubetramp (terry_kilgore2003 use at sign here yahoo.com) sells tubes and has considerable experience with Guitar Amps and tone related issues. Perhaps someone else can chime in and give additional details on his experience. We have shared stock with him at times. None of us at tubemonger can give any tone related advice since we dont have any musicians in house.

[Timbre Wolf]

None of us at tubemonger can give any tone related advice since we dont have any musicians in house.
That's okay - if you can help us elucidate the "what it is" side of tube topics, now and then, that's a big help. Several others of us can address the "how does it perform" side of the topics, and keep arguing those fine points far into the night.

- Thom

p.s. I'm just a few miles north of you. Let me know if you need a musician's point of view on your fine tubes, and I'll be right there!! ;)

[rockon1]

Thanks!Tube bottles are totally different and are not from the same plant. There are numerous examples of very similar looking plates on tubes from 1950s-1960s. It was also common for some companies to source internals from others (more common with Philips companies) with evacuation done somewhere else. For example, some of the CBS/Hytron tubes look identical to the Raytheons. Your guess is right that these could be result of collaboration or just plain copying. Electronics industry always thrived in these modes. Similar behavior was very common in early Silicon Valley days when key engineers would be enticed by competitors or branch off to create startups resulting in cross pollination of ideas.

Its been only about a year since I delved into the old stock 12AX7 world. In that time Ive purchased hundreds of them. Thanks to help from guys like you,and various members on this board (Timbre Wolf,Blue strat and others)Ive gathered a lot of information on 12AX7 tube ID and history. I can now ID many at a glance. When I run across similar tubes as these it peaks my curiosity and desire to learn more.
Speaking of Philips innards - I have a few Raytheon branded (and etched) 12AX7's I swear have Mullard short plate guts in them -a US Mullard so to speak! Anyhow thanks again for talking the time to share your expertise with us.

:BEER Bob

[rockon1]

That's okay - if you can help us elucidate the "what it is" side of tube topics, now and then, that's a big help. Several others of us can address the "how does it perform" side of the topics, and keep arguing those fine points far into the night.

Cheers!

- Thom

+1000! :BEER Bob

[Anywho]

Sorry I lost track of this thread. Anyway, the one westinghouse-ish looking tube was microphonic in V1 and only held up in the PI. I haven't really done much tone testing with it and at the time I was using it I probably thought it was a GE short plate or a Sylvania. Roughly speaking, I would group it in with the Sylvania or Matsu's having more of an upper mid... or what I call a ratty sound... little bit more peaky and snarl. I also wanted to pass along that I've read alot of the Raytheon stuff was imported from Japan.

[Timbre Wolf]

I've read alot of the Raytheon stuff was imported from Japan.
Raytheon outsourced some of their vacuum tube production (12AX7, at least) to Japan beginning in 1962, as far as I can tell.

- Thom

[Timbre Wolf]

Well, I finally got hold of some short gray-plate/square-getter Westinghouse 12AX7 (or 7025). I'm now more convinced that Westinghouse did indeed produce their own version of these tubes, but that they probably used Sylvania-made plates and getter wire assembly. Here are some pics:

1963 Westinghouse (with 337 EIA code) on left, 1957 Sylvania on right. Note the same getter wire design, both with copper support posts, but mounted on mirror-image corners. The micas are similar (but not exact) - the Sylvania has a thicker (double?) upper-mica.
http://i138.photobucket.com/albums/q248/opalize/West-Syl-2.jpg

Here's a better view of the upper micas; note that the Westinghouse (left) has tiny alignment holes that the Sylvania does not have. I believe that Westinghouse made their own version of this mica, but based it on the original Sylvania design.
http://i138.photobucket.com/albums/q248/opalize/West-Syl-3.jpg

[Timbre Wolf]

Here is a final, bottom view. You can better see how the Westinghouse (left) mica cuts are shorter and thicker than the Sylvania, but are of the same general design:
http://i138.photobucket.com/albums/q248/opalize/West-Syl-4.jpg

Though I didn't show it, one of my Westinghouse tubes has the Westinghouse-style etched dots around the "7025" number, as further weight to the Westinghouse ID theory.

Now here's the clincher: neither of my two Westinghouse examples have the early-breakup character that is so appealing in the Sylvania gray-plate version! In fact, without this character, it is a rather ho-hum tube.

So here is my working theory on these tube types:
Sylvania had un-assembled overstock of the plates and getter wires when they changed from short- to long-plate 12AX7 production in 1958. Westinghouse purchased these materials 4-5 years later, likely at a bargain price. Westinghouse had to create their own micas to use with the plates, and used their own glass envelopes as well (and possibly cathode/heater/grid).

I'm sure that few others besides Bob (Rockon1) and I much care about these minutiae, but it is good to have at least one other friend in one's line of obsession. :)

- Thom

[Trout]

Tubemonger thanks for responding!(and pardon my manners,welcome to TGP!) Heres a pic of a Westinghouse on the left(has dots around 12AX7 etching) and a Sylvania (more typical 12AX7 etching)on the right. Plate contruction is identical as is the getter wire. The ONLy difference I see is copper supprt posts on the sylvania. Both these have three fastening holes in plates-the reflection is blocking the veiw of the two on the left.One would think they were made in the same factory!Either that or one company "borrowed" the design from the other.... Bob


http://i17.tinypic.com/47hv4f6.jpg

Interesting,

I have an NOS Westinghouse here on an original hang tagger.
I got a whole Westinghouse table top display a few years back. I had the luck of getting a couple dozen of these.
Square/rectangular getter wire.

http://home.mchsi.com/~my_mcintosh_240/west12ax7.JPG

[Timbre Wolf]

I have an NOS Westinghouse here on an original hang tagger.
That's the one we're talking about, Trout! Cool collectible!! Thanks for posting.

Note their slogan: You can be sure...if it's Westinghouse Hah!! you can usually bet that it is re-branded, if it says Westinghouse. In this case, it is Westinghouse (at least partially), thus proving that you can be sure of nothing, when it comes to "Westinghouse." :jo Even this 12AX7 was sold as 12AX7, 12AX7A, and 7025.

- T

[rockon1]

Thom- I didnt notice much difference in the tonal qualities of these two tubes. I have come to regard them as interchangable tone-wise. Of coarse detecting early break up isnt my strong suit as most of my playing and testing is done medium to high gain. Interesting that they do indeed have differences in break up though.

I think yes its probable that Sylvania supplied the internals to Westinghouse. Now what about the 2 hole versions? And why switch from 2 to 3 holes or vice versa?..... lol! This we may never know! Nice pics BTW !

Im still rambling over the Raytheon short plate thing....-Bob

One more thing..... This pic with the Webcor (Westinghouse dots) has the getter on the same post as the Sylvania....

http://i17.tinypic.com/47hv4f6.jpg

[Timbre Wolf]

Thom- I didnt notice much difference in the tonal qualities of these two tubes. I have come to regard them as interchangable tone-wise. Of coarse detecting early break up isnt my strong suit as most of my playing and testing is done medium to high gain. Interesting that they do indeed have differences in break up though.
I only have two of the Westinghouse versions, so it is not a large enough sample to generalize - especially without rigorous performance testing on the tubes. Just something I noticed with these two, though.

Now what about the 2 hole versions? And why switch from 2 to 3 holes or vice versa?..... lol! This we may never know! Nice pics BTW !
Seems the Westinghouse are 3-hole... yes? So the switch would have been from 2-hole to three hole, if the theory that Westinghouse bought Sylvania leftovers is true. I would guess that Sylvania discovered these are unstable with two holes only, perhaps? A glance at my black-plate versions (older, 1956 production) supports this theory:

http://i138.photobucket.com/albums/q248/opalize/SylvaniaShortBlack-Plate12AX7.jpg

...now they know how many holes it takes to fill the Albert Hall...

[rockon1]

Your 2 to 3 hole theory sounds reasonable.

On a side note- I recently rediscovered(or perhaps discovered) the Sylvania triple mica 5751 black plate. Looking for something to put in the extra gain stages(V2) of my Peavey I figured I'd give it a try.Very nice fit! It seemed to add just a bit of chewy texture to the OD channels while reducing the abudent mids slightly. Figures its one of few tubes I only have 3 of! Well I probably only need the one and it should last a long time. Bob

[Trout]

Whats is your take on these sylvania long plate versions?

They have an etched ECC83 and 12AX7, but no etched dots like a GE, and no dots like the westinghouses.

A similar plate style, but much taller.

http://home.mchsi.com/~my_mcintosh_240/syl1.JPG

[Timbre Wolf]

Whats is your take on these sylvania long plate versions?
Those long gray-plate Sylvania 12AX7A have unique plates that no other manufacturer used, so you won't find dots etched onto the glass. Sylvania moved to this style production in around 1958, immediately after the short gray-plate style.

I find them to be too murky to be of use for my taste. I certainly wouldn't recommend them for V1 of any amp. A lot of people like them as a second gain stage tube, and I would agree with this use, since that typically is where you want more overdrive and compression.

If you want to get some for less $$, then search eBay for Baldwin 12AX7. The Baldwin organ company often used those Sylvania tubes for their go-to valve. They also sometimes used RCA, Raytheon, and even GE, but you can always tell the Sylvania by the plates.

- T

[rockon1]

Those long gray-plate Sylvania 12AX7A have unique plates that no other manufacturer used, so you won't find dots etched onto the glass. Sylvania moved to this style production in around 1958, immediately after the short gray-plate style.

I find them to be too murky to be of use for my taste. I certainly wouldn't recommend them for V1 of any amp. A lot of people like them as a second gain stage tube, and I would agree with this use, since that typically is where you want more overdrive and compression.

If you want to get some for less $$, then search eBay for Baldwin 12AX7. The Baldwin organ company often used those Sylvania tubes for their go-to valve. They also sometimes used RCA, Raytheon, and even GE, but you can always tell the Sylvania by the plates.

- T

Agreed. These LP Sylvania's are too indisticnt even for my medium to high gain tastes. Bob

[bunuel]

-1! Respectfully disagree about the sylvania longplates. I'm not generally keen on using longplate 12ax7 in any of my amps in V1 because of noise issues, but I really like the sylvania longplates (generally) in my many single-ended champlike amps because they're very quiet for a longplate but serve up sweet & detailed gain, which is all I'm looking for in those particular amps. They're also my go-to in v2, etc. for the reasons already discussed. In my amps with my axes, the sylv. 12ax7 longplates are easily among my favorites: I've had more than a few that I like better than my t-funkens, mullards, or any of the better OS US tubes, though I hold on to those, too, because they've got their uses. Luckily, tastes vary (or I wouldn't be able to pick up OS Sylvania 12ax7 for 1/20 of the cost of there mullard equivalents, which suites me perfectly).

[rockon1]

Interesting . What you describe sounds more like a Sylvania black plate which have much more detail and clarity than the long gray plates IMO. Bob

[bunuel]

I was describing the Sylvania long gray plates in my prev. post...very nice gain & very sweet, yet unnoisy, in my several of my ol' champlike single ended amps (Danos & Valcos). I generally agree that the Sylv. blackplates are very nice & a bit more consistently detailed in my exp. I often go w/ 'em in V1 in my amps w. multiple preamp slots.

That said, I've got a more than few long grey plate sylvanias that are wonderfully crisp & detailed. Perhaps my fave affordable OS long plate 12ax7.