I bought some 12AU7 tubes which were sold as genuine, but I'm having doubts after seeing the tube.
Pictures of the tube:
Pictures of the tube:
The printing on the glass looks like modern ink. I washed the tube with soap and water and the printing did not come off. Every other tube I've ever had, the printing did not survive a cleaning.
There is also no etched date code or any other marking on the glass other than the ink lettering.
p.s. The pictures appear vertically squished, but if you click on the picture it will display properly.
There is also no etched date code or any other marking on the glass other than the ink lettering.
p.s. The pictures appear vertically squished, but if you click on the picture it will display properly.
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Hi,
The fact that the printing does not wash off does not tell you much other than that old European valves used calcium based ink that did rub of easily.
OTOH, the fact that there's no acid engraving on the glass envelope ( there normally always is at least some code on it) should tell you that the valve is not made in the USA.
This is not uncommon since most of the Philips plants were all over the world and at the end of the valve era product was often traded inside these groups of manufacturers.
Going by the pics I'd say those are probably Sylvania/ECG but it's anybody's guess.
Cheers, 😉
The fact that the printing does not wash off does not tell you much other than that old European valves used calcium based ink that did rub of easily.
OTOH, the fact that there's no acid engraving on the glass envelope ( there normally always is at least some code on it) should tell you that the valve is not made in the USA.
This is not uncommon since most of the Philips plants were all over the world and at the end of the valve era product was often traded inside these groups of manufacturers.
Going by the pics I'd say those are probably Sylvania/ECG but it's anybody's guess.
Cheers, 😉
It does look sloppily stamped. The "Electronic" looks like GE made it, but it doesn't have a manufacturer stamp, that makes it look like a second, or they cleaned a used tube, the lettering came off and they restamped it.
Anode looks kinda like a Sylvania.
Anode looks kinda like a Sylvania.
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Old authentic GE made tubes had etched stencil markings on the glass. They are likely remarked, just not sure by who. I prefer NOS 5814A tubes, preferably the old broadcast series, i.e., RCA Command or GE 5-star tubes. Sylvania tubes are generally excellent as well.
Regards,
KM
Regards,
KM
Doesn't look like any GE 12AU7 tubes I have:
1. GE manufactured tubes virtually always have the type etched into the glass (along with a pattern of dots), usually/often in addition to it being printed
2. The plate structure is different than the tubes I have (3 ribs on mine)
Now, all that does not mean necessarily that the seller relabeled them - there was a lot of re-selling and re-labeling being done by the manufacturers themselves, especially towards the end of production. But I don't think this is what most would consider a typical US GE 12AU7...
Pete
1. GE manufactured tubes virtually always have the type etched into the glass (along with a pattern of dots), usually/often in addition to it being printed
2. The plate structure is different than the tubes I have (3 ribs on mine)
Now, all that does not mean necessarily that the seller relabeled them - there was a lot of re-selling and re-labeling being done by the manufacturers themselves, especially towards the end of production. But I don't think this is what most would consider a typical US GE 12AU7...
Pete
I don't think anyone would pay for modern 12AU7's and spend the money/time to reprint on them and then sell them because NOS 12AU7's don't fetch any big money from what I have seen.
I have tons of American brand 12AU7's here are some pics. Like Pete said all of my GE's have 3 ribs.
In order;
Tung-Sol 12AU7A
GE white label 12AU7 horseshoe getter
GE made for CBS 12AU7
Sylvania 6189/12AU7WA
Unkown USA gold pins 12AU7A
Sylvania green label 12AU7A square getter
I can dig more out.
I have tons of American brand 12AU7's here are some pics. Like Pete said all of my GE's have 3 ribs.
In order;
Tung-Sol 12AU7A
GE white label 12AU7 horseshoe getter
GE made for CBS 12AU7
Sylvania 6189/12AU7WA
Unkown USA gold pins 12AU7A
Sylvania green label 12AU7A square getter
I can dig more out.
Attachments
I suppose the question revolves around what he paid for them based on what he thought they were.
I dug through my stash of old and used tubes and found what looks like a very close match in terms of the getter and plate structure. I would guess that the ones the OP posted are relabeled late Sylvania or Philips ECG.. Not bad tubes..
I have attached two macros of the sample I found in my collection.
See post #7 - I think this is as likely an explanation as any. The ink Philips ECG used on the last few years of production is pretty durable.
I dug through my stash of old and used tubes and found what looks like a very close match in terms of the getter and plate structure. I would guess that the ones the OP posted are relabeled late Sylvania or Philips ECG.. Not bad tubes..
I have attached two macros of the sample I found in my collection.
See post #7 - I think this is as likely an explanation as any. The ink Philips ECG used on the last few years of production is pretty durable.
Attachments
The million dollar question: does it matter?
FWIW I'd care about emission, transconductance/gain and microphonics, rather about what a label says or the ink used.
Or the amount of ribs.
FWIW I'd care about emission, transconductance/gain and microphonics, rather about what a label says or the ink used.
Or the amount of ribs.
Again it is a matter of what he paid, and what he expected to get. Hopefully he was promised nothing more than late American made 12AU7A in which case he basically got what he paid for.
Years ago I purchased a bunch of Amperex 12AU7A/ECC82 from a seller in Hong Kong, the first batch were exactly as represented and were made in Holland, the second batch were Richardson relabels and I paid the same money for them with the expectation that I was getting the same thing - only I did not, and this was not disclosed anywhere by the seller on ePray.. A clear case of misrepresentation, and I paid $20 a tube when the going rate for the Sylvania tube they sent me was about $6.00.
Edit: I should mention that the Amperex tubes both measured somewhat quieter and more linear than the Sylvania example which is why I was paying the premium for them. Not all 12AU7A/ECC82 were created equal.
Years ago I purchased a bunch of Amperex 12AU7A/ECC82 from a seller in Hong Kong, the first batch were exactly as represented and were made in Holland, the second batch were Richardson relabels and I paid the same money for them with the expectation that I was getting the same thing - only I did not, and this was not disclosed anywhere by the seller on ePray.. A clear case of misrepresentation, and I paid $20 a tube when the going rate for the Sylvania tube they sent me was about $6.00.
Edit: I should mention that the Amperex tubes both measured somewhat quieter and more linear than the Sylvania example which is why I was paying the premium for them. Not all 12AU7A/ECC82 were created equal.
I agree that nobody would go to the trouble of counterfeiting a 12au7.
I only have a couple GE 12au7 types and yes they have 3 ribs.
Here, however, are three Sylvania with 2 ribs:
An externally hosted image should be here but it was not working when we last tested it.
Technically there's a 12au7, a 12au7a, and a 5963
If it works and sounds good, use it. If you paid a lot of money for it, people are paying a lot of money for ge 12au7? at any rate, yes it looks like a usa-made 12au7 type to me.
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I have not bought 12AU7A in over a decade now, the prices seem to have dropped significantly which IMHO is a great thing..
Thank you for all the replies! I've learned a lot from reading them.
I asked the question because I wanted to know exactly what I've got. I didn't set out to buy GE specifically, I just wanted good tubes but I don't like having mislabeled tubes.
I asked the question because I wanted to know exactly what I've got. I didn't set out to buy GE specifically, I just wanted good tubes but I don't like having mislabeled tubes.
Hard to tell from just pictures but it looks like you got some Philips ECG, which are great tubes IMHO, so in this case even though you didn't get GE you still got some darn good tubes🙂
The fact is has ECC82 written on it gives me the impression it was a european sourced tube. I know it sounds silly, but i always found Philips tubes have very clear glass, especially around the base, the OP's pictures have that look to me.
From the plate structure, I'm 99.998% sure it's a Sylvania/ECG Philips. I've held, touched, fondled untold quantities in my days as a TV tech.
Hi,
Could be coming from one of the many plants based in India as well.
Guessing's fun, isn't it? 😀
Cheers, 😉
Could be coming from one of the many plants based in India as well.
Guessing's fun, isn't it? 😀
Cheers, 😉
Philips (old Sylvania) would be my guess as well - some of the last tubes made in the US. Earlier GEs would have had the large etched number and dots as mentioned. But when GE relabeled tubes, they would never ID the actual maker. I have Mullard, RCA, Sylvania tubes relabeled GE - they all have the 188-5 code (GE, Kentucky).
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