Tungsram 12AX7?

[sgtoverdrive]

the tube you keep pointing to is definetly not a tungsram ,this is an rft erfurt munich manufacture ,and one of the best v1 tubes that can be had.i have slews of them in most cases .they have become scarce .wonderful tube and tungsram had there roots in england i have english tungsrams .but any tungsram will do! sgt overdrive/

[Twister]

FYI, Tungsrams made in Hungry actually were made the best during the mid-late 70s'. The earlier Tungsrams were really good, but they got it the best around 1977. That goes against the grain of just about every other tube manufacturer.......the earlier, the better it was made.

Also, Mullard took over management of British Tungsram in 1952, and it's not a coincidence that whenever you see an ECC83 in a yellow/red British Tungsram box, its a Blackburn made Mullard with a Tungsram logo on it.

[dotfret]

When it comes to marks of origin on valves, it was and is definitely illegal
to sell them in US marked with an incorrect origin. In GB the designation "Foreign" was an alternative to actually stating the country of origin. "GB", "UK" or "Empire" made were for British goods - this system was actually obsolete in the 30s, but was carried on for a long time. I have actually seen valves marked Foreign that were made in France by one company, transported to England for labelling, then sent back to France for sale by the label company!

Here is the short history that I have researched. It may not be entirely accurate, but it is the best I can find -

British Tungsram was founded as a subsidiary of the Hungarian company in 1933. They did not join the British Valve Manufacturers Association (BVA), and were selling replacement valves exclusively to the trade market through (British) Siemens. When WWII started in 1939, the Tottenham plant was not a full manufacturing facility, but was assembling Hungarian made components into valves (Philips Australia used to work this way, too). By the end of the war it had become a full-blown manufacturing facility because of the demands of wartime production. In 1952 Philips acquired the business, and installed management from Mullard, but the Tungsram sales were still tied into Siemens. By 1956 the Siemens valve business had been sold into the AEI group, who were working under the manufacturing name of Siemens Edison Swan and marketing their valves both as Ediswan and English Mazda - they did not want to sell the competition's valves, although under the trading agreements they were obliged to do so. Philips could not expand the business, presumably because of the trading agreements with Siemens, so in April 1956 they closed the Tottenham Tungsram factory and supplied the Tungsram demands with Mullard stock. After a decent interval, to let the trade agreements die, the factory was re-opened as a Philips/Mullard subsidiary, then fell victim to the transistor. But somewhere along the line there was another door, and England was still being supplied with Hungarian valves in red and yellow boxes!

And it is not just true of Tungsram that the best came at the end- the best
Mullards were 70s production, if you look at signal/noise (M8137!) and the best from Telefunken and Brimar came right at the end of production (Telefunken EF806S and Brimar ECC807, as examples).

That is the best I can do...

[Twister]

The best Mullards were 70's production? Wow! I'm speechless. OK, that's the first time I've heard that opinion. And I totally disagree about Telefunken and Brimar too. There were certainly good tubes made at the end of some companies, but the budget cuts to stay competitve hurt the quality starting in the late 60's and going throughout the 70's and 80's. That's a well documented fact.

Regarding the Made In the USA, it may have been against the law, but it was broken all the time and apparently not enforced. How many times do you see a Japanese made tube with a USA stamp on it? All the time.

[dotfret]

It does depend on what you are looking for with Mullards - if you want the typical Mullard ECC83 sound in your guitar amp, you want old longplate valves. The M8137 is a low-noise shortplate - the point is that it took very good QA to produce a run. Most manufacturers would have been picking out the good ones and marking them M8137, whereas Mullard were picking out the bad ones and marking them ECC83. Mullard were the best quality in UK - I have seen a UK government report that showed Mullard to have a lower failure rate and longer life than the other UK manufacturers.

Telefunken made good stuff right up to the end - the complaints came when they stopped making their own and bought them in from other sources, like East German production. Brimar didn't get the chance to fight to stay alive - Standard pulled the plug on them - they didn't drop their quality. GEC-MOV got their plug pulled too, just when Marshall had changed their designs to accommodate using KT77 instead of EL34.

I have never seen a Japanese valve marked Made in USA. We had very few US or Japanese valves in GB anyway - import tariffs into Europe were very high, so there was no reason to bring them in when local production was good quality and cheaper. The tariffs were also why the Japanese built their European market TVs in Wales- they brought componentry in to do that, because they could avoid the import tariffs that way, and that was the main source of Japanese valves in GB.

[Twister]

With all due respect, you really need to go re-study Mullard tubes and their designations. The Mullard M8137 has nothing to do with a Mullard ECC83.....completely different tube. An M8137 (CV4004) is a low noise box plate design. The plates are nothing like the Mullard ECC83, and the sonic character is completely different.

So obviously Mullard didn't take the bad M8137/CV4004 and label them ECC83. It sounds like you're just making this stuff up.

Of course the original great manufacturers such as Mullard, Brimar, Telefunken, etc. made better tubes than the later manufacturers EI and JJ. That's not what we're even talking about. The point is that the original great manufacturers all suffered from decline in quality starting in the late 60's because of cost cutting to stay competitive in the market. There's no debate on that, it happened, it's a well documented fact.

[zaphod_phil]

I wouldn't be so hasty throw accustaions like that around!

However AFAIK the M8137/CV4004 is sometomes said to sound somewhat sterile for use in guitar amps, compared to the "regular" Mullard ECC83s, and are therefore better suited to hi-fi. This tends to suggest that they are indeed different valves inside the glass.

This test report from Watford Valves points out the audio/hi-fi benefits of the M8137/C4004 - http://www.watfordvalves.com/cgi-bin/do ... port_2.pdf

[Twister]

I've been reading a lot of his posts and it's a trend I see. I don't like souding harsh or being confrontational, but BS'ers need to be called out so they don't mislead people that are trying to learn about tubes.

Here's a pic of a Mullard M8137/CV4004. Notice the two big fat rectangular plates:



Here's a regular 14mm Mullard shortplate next to a M8137/CV4004. scroll down to the second photo and look at the first two tubes:

http://www.cathedralstone.net/Pages/TelefunkenECC83.htm

They sound different because they're a very different design.

[dotfret]

Yes, Twister, the M8137 is a different design to the standard Philips 12AX7 designs. That is a picture of an old one - it went through a couple more modifications before production ceased. And for some strange reason, all the M8137 types fit the ECC83 specification. I have seen some curious versions of the ECC83 over the years. I suppose you would say I was dreaming if I told you of a clear top version? No - you would just say that it was not an ECC83 ... someone must have written it on another valve.

I think that, with your criticisms and insults, you seek to deflect attention away from the fact that you are wrong about quality dropping at the end of GB valve production.

What is your next piece of nit-picking going to be? You could tell me that a "fat boy" 6CA7 is not an EL34, if you need an idea.

[zaphod_phil]

I don't like souding harsh or being confrontational, but BS'ers need to be called out so they don't mislead people that are trying to learn about tubes.

You're welcome to have your differences of opinion. I don't always agree with Dotfret myself. However, your rude and aggressive approach is not permitted on this BBS, if you read the rules. Please either edit your previous posts or find somewhere else to insult people.

[Twister]

I think that a couple of people are a bit sensitive. If someone is giving out wrong info., it needs to be corrected plain and simple. I'm not upset about the quality issue. That didn't come from me. It came from numerous publications, articles, interviews of old tube engineers, etc. Ask any tube guru old timer. That's how I formed my opinion, based on what they said. If you disagree with all of them, that's fine. But you're still wrong.

The Mullard M8137/CV4004 has always been a box plate tube per the above pic which is a completely different sounding tube and different design. Slight changes or not, it's still the same box plate design. You had said that Mullard probably took the bad M8137/CV4004's and used them as regular ECC83's......and my point was that it's impossible....it's not an ECC83 philips shortplate 83. That's my point. Have you ever seen a box plate labeled as a Mullard ECC83? I never have in many years, and I'd love to see one if there was. Do you got a pic? The point is that it wasn't common practice, you'd see it often.