[bcowen]

Closets, basements, garages and stuff. The limited supply ran out a long time ago. It seems tubes last a long time but they do have a lifespan. The repair shops went out of business people bought up their stock probably back in the 70s, 80s and 90s? Then in the 90s-2000s, i’d take a guess that lot of people were buying a lot of tubes up when the price seemed fair enough to collect multiples as spares for a lifetime supply as they knew the demand should only increase. If you were the betting man, you’d be right. Although digital back then was exciting enough to make you consider selling off your vinyl collection (and then regret it). And well today some of these tube owners are selling them off at a much higher market price. I get pretty damn excited if I find a desirable true nos tube nowadays.

The '80's and early '90's were great times to buy tubes (and vinyl). Big lots of some very desirable tubes being sold off for cheap. I remember buying 50 Cifte (Mazda) 12AU7's for $100. These days they go for $100 each. 30 Mullard CV4033's for $50. The first reissue of the WE 300B's were $400 a pair. Even GEC KT-77's for $40 each. Just wish I'd waited until now to sell all those.

Nobody wanted Russian tubes because that sound was identified with the Sovtek-branded crap being manufactured at the time. Wish I'd bought a few thousand Melz 1578's back then...

 

[jonathan c]

Unless it’s a short If it’s a GE, then it's just not worth the risk of putting it back in your amp IMO, at least not for the average any user. Sometimes it's not just the fuse that blows sucks.

FTFY…[Reg. TM; © bcowen: 2021]

 

[mordy]

I always wanted to have all red tubes - don't know why; maybe because they are pretty and look different than anything else.. In any case, here is a pair of red Mullard EF39 tubes. These are from the 6J7 family from which the 6C5 was derived.

At first I thought that these tubes are metal such as the US made 6J7 but they are made out of glass and probably covered with some kind of RFI coating.
Maybe somebody can help me with the coding and dates? - I am stumped:

Each tube has the markings 1002 and underneath 2 F O (or 0?).
Here is a useful post about British markings: https://mullard.org/blogs/news/83886851-cv-numbers-and-uk-military-date-and-factory-codes
but in this case I don't know if it helps. F could be a factory code or a month; 2 could be a year?
Here is another post - unfortunately none of the links quoted work:
https://www.radiomuseum.org/forum/ef39_ef39.html
It seems that 1002 is another designation for EF39.
Taking a uneducated guess if would venture to say that these tubes were made in 1950-52?
In any case, this pair of 0.2A tubes sound very nice with 6 x 6N12S i my amp. Mullard nice.

 

[whirlwind]

I always wanted to have all red tubes - don't know why; maybe because they are pretty and look different than anything else.. In any case, here is a pair of red Mullard EF39 tubes. These are from the 6J7 family from which the 6C5 was derived.

At first I thought that these tubes are metal such as the US made 6J7 but they are made out of glass and probably covered with some kind of RFI coating.
Maybe somebody can help me with the coding and dates? - I am stumped:

Each tube has the markings 1002 and underneath 2 F O (or 0?).
Here is a useful post about British markings: https://mullard.org/blogs/news/83886851-cv-numbers-and-uk-military-date-and-factory-codes
but in this case I don't know if it helps. F could be a factory code or a month; 2 could be a year?
Here is another post - unfortunately none of the links quoted work:
https://www.radiomuseum.org/forum/ef39_ef39.html
It seems that 1002 is another designation for EF39.
Taking a uneducated guess if would venture to say that these tubes were made in 1950-52?
In any case, this pair of 0.2A tubes sound very nice with 6 x 6N12S i my amp. Mullard nice.

Those are sexy!

 

[triod750]

Some more history: https://www.dos4ever.com/EF50/PTT_okt_1946_large_eng.pdf
Not a 6J5 in sight - beware!

 

[triod750]

Bombing of Philips facilities in Eindhoven during the war:

 

[bcowen]

Bombing of Philips facilities in Eindhoven during the war:

Um, Eindhoven is in the Netherlands. While there was a lot of damage done in eastern Holland from Allied bombers being off target, I kinda doubt they would have made a video about it with the pilot(s) smiling.

 

[triod750]

Um, Eindhoven is in the Netherlands. While there was a lot of damage done in eastern Holland from Allied bombers being off target, I kinda doubt they would have made a video about it with the pilot(s) smiling.

He might have been a daredevil!

 

[mordy]

Bombing of Philips facilities in Eindhoven during the war:

https://en.wikipedia.org/wiki/Operation_Oyster
Above is a link to a detailed account of the bombing raids of the Dutch Philips radio and tube factories in Eindhoven and nearby. According to this account, production was halted for around 6 months in the middle of the war.
The allied bombing was considered a huge success and involved a massive coordinated operation.

 

[triod750]

Thanks, Mordy.

 

[jonathan c]

https://en.wikipedia.org/wiki/Operation_Oyster
Above is a link to a detailed account of the bombing raids of the Dutch Philips radio and tube factories in Eindhoven and nearby. According to this account, production was halted for around 6 months in the middle of the war.
The allied bombing was considered a huge success and involved a massive coordinated operation.

Also, this:

 

[triod750]

Now we know what happened to some of the tubes from yesteryear. Hoarding isn't the full explanation.

And keeping museum pieces is a noble thing to do....

 

[leftside]

I have some Philips wartime 4654 tubes with the nazi symbols. I need to check and see if they were made in the Eindhoven factory.

I love a bit of history - one of the reasons for my fascination with old tubes and why I read the old books by Philips, Marconi, etc. I treat many of these old tubes as historical museum artifacts.

 

[jonathan c]

Now we know what happened to some of the tubes from yesteryear. Hoarding isn't the full explanation.

And keeping museum pieces is a noble thing to do....

…@bcowen will enjoy nobility……the Earl of Eindhoven…

 

[leftside]

Here you go. Can't tell which factory these were made though.
https://www.head-fi.org/threads/the...39-4654-4699-kt63-kt61-6v6-etc.959519/page-12