ECC82 or 12AU7 which was first? - Page 1
Forum section: electronics / projects

author: Brasto
author_rank: Contributor
timestamp: December 19, 2018, 09:44:29 am
content: In the 1950's the new NOVAL type tube sockets appeared on the market as well in Europe as in the USA. Being an old Dutchman I have reasons to belief that Philips developed the technology to successfully manufacture the Noval tube sockets. On the otherhand I have noted that USA companies also produced this type of tubes.Question: There are hundreds of pin-to-pin compatible equivalents of European and USA tubes, the only visible difference being the tube marking e.g ECC82 or 12AU7. Which company is the original inventor, designer, of this double triode? Is he holding patents and are all the worldwide others licensed to coproduce? Did Philips/Mullard produce their tubes/valves in Europe and labelled them e.g 12AU7 to export to the USA?

author: 001
author_rank: Super Contributor
timestamp: December 19, 2018, 12:03:11 pm
content: nobody caresit is only for connector standartisationgoogle morehttps://en.wikipedia.org/wiki/Category:Protectionism_in_the_United_States

author: duak
author_rank: Super Contributor
timestamp: December 19, 2018, 07:08:00 pm
content: I think it was RCA from the US that introduced the package. However, it's a US-centric view as per:https://en.wikipedia.org/wiki/Tube_socketLook under Miniature Tubeshttps://forums.stevehoffman.tv/threads/everything-you-wanted-to-know-about-tube-sockets.287947/My hat is off to Philips for innovation, the compact tape cassette for one. Philips seemed to have a large presence in Canada whereas UK or German companies did not. I remember encountering a Philips TV in the mid 70's and seeing components, particulary the capacitors, that were in unusual packages. Compared to domestic stuff that had paper and wax exteriors, Philips was plastic which made it seem more modern.Cheers,

author: gbaddeley
author_rank: Regular Contributor
timestamp: December 20, 2018, 02:45:44 am
content: RCA released the first 7 pin "button base" tubes in 1939, consisting of four 1.4V filament types, later followed in 1941 by the first three 6.3V indirectly heated types, the 9001 9002 9003. Then 6C4, 6J6, 6AK5 in 1942, and in 1945 by the very common AM radio types 6BA6, 6BE6, 6AT6, 6AQ5, 6X4.Britain, Germany and Holland did not produce RCA's "button base" types until 1947, mainly due to the war time conditions in Europe 1939-1945.RCA released the first 9 pin "button base" tubes in 1948, the 12AU7 & 12AX7.(Ref. "70 years of radio tubes and valves", John W Stokes, 2nd ed, p135-140

author: Brasto
author_rank: Contributor
timestamp: December 20, 2018, 09:54:00 am
content: Quote from: gbaddeley on December 20, 2018, 02:45:44 amHi Glenn, 12AU7 released as early as 1948 must be the winner over Philips ECC82 which shows up in 1951.I still wonder how the tube development took place, was it Philips engineers taking a noval base and said.....let's put a double triode in here. So they did and started to measure tube performance....Guess what specs showed to be identical to the existing 12AU7 so they took the conversion tables and marked their "new" tube ECC82? Or did they talk to RCA, bought their design and became a licensed manufacturer? I know for sure Philips had great R&D labs at that time and if they had not the required knowhow they just bought the competitor e.g. UK Mullard......

author: 001
author_rank: Super Contributor
timestamp: December 20, 2018, 11:18:10 am
content: Quote from: Brasto on December 20, 2018, 09:54:00 amCommies grab same tube technology without any license. See clones at ebay

author: Circlotron
author_rank: Super Contributor
timestamp: December 20, 2018, 12:09:01 pm
content: I can't believe that they both have their own instagram hashtag.Lots of pictures!https://www.instagram.com/explore/tags/12au7/https://www.instagram.com/explore/tags/12au7a/https://www.instagram.com/explore/tags/ecc82/

author: gbaddeley
author_rank: Regular Contributor
timestamp: December 21, 2018, 09:18:56 am
content: I would guess the ECC8x series were built to same specs as the 12A T/U/X 7 series, as they are interchangeable. The internals would have been a bit different.