DISCLAIMER

DISCLAIMER: Vacuum tube circuits work with dangerously high voltages. Do not attempt to build circuits presented on this site if you do not have the required experience and skills to work with such voltages. I assume no responsibility whatsoever for any damage caused by the usage of my circuits.

All rights of photos and text reserved. Usage of photos or text from my blog on other websites or for any other purpose only with prior permission. If you want to use any material from my blog please contact me by email.



Monday, May 20, 2013

211 and 845 Triodes Made in Germany

Hi!

As I mentioned in my post about the High End fair in Munich this show turned into a very interesting event during the recent years. Joe Roberts is right when he says: "You never know who walks in at the fair in Munich". On one of the days at the fair, I got introduced to Dr. Schaffernicht who is one of the last (if not the very last) producers of vacuum tubes in Germany.






Dr. Schaffernicht is the owner and General Manager of the company ELROG GmbH & Co Elektronenröhren KG. As you can imagine, it was very interesting to talk to someone like this at a HiFi show. But I got really excited when I received an invitation to visit the company. Of course I didn't hesitate and accepted.




The company is in the beautiful area of Mecklenburg, about 100 km east of Hamburg. I took a flight to Hamburg and a car to get there. The area is very green with beautiful roads with trees on either side.

The ELROG facilities are in a city called Lübtheen, which is about 40km south of Schwerin, which is the closest larger city. The company is in a nice Villa in the heart of the town. ELROG used to develop and produce special purpose tubes mainly for aviation applications. For example picture tubes for head up displays or gas detector tubes. They had been very successfull in this business but demand for tubes ceased some years ago. Hence the shift to audio tubes. Dr Schaffernicht has a long history in the vacuum tube industry which spans back to the early 1960s and even late 1950s.




He started his career at Telefunken. His father was the development manager at the famous Telefunken factories in Ulm, which produced the finest tubes in the world, including such precious pieces as the EC8020. After he left Telefunken he built up and ran various businesses. Always vacuum tube related. For example developing and producing Oscilloscope tubes. With this background Dr. Schaffernicht has a vast knowledge in vacuum tube technology and has many many interesting stories to share.




This was an unique opportunity to spend two days with him and to get many insights into the tube manufacturing process and history.

The photo on the right shows the man behind the company. Dr. Klaus Schaffernicht. During my stay in Lübtheen I met him as a very nice person. I was humbled by his knowledge and willingness to share it. I am especially thankful for his hospitality and his permission to write about this visit on my blog. When ELROG decided to produce audio tubes, it was clear from the beginniung that they would not just copy GE or RCA 211s and 845s as all the others do. When Schaffernicht first looked at some old production 211 or 845 tubes he found them to be made very similar to light bulbs in the way how the electrodes are fixed within the glass and how the connections are brought to the outside. ELROG wanted to make something better and unique. Which they fully achieved, not only in the way how the tube is constructed. This becomes apparent when you see the tubes which look quite different to any other 211 or 845:






Of course they also have the thoriated tungsten filament. The plates are made of graphite like most of the old production tubes. But the plates are more massive and make a distinct solid impression. During manufacturing the tubes are evacuated through a stem at the top. After evacuation about one third of the tube surface gets flashed with a Barium getter which ensures excellent vaccum throughout the lifetime of the tube.




The dark area in the middle of the tube is a coating with graphite. Through this area an electrical connection is made between the plate and the getter. Dr. Schaffernicht hated the idea of a getter which is not at a defined potential but electrically floating as in other tubes.




The photo above shows how this contact is made. This is probably one of the reasons for the superior sound of the tubes which has been reported by users of ELROG tubes.

Assembly of the tubes is a manual and labour intensive process.



The photo above shows pre assembled triode systems. Filament and grid on the right and the plate added on the left.




As you can see, the plate is a massive structure which allows higher dissipation than the 75W which are specified for GE 211s for Class A operation. This plate can easily handle 100W.




The photo above shows the evacuation process. The tubes are mounted upside down. Evacuation takes many hours. After evacuation is complete, the tubes are sealed and the getter is flashed. This is done by a big coil and application of RF at high power. A big RF oscillator and amplifier is needed for this job. Of course it operates with tubes:




Finished tubes go through an extensive burn in process:







During the burn in the tubes are operated for 50hrs at high current. This releases remaining gases which are trapped in the graphite plates and other metals. Those gasses are captured by the getter which reacts with those gasses and binds them. This is done before the bases are mounted:





After burn a beautiful brass base is attached to the tube:




Final quality check of tubes which are finished with bases:




A comparison of a Ug/Ip curve between ELROG and General Electric, the first photo shows a NOS GE 211 / VT4C:



ELROG 211 tube:



Dr. Schaffernicht personally overlooks burn in and quality tests:






The ELROG 211 and 845 triodes have now reached a mature state and are in series production. I am pleased to announce that these tubes will become available through me shortly! Please send inquiries about ELROG tubes to thomas -at- vinylsavor -dot- de. I will make these tubes available at special introductory prices. They come with a 6 month warrantee for emission which is double the usual industry standard of 90 days and 1 year warrantee for mechanical faults. Full money back guarantee within 2 weeks from purchase in case you are not happy with the sound of the tubes!

Watch this space for updates about ELROG and new developments. This was not my last visit in Lübtheen and I am looking forward to a closer ELROG/VinylSavor cooperation. Stay tuned!

Best regards

Thomas

21 comments:

  1. Great article Thomas. Thoroughly enjoyed it.

    ReplyDelete
  2. I thought these were smaller until I saw the second to last photo. These tubes are big and beautiful. It is good to know there is someone out there who still knows this art so well.

    ReplyDelete
  3. Superb stuff, thanks for sharing.

    ReplyDelete
  4. A truly great stroke, Thomas!
    A sincere bravo! to Dr. Schaffernicht... and to you.

    ReplyDelete
  5. Hi Thomas,

    is there any plan to produce other types of tubes, i.e. 45s?

    Thanks,
    Bernd

    ReplyDelete
    Replies
    1. Hi!

      I in discussion with Elrog about the development of other tube types

      Thomas

      Delete
  6. This is a extremely interesting story, Thomas! Great news - thank you very much.

    You have to be envied to meet this man. If I ever have to build another tube amp it would be a pleasure to use some of his tubes.

    Best regards, Jo

    ReplyDelete
  7. Hi,
    very interesting. I am living about 30 miles away from Lübtheen.
    And I did not know that.
    Thanks for information!
    Best regards frome Tubeman

    ReplyDelete
  8. Can these be purchased in the USA?

    ReplyDelete
  9. Hi!

    These can be purchased from me. I ship world wide

    Thomas

    ReplyDelete
  10. Hello, are ER845 direct replacement to standard 845 tubes ?
    Like for KR845, I have read here & there things that give me doubts...
    I have also read somewhere that it was possible to try a pair for 2 weeks by paying caution, is it true ? Thanks & best regards, Bruno

    ReplyDelete
    Replies
    1. Hi!

      The Elrog Er845 are compatible to the old production 845s like RCA. If I remember correctly there was once a KR version with lower filament current. An amp designed for such a tube would not be happy with a standard 845. Yes you can get a pair from me for trial

      Best regards

      Thomas

      Delete
  11. Thanks, how much is the caution for trial please ? I am in France, Bruno

    ReplyDelete
    Replies
    1. Hi!

      The full purchase price. Email me for details

      Thomas

      Delete
  12. Hi Thomas,

    Are you making the 300B tubes ?

    Brian

    ReplyDelete
    Replies
    1. Hi Brian,

      I hope to report news on the 300B next month. Stay tuned!

      Thomas

      Delete
  13. Hello!
    Are there any plans for a 2A3?
    Cheers!

    ReplyDelete
    Replies
    1. Hi!
      in the moment the 300B is being released and in product ramp up which will take another while. When the 300B proves tobe successful other types might come as well

      Best regards

      Thomas

      Delete
    2. Hello Thomas,
      I am very interested in the Elrog 300Bs for application in my Manley Labs 300b preamplifier http://www.manley.com/neo3br.php . I've rolled at least six sets of 300Bs including WE (Old), WE (new - actually still have these and like them), EH, Tesla, and my current regular usage VAIC Valve (guessing early 96ish production) over the last 8 years or so. Multiple valve rotations for voltage, rectifier and input have also been taken. That said, I'm very much open to new tubes (especially 300Bs). Have you heard the 300Bs in a line-source application? any thoughts?

      thanks in advance!

      Delete
    3. Hi!

      Honestly if you rolled that many tubes and you are still not happy, maybe you should change the line stage ...
      I will build a line stage with the ER-300B and will report about it on my blog

      Thomas

      Delete