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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.

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Thursday, February 23, 2017

News from the ELROG Tube Factory 4

Hi!

While production of the 300B, 211 and 845 tubes is in full swing, the next ELROG tube type is in development.




The first prototypes are being made. The tube will be launched at the High End fair in Munich this May. Here another teaser photo:





More abut this new ELROG tube in upcoming posts.

In a previous post I showed some photos and video clips of the assembly of the filaments of a ER300B. Today I will show the next steps in the process of vacuum tube making.




Here we see the electrode system of a 300B with filaments and grid. Only the plate is still missing. Each assembly goes through careful inspection and alignment.




Proper alignment of the grid ensures that the finished tube will meet the specifications and pass final tests.



Here we see Olena carefully inspecting and adjusting this vital part of an ELROG 300B:




Next the glass base is prepared...




... and the electrode system is welded to the metal rods in the glass base:




Now the system gets washed in a special solution before the plates are mounted.





Here we see Matthias inspecting one piece of the plate which is made of two halves.








Adding the plates to the system...




... welding the plates to the support rods which run at either side of the tube:





This is the result from this step:




Now the two halves are welded together so that there is no gap remaining between them:




The only part missing before the internal construction is complete is the getter. The getter is stored in a little ring:




This ring is mounted at the top of the system. Here it holds the getter material which gets flashed and creates the silver mirror surface later in the production process.




Now the internal structure is ready to be sealed within the glass envelope.




This step will be shown in an upcoming post. Stay tuned!

Best regards

Thomas


Tuesday, February 21, 2017

The Ultimate Line Preamplifier, Part 6

Hi!

Another ultimate line preamplifier is in the making.




It shares the same circuit and all silver transformers and plate chokes as the previous ones. The pre-wired top plate:




All silver transformers and chokes are on a separate sub assembly:




Which is mounted below the top plate:




The only parts missing are the silver AVC volume controls which will be mounted to the front plate and wired to the rest at the final assembly stage.




This one shares the same color combination as the ultimate phono stage.




Both will be on demo at the High End fair in May. Visit us in rooms F231c and F231e to listen to this preamplifier combo.

Best regards

Thomas

Tuesday, February 14, 2017

Integrated SE Amplifier with the 46

Hi!

Here is another single ended amp based on the 46. This time an integrated with input selector and volume control.




It is basically the same circuit as the recently shown 46 power amp.




A DACT stepped attenuator serves as volume control directly after the input selector which in this case only selects between two inputs. One RCA and one XLR. The latter goes through a pair of input transformers before it is routed to the input sect switch.





The parts on the top needed some rearrangement to make room for the input selector and volume control.



Since this the power transformer does not really need a large cover as on the previous amp this helped to free up enough space.




When tested with the volume control at maximum and with a line stage this amp sounds just like the last one. The 46 is absolute musical ecstasy.



Extremely rich tone colours almost to the point of exaggeration. Bass is surprisingly solid and well defined with the right speakers.




Not as much resolution as a thoriated tungsten output tube. But sheer fun to listen to.




This will certainly not be the last 46 amp built be me. Stay tuned!

Best regards


Thomas





Thursday, February 9, 2017

The Ultimate 300B Amplifier - Part 1

Hi!

After the excellent results from the fully differential 300B amp an ultimate version with all silver transformers and plate chokes was the logical next step.




It shares the same circuit and chassis design of the previous one. All relevant transformers and chokes are upgraded to silver.




These are all the silver goodies which go into one channel. Like the copper version the amp will have 4 chassis. Two mono blocks and each with it's separate power supply.




The sub assembly with all signal relevant transformers and chokes, except the input transformer which is directly mounted to the top plate near the input stage:





These mono amps are meant to complement the ultimate phono and line stage for a fully differential system without caps in the signal path. A set of these power amps together with the phono and line will be demoed at the High End fair in Munich this year.

Stay tuned for updates as the amps get completed.

Best regards

Thomas

Wednesday, January 25, 2017

News from the ELROG tube factory 3

Hi!

Time to give some update about whats going on with the ELROG tubes! We had been tremendously busy in the recent months. Many things to take care of. We are working hard to keep up with the demand.





We had been overwhelmed with the interest in the newly announced ER242C. More requests had been received than we plan to make in the first production run. Sorry to all those whom I had to turn down. We will make sure to set up a second production run later this year. The first run will be next month with deliveries expected in March.




We'd like to thank all customers who put their trust in the newly founded Deutsche Elektronenröhren Manufaktur GmbH. We are happy about the tremendously positive feedback received for the tubes delivered from the new company. We are also very proud about the extremely low failure rate. So far there had been zero returns of 300B tubes produced under the new company. There had been very few 211 and 845 fails which were caused by mechanical defects during shipping and which of course got replaced on warranty. So far the total failure rate is a tremendously low 1-2%. Of course 0% would be ideal. But to be realistic, any technical product can fail and the type of failures we saw were caused by shipping and had been immediately apparent upon receipt. We will work hard to keep the quality up.




We are very happy to announce a new distributor for ELROG tubes. Amtrans joined the family and will distribute our tubes exclusively in Japan. LiveAcoustics, our distributor for Singapore will also cover Malaysia and plans to set up a shop there as well. Emmanuel Lebreton, who covers China, Hong Kong and Taiwan has been quite active to promote the tubes in his area and is in the process of setting up his website Baoling Audio. And of course George Lenz of TubesUSA.com continues to distribute the tubes in USA and Canada. All other regions and the European Union are covered by us directly.  Send an email or call if you want to order tubes or if you are interested to become distributor for your country. The elrog.com website will also be set up soon and regularly updated with distributor and order information.






Above a picture to show you some of the faces behind the tubes. George Lenz (left). Matthias Klepper (right) and myself. The photo was taken at the ETF where we also donated a pair of ELROG ER300B for the auction. Anders who auctioned the tubes sent this photo of his amp with the Elrogs installed:






I am getting many questions about new tube developments. Besides the ER242C another new type is in the pipe and we plan to launch it at the High End fair in Munich.






Yes, Deutsche Elektronenröhren Manufaktur GmbH will be exhibiting at the High End fair in Munich. Visit us in room F231e to see and hear the ELROG tubes. In addition ELROG tubes will also play in room F231c in a joint set up with PrimaryControl, Wolf von Langa and VinylSavor.

Looking forward to meet in Munich!

Best regards

Thomas