hey are being made again! The good old Telefunken tubes! Ok, not with the Telefunken branding and not made at in the old Telefunken factory. But the machinery which is used to produce them has been made during the golden era of the Telefunken company. More about the person who produces these tubes later on.
The old tubes produced by Telefunken Gesellschaft für drahtlose Telegraphie m.b.H have a legendary reputation and are highly sought after, especially in Asia. Telefunken was founded by a fusion of Siemens & Halske and AEG. After WWII the facility in Ulm continued thr production of transmitting and receiving tubes and later cathode ray tubes. Tube production reached it’s zenith in the 1960s and vacuum tubes started getting replaced by transistors. The Ulm factory was sold to the french company Thomson in 1979 and was shut down two years later.

The story would have ended here if there wouldn't be a former Telefunken employee who is still producing vacuum tubes up to this day. This is Dr. Klaus Schaffernicht, who founded the company ELROG 1986 in Lüneburg and moved to the city Lübtheen in Mecklenburg-Vorpommern. Schaffernicht probably is the last manufacturer of audio tubes in Germany. As described in a previous article, the production of vacuum tubes is not a trivial matter. Unfortunately the know how needed for that is mostly lost. Tube enthusiasts suffered from this when they retubed their beloved equipment with cheaply produced tubes from far east. Therefor the audio scene is lucky to have a company like ELROG which does not the necessary know how only but the production equipment also. Now tubes can be produced again with the quality and performance of the old Telefunken types. When Schaffernicht decided to make audio tubes it was clear to him that he would not just build mere copies of the old General Electric or RCA types. 

Elrog tubes not only look differently, their construction differs as well. Some smart ideas have been applied. The most obvious difference is the way how the electrodes are mounted. They are not placed in the upper part of the tube on a long glass stem as in a light bulb. The electrode system is mounted close to the socket which gives shorter signal paths and a mechanically more stable construction for reduced microphonics. As in the old tubes, thoriated tungsten filaments are used, the “trademark” of transmitting tubes like the 211 and 845. These operate at temperatures around 2000º Celsius and have a bright yellow-white glow. Similar to the historic tubes, Elrog uses graphite plates which are milled from a solid block. They exhibit an improved plate dissipation rating of 80W. This also allows higher output powers up to 25W in single ended amplifiers. The dark area in the middle of the tubes is a graphite coating. Through this it is possible to make an electric contact to the getter. The getter is a metallic compound, usually some barium alloys, which absorbs gas molecules. Dr. Schaffernicht didn't want the getter to be electrically floating as in other tubes. The getter is connected to the plate through springs at the sides of the electrode system. These also provide mechanical stability.

The 211 is a directly heated transmitting triode. It's advantage is a very good linearity. The thoriated tungsten filaments need a much higher operating temperature than oxide coated filaments. The 211 requires very high plate voltages exceeding 1000V. The filament needs 10V at 3.25A which is not an easy task to provide since it needs to be very clean for best sound. Ideally the filaments are heated from a DC source. AC is possible but results in residual hum due to the high filament voltage. The tube also needs a capable driver with low output impedance which can provide 150V peak to peak. Otherwise the sound would be dominated by the non sufficient driver tube and not by the output tube. All in all not recommended for beginners in DIY. 

Two years ago some early samples haves been made. These were prototypes for debugging purposes, never meant to be sold to end customers. Some of these prototypes leaked onto the market and are still offered occasionally. They are easily identified by their slimmer glass. Their glass tubes had about the same diameter as the base. In the meantime several changes have been applied and the types ELROG ER211 and ER845 have reached maturity for series production. For me it is interesting that this manufacturer is not widely known in Germany yet, while the tubes are used more and more by asians. What does this tell us? 

Besides the standard version, the tubes can now also be ordered with a silver wired connection inside the base. For now only the ER211 is available with this feature. The Elrog tubes can be sourced through Thomas Mayer. He is reachable by email:  thomas@vinylsavor.de.

Here you can also get further information about the tubes. The price is 1200 Euros for a matched pair ER211 and 1300 for a of pair ER845. Nothing for cheapskates. Or are they? Elrog products are known for the long life time. And aficionados would be glad to find a pair NOS 845 at this price.

For me it is always most interesting to get to know the person behind a product. But unfortunately Elrog resides pretty much at the other end of Germany. Therefor the following interview was done by phone. I hope to have a personal meeting during the High End fair in Munich. 

Interview with Dr. Klaus Schaffernicht

Jürgen Saile: How did the company ELROG start?
Dr. Klaus Schaffernicht: I worked at Telefunken for 18 years. 1980 I quit my employment and got an offer to manage a factory for night vision devices. But I always wanted to run my own business and founded ELROG a few years later in 1986 in Lüneburg. The Bavarians didn't want to have a company that made such strange things like tubes which led me to settle in the North of Germany.

JS: What did you produce back then?
Dr. KS: At the beginning I wanted to continue making my specialities for printing machinery. But then the laser arrived and tubes were not needed any more. So I teamed up with the company Hameg and started making cathode ray tubes for oscilloscopes. Later I broadened the portfolio with tubes for the Tornado military jet and for military helicopters. Here we did redesigns to increase lifetime. Unfortunately this made the products too good with a lifetime of 25.000 hours so no replacement parts were needed any more. We had 20% market share with oscilloscope CRTs. But then the price started to go down with increasing production from far east. So we were forced to stop production at a certain time when the business was not profitable any more.

JS: How did you come to audio tubes?
Dr. KS: The production of a vacuum tube is always quite similar. When you look at a Chinese or Czech 211 these are copies of what RCA did. RCA developed this type for the US army. It was used in telecommunication devices. We use a different kind of construction. I wanted to get rid of the light bulb stuff. This unexpectedly improved the sound quality. But there is more. We put the getter on a defined voltage potential. It is connected to the plate. This way the tube operates in a more stable way. This is not a new invention but was common practice in CRTs.

JS: Would it be valid to say that ELROG tubes match the quality of the old Telefunken?
Dr. KS: In terms of sound quality, we are the best, no doubt about that. During the first two years we had several problems, but all of them got solved.

JS: How long does it take to manufacture a 211?
Dr. KS: We are a small company. That's why we can only produce a limited number of tubes per day.

JS: Are there plans to make other types besides the 211 and 845?
Dr. KS: I didn't want to mention that since we are quite early in the development phase. But we are working on a 300B. 300Bs are nowadays made by many suppliers. We want to make sure we deliver the best possible 300B. First prototypes are done and we are running comparisons with the historic 300B. Our goal is to make at least an equally performing tube as the Western Electric tube.

JS: Do you have data for the lifetime of your tubes? Are you running long term tests?
Dr. KS: Yes of course. We have sample tubes running continuously. We currently passed the 3000hr mark. Our goal is to reach 5000hrs. But we have not verified that yet since the tests still need to continue.

JS: Dr. Schaffernicht, thank you very much for the interview.

When looking for “quality made in Germany”, Elrog tubes perfectly match that. Built like a tank. The tubes are produced according to standards as used for the military. No Chinese Nostalgia toys. These tubes sell through their exceptional sound quality. Everybody who tried Elrog tubes in his amplifier, kept them.

It first appeared in German in HiFiStatement.net magazine, 10.01.2014 (see HERE)