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(Last updated: 02-Jan-2017 19:29 )

Important Copyright notice.

we do not support any copying from this website. Still we often find parts of our text here, copied on Ebay auctions, private web sites or company web sites. I am sorry we have to write this here, but if you copy something from this website without permission, it is not just we "do not like it" and kindly ask people to remove it. We used to do so in the past, but we were often treated as the bad guys, instead of those copying our work. So this we don't so any more. We have now have an agreement with a specialized intellectual property law office in Muenich Germany, and this works a lot better. All we do is, send the internet URL to them, and they do the rest. We take no influence on how they work, as they are fully authorized. Best advice I can give anyone, in such a case, remove any text that was copied, and cooperate with our lawyer, like sign the declaration they send, and make an agreement for their charges. We at jacmusic are not involved in that, also not financially. We only get involved, if no agreement could be made. So again, sorry for writing this here, but ever since we do, it works a lot better.

A discussion about opinions

If you were looking for that, I have to disappoint you. I avoid useless discussions like monkey plague. It is better to recognize there is a lot of emotion behind tubes, as well as a lot of rationality from the engineering point of view. Things get a little difficult when an rational hardliner wants to make emotional users look silly for not understanding the physics behind it. Wheras for other people a discussion becomes closed, when some tubes sound better than others, even though they do not know how electronics work. Though myself I try to understand some part of both worlds, I am somewhere in the middle. So, what's a valid argument for one person, is invalid for another. So yes, we all know JJ makes low cost copies of all popular tubes, and some prefer those for that reason. Whereas others avoid them, simply for the same reason. Myself, I had several bad experiences with JJ tubes, and that triggered a factor inside myself, saying JJ is only good to save money. I have an RFT ECC82 tube at a particular position in the amplifier of my Hammond organ, and only with that tube, the percussion of the organ sounds so fresh the way it does. So if that tube breaks down, I want another RFT ECC82. Though this tube costs only 20 Euro or so, I would pay a lot more I had to, just to get that sound. I have similar feedback from a person with a guitar amplifier. He bought a quad of the expensive TESLA E83CC, and after finding out the amplifier sounded better as ever before, he bought another quad, so to have enough spare tubes. To make it even more complex, many people now just buy NOS tubes because they see prices go up and up, and regard it a safe and good investment.

Confusement with part numbers: ECC803S - ECC83 - E83CC

The best  triode of it's kind, is by no doubt Telefunken ECC803S.   I have no numbers available, but I know first hand from an ex TFK employee living in Ulm, only very few of those were ever made. So you can stop searching for those sleeping lots in old warehouses : That never existed. He told me, the initial buyer was an equipment company Wandel & Golterman in Germany. For them this tube was constructed, for their test equipment. I know this company, I have visited them several times, for other reasons in 1990. Sure I can say, they were small by then, and they must have been even smaller in 1960 when ECC803S was made specially for them only. Realistically speaking, today most of that equipment is destroyed now. So finding ECC803S has very low chances.

Later, Telefunken sold the ECC803S on the market. Any HiFi purpose was not intended, and the tube was too expensive from the beginning. So things stayed as they are, very few were made, and it is the remains of those few that we are all looking for. So a large demand, and no supply. That explains the price. Technologically, the tube is superb. TFK ECC803S has lowest noise, lowest microphonics, at high gain, and a balanced and matched tube out of the box. It is matched so well that two random tubes, you put them together and you have a matched pair. And all of that is guaranteed for 10.000 hours. And they means with that not maximum 10.000 hours, but minimum.

So the say TFK ECC803S, it is the ideal tube. Well.... it is indeed, but prices are crazy. I have seen them for 1200 Euro already, while I write this in 2011, and this doesn't seem the limit.

Some basically very good web sites, describe the search for the -Holy Grail- Telefunken ECC803S as pure nonsense, and advise you to try out new made JJ equivalents because they are so cheap and also good. Well I did so, and I was disappointed as could be. First thing that wonders me, is the JJ ECC803S data sheet. There is only basic information in there, even less as with an ECC83. For me, that is no ECC803S, as all the typical things that make this tube, is not specified in the JJ data sheet. Then, when testing them, the JJ tubes showed largest differences between the two triodes, and started to drift on my tube tester already after several hours. So yes, I stay with my opinion, the old quality of the Telefunken tubes was never reached by any factory. Not even in the days of full tube production it wasn't .

As far as the sky high prices are concerned, personally I can understand it when you have a 3000 Dollar phono amplifier, a 4000 dollar Yamamoto amplifier, and 15.000 Dollar Avantgarde speakers, you plug in all kind of ECC83, an only with that one Telefunken ECC803S, or genuine TESLA E83CC the noise is reduced further as no other tube will offer you. Then it is up to you if that is worth 150 dollar for a NOS Tesla, 350 dollar for a used TFK ECC803S, or even 1000 Dollar for a NOS TFK. With NOS TFK I recommend you to buy only such that DC parametric tested.


SECRET process of PATENTED process?

The results of secret processes are inside the bottle, such as: What cathode material to use, how to prepare the base chemicals for that, how to store them, how to mix them before use, how to apply it, and ..... where to buy it. A good cathode is one of the most difficult things, if you keep in mind that preparing basically "good" cathode materials at all is a major problem today. Have you ever heard of new made factory balanced ECC83 with a guarantee that this lasts for minimum 10.000 hours? Of course not! They have no idea how to do that.

The sky high price is because NOS is hardly found. So this inspires the few remaining tube factories to reproduce them in some sort of a way. While doing so, here comes the problem: There is NO WAY to come even near the historical specifications. Processes have always been secret. Reason is, you can either patent is, or keep it a secret. Like the aroma mixture of Coco Channel No5, or Coca Cola is not patented, but a secret. Patenting protects against copying but not really. It also means you need to publish the recipe, everybody can look up a patent. Besides a patent gets invalid after 25 years. So what's the use of patenting? Often it makes copying even easier. So they rather keep it secret than patenting it.

Patent the recipe, the patent is valid 25 years, and after that the patent is a free recipe
for others to copy it. Do you want that? TFK said no!


How would you like to prepare those ultra special multi layer cathodes. All old men who knew the tricks have died. Machines and production instructions are scrapped 50 years ago. Manufacturers of chemicals are gone, and if not they do not even know what you talk about when you ask for it. Then the special cathode sleeves, of a material purity and precision that we can say definitely for sure: No company on earth produces this any more. Try to order gold plated grid wire of so any so many microns, and this and that ductility, and 99,995% purity, produced under vacuum, and whatever. If you ask today, they have a good laugh at you. Well I guess all in the end, something "near" could be build, but as we know even that was too much trouble. So the days were real ECC803S was produced are gone, and that is permanent. I do expect the re-boxing re-stamping fakers to make NOS tubes from used tubes, but that is another story. (read about it here)

So here we are, and marketeers in today's tube factories see those ECC803S sell on Ebay for 1000 Euro one. It is obvious they seek a part of the profit. Only thing is, they take a plain ECC83, gold plate the pins, stamp it ECC803S, but you have a fake still. What is the difficulty with JJ and Russian Tung-Sol unreal ECC803S?


To be as qualified as the Telefunken ECC803S, here at jacmusic.com we think a  new made ECC803S
must at least show these things:

  1. It is a FRAME GRID tube. Study this item carefully if you are interested. These are masterpieces of mechanical design. A link is here:
  2. It has less than 15%  plate current difference, clearly written in the data sheet.   So they are "balanced" per definition.
  3. 10k hours minimum lifetime,  during which time the data sheet. is compliant. Clearly written so in the data sheet. of course. 
  4. All important parameters have minimum and maximum values. For instance grid leakage.
  5. Low microphonics specified in such a way, you can VERIFY it.
  6. Can be used in stand by as long as yo want, and no cathode detoriation will take place.
  7. Shock proof, also in such a way that you can VERIFY it. That means acceleration is specified in "g", and the noise result which this produces. So if a company writes "low noise" tube on it, that is better than nothing, but for an ECC803S they should say: How low, and how tested it, and what is the minimum acceptance level. That is ECC803S. All other tubes are ECC83 in an ECC803S jacket.

Let me explain here what a frame grid is, and what's we think at jacmusic.com what is so nice about it. Perhaps you have opened up an old radio tube, and removed the grids one by one. When you touched them with your thick fingers they were damaged. Specially the very fine ones. Well not so with a frame grid! With a normal (none-frame) grid, the grid wires are used to keep the grid bars in position, right? This may seem kind of natural, but there are other ways to do it. A non-frame grid needs a minimum diameter (=strength) of the grid wires. If they get too thin, the grid would get too sloppy. However for miniature high gain tubes, you need thinner than thin wires, and for high transconductance you need them closest to the cathode. Here is where frame grids come in. So they make first a FRAME from hard metal, mostly Molybdenum. The frame stays inside the mica. Around this frame the grid wires are wound. This method allows extremely thin grid wires. You will think: "So what?" Well.. for HIFI something very very nice comes in, and THIS is why people like frame grid tubes so much. Frame grid tubes have a very interesting kind of microphonics. Look at a guitar... the thin strings give the higher tones. And of course more tension makes the tone higher... and shorter strings have higher tones too. Now in a subminiature frame grid tube, like TFK or TESLA, all these things come together. The wires are so thin, and tension is so high, and they are so short, that they have a resonance frequency above 20.000 Hz. This makes when you knock on the Audio frame grid tubes like TFK ECC803S, you hear not "dingggggggg" as only any regular ECC83, but you hear only a dumb noise like "zmb" and that's it. The tube will never environmental noises, no matter of the gain is 100x. Once you experienced the difference, you will ask with any tube: "Is it a frame grid tube". Well unfortunately the answer is "No" with most of the tubes. And now you understand why I say, some manufacturers feed this hype with non-frame grid tubes.

6922 Frame Grid (Spanngitter)

So, to reduce the confusion,  here is a nice overview of what is available.    Always keep apart the CONSTRUCTION and the BRAND and the part number, as these are different things, and you CAN get confused easily. .

We are only interested  in the construction here,  not so much under which brand it was available, and not what great part numbers they stamp today on regular standard tubes.  The brand is only on the outside,  but the thing to find out, what we have on the inside!

6922 Frame Grid (Spanngitter)

FRAME GRID extracted from a 6922 tube

First there is the Philips Long plate.  I always use to say, the child called "success" is claimed by many fathers.  You see this tube on position  5 and  7, in the picture below.  Because it's so successful, it is found in the family of Valvo, and SEL, and Siemens, and many more.  Telefunken had a similar baby,  but from their own production.    These are on position 1 and 2. It's a good tube, but no frame grid.

The Telefunken ECC803S is a special tube.   It is a FRAME GRID tube,  in German called "Spanngitter". we think at jacmusic this is where the "S" comes from. The FRAME GRID allows extremely thin grid wire, and extremely small distance between grid and cathode.  Besides the grid dimensions are very precise.  Ideal to make a high gain miniature audio tube.  Only making frame grids is not everybody's business, and so far I have seen this technology only at TFK and TESLA.

You can recognize the frame grid tubes by the typical shape of the plates, and of course by the frame grid.  The plates of frame grid tubes reach go extremely close to the grid, and this is done by the "pit" you see stamped in the middle of the plates. So the plates are kind of boxed always, and there is a put in the middle. Look at position 3,  this is the TESLA frame grid version. So it has those short, cubicle shaped plates. You think you see a  large plate distance, which is not true.  The real plate distance from parts of the plates in the middle which actually come every close to the grid.    

Frame grid tubes are more precise, and more expensive.  Normal grid can be made with thinnest wire of  100u.  Would you use thinner wire, you get unstable constructions.   For manufacturing a frame grid tube,  first a frame is made, and around the frame a 10u wire can be wound. Note, that this is thinner than the human eye can see. First time you open up an old frame grid tube, you only see a gray opaque layer. These are the wires actually which are too thin to see, but they do fragment light rays in all directions.

This ECC83 picture was placed here with kind permission of my friend and customer Mr. KRIEGEL.

  1. TFK ECC83. Smooth plate. No frame grid tube.
  2. TFK ECC83. Ribbed plate. No frame grid tube.
  3. TESLA E83CC   (Frame Grid tube, boxed plate)
  4. TESLA ECC803S, 32 code = PRAGUE. Long Plate, no frame grid tube
  5. VALVO E83CC RED SERIES. Ribbed plate. No frame grid tube.
  6. TFK ECC803S. (Frame Grid tube, boxed plate)
  7. VALVO E83CC. Ribbed plate. No frame grid tube.
  8. Mullard M8137. Wide square plate. No frame grid tube.

Comparing ECC83 Tube brands and reading data sheets

Telefunken ECC803 Data sheet

Click here to see it

What you should do is look at the following:

1) Text description

Read at the first page about Reliability, Long Life, Tight tolerances, Vibration and Shock (both!), and the special cathode. So they do not just say "Vibration proof, but they say you can apply 2.5g acceleration at 50Hz vibration a the tube works normally. Also with reliability they do not say say "high", but they guarantee a failure rate of 1.5 per 1000, per 1000 hours. This is INCREDIBLE GOOD. It means after 10x 1000 hours, still 985 tubes are within specifications. (See next part). Those that are not within specifications are not necessarily dead, but just is outside one of the very tight limits for ECC803S, and may still test "good" on any tube tester.

2) Minimum and maximum values

This is the second leg, ECC803 Stands on. So not just "typical" as with normal ECC83. Look what it says under the number "250" (plate voltage). You should use a 1.6k cathode resistor and then will measure typical 1.25mA, and deviation is maximum 0.15mA. Mind you this is an auto bias specification, easier to meet than a fixed bias specification. Still, they dare say what is a test setup, and what are the limits. I tried to get this from Electro Harmonix, it was impossible.


Here is something which will make you realize better what I mean. Compare the Telefunken ECC803S Data sheet, with the (new made) Tung-Sol ECC803S Data sheet

The JJ ECC803 Data sheet (New Production)

As you can see here JJ Data sheet is looks more like am ECC83 Data sheet than like the Telefunken ECC803S.

Conclusion: Literally everything what "makes" the TELEFUNKEN ECC803S what it is, it is completely missing to the full 100%.


JJ made full reproductions of several TESLA tubes at the beginning of their production. They used a licence for the TESLA brand name, and only later on they changed to JJ branding. So we can say from the beginning period, they had all the stamps, and boxes etc. This makes it difficult to keep apart GENUINE TESLA tubes from the JJ made ones. However it is clear, that collector's value of the GENUINE TESLA is going up very much the moment, whereas the early period JJ made, (TESLA branded!) tubes, have a low value, and I see them not considered interesting by collectors of NOS tubes, since this is not TESLA NOS at all. So you do need to keep this apart carefully, but it is difficult.


The main characteristic of the GENUINE TESLA is the different shape of the glass dome at the top. JJ made TESLA have a more round dome. The GENUINE TESLA have often a darker kind of getter flash, though sometimes the shiny flash was used also. If you see the darker flash though, you can say right away: GENUINE TESLA. Once you learn to see the differences, it will be the first thing you look at. Also when the seller has the original old, dusty, bulk packs of the E83CC TESLA, it is another sign of trust. Also read this article about faked tubes on this website.

So they also copied this confusing part numbering system, without any need.  With JJ,  their ECC803S is a  normal  long plate tube, with an "S" of which letter I can not find the meaning. Also has NOT  the points as mentioned  at the beginning of this page, which qualifies TELEFUNKEN ECC803S.

Some more information here


The Tung-Sol ECC803 Data sheet (New Production)

If you can find it, let me know! Tubes that I have tested, were plain ECC83.


Valvo E83CC Data sheet

This is beautifully tube, with full compliance to the original TELEFUNKEN ECC803S Data sheet


Differences I see, is the VALVO E83CC specifies the data even more complete than Telefunken, when looking at the capacitances. When looking inside the tubes, it is clear this is no frame grid tube, but to compensate, they made it a triple mica tube.

Valvo E83CC with Triple Mica

Conclusion: A secret tip! Totally underestimated tube, full 100% compliant with the TELEFUNKEN DATASHEET.


Now  TESLA did something strange and a bit silly,  and everybody is still today confused about it.     They REVERSED the part numbers for frame grid and normal grid tubes.    It is crazy. So they even put the "S" on a normal long plate tube.

There is the LONG PLATE TESLA VERSION, which is NO frame grid, but called ECC803S.  
There is the FRAME GRID TESLA VERSION,  but  called E83CC.
Don't try to understand the logic of this. There is none.  It is Czech humor.  Just work with it the way it is!

Frame grid tubes are more precise, and more expensive.  Normal grid can be made with thinnest wire of  100u.  Would you use thinner wire, you get unstable constructions.   With a frame grid first a frame is made, and around the frame a 10u wire can be wound. 



Everybody is (still) so confused by that. 

GENUINE TESLA ECC83. Not frame grid version.

Original TESLA ECC802S. (ECC803S looks the same)

Note the somewhat flattened part of the dome, best visible with the last tube. The getter is darker colored as with JJ.

Note the somewhat flattened part of the dome. The getter is darker colored, indicating GENUINE TESLA.

Here is a nice detail, and very interesting! In many cases, the TESLA pins are a little smaller diameter than normal, it can be 5....10%. You need a fine micrometer tool to measure that. I do not know the reason, but I have observed it many times. It is additional proof such tubes are not JJ. This diameter deviation if you want to call it such, I have also observed often with TELEFUNKEN E88C which is almost identical construction as TESLA E83CC. Now, tube bases (the lower part, the "coin" ) were normally bought from special suppliers. So most likely Telefunken and TESLA used the same vendor for this. It proves the close relations between TESLA and TELEFUNKEN.

ORIGINAL BULK PACKS for TESLA E83CC. This is the normal way they were packed.
For a very detailed article about tube faking with TESLA tubes, visit the HALL OF SHAME, faked tubes


  1. TFK ECC803S is the queen of high gain miniature triodes. Absolutely impossible to ever re-build it. Top class NOS Prices of those were 100€ in 1999, then soared to 200€ in 2004, 500€ in 2008, Now in 2011 they are 1200€. Just wait until someone pays 2000€ for one.
  2. To my opinion  TESLA  (NOT JJ)   E83CC frame grid tubes are the BEST you can buy, when you do not want to spend so much on Telefunken tubes. These are fully identical construction, and on same level with the TELEFUNKEN  ECC803S tubes that they are cloned from.  Same kind of price race here, but on lower level.
  3. JJ are low budged tubes, with all that belongs to that.


Hey--- what you see here are real ones.. :)

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