I make no guarantees. Therefore, self-heating is less than 0. Datasheet : KT Handles Plate Voltage up to V. We have more Special DataSheet than other site. SO i really like kt88s and unfortunately they cant fit in Bugera s.
|Published (Last):||19 February 2018|
|PDF File Size:||11.52 Mb|
|ePub File Size:||5.95 Mb|
|Price:||Free* [*Free Regsitration Required]|
KT90 and types and brands exist, and what you can do with the this tube. Also the most common electrical circuits are given for KT88 and For a collection of datasheets, follow the link to 4tubes. For this, click at 4tubes. The age of audio tube inventions has ended around , and for the non audio tubes, as far as I know only the Klystron and the Travallig Wave tube were invented.
I would call the frame grid an excellent idea, but no break trough kind of invention. After this, there was only refinement and miniaturization, which are not inventions. Moreover, miniaturization is always at the cost of good tube curves, because of tolerance issues becoming more dominant. Historically, there has always been competition between Europe and the USA, breaking things down to a level, such as the refusal to use a metric system in the USA, or the refusal in Europe to set industrial standards.
Of course each side invented their own tube sockets, as if there were not enough of those yet. Even today it can be very clearly observed that a popular tube socket will make a tube more accepted, and vice versa.
The most popular socket is certainly the octal socket, though technically speaking it is not the best. Add to this, the Europeans have patented the pentode. So for 25 years, the Americans had to pay a licence or find another solution. Well, and as things are with competition, they tried another solution, called the beam tetrode. A beam tetrode is a work around the pentode patent, and has no other purpose. A beam tetrode works like a pentode, but has the third grid replaced by deflection plates.
That works also, but still not as nice a real third grid. However, the beam tetrode did it's job and the best know family member of this kind is probably the 6L6. Today 6L6 is used mainly in guitar amplifiers, because of it's 'distorted' sound. After the patents ran out, the USA gave up on the beam tetrodes, and real pentodes were made there as well.
I want to put up front this situation with the pentode patent, because it is often forgotten, but still many of the tubes and developments resulted from this situation.
In Europe the EL34 was "the" big pentode which was the result of a long evaluation. It starting with the AL1, the first large output pentode, for radios.
After that AL4 was developed. Then with 6. In the USA it was the more sloppy 6L6 that won the race. Saying that KT66 and 6L6 are almost the same that leaves us with four very popular power pentodes. Any other differences are just playing with numbers and pin-connections. The end of the evaluation is the KT88 and the crown is the EL Our Own Damn Socket Type. Many really great tubes got forgotten before they had a chance to get remembered. The EL never had a breakthrough because of the socket.
This is a pity, because the EL socket is much nicer than Octal. It has a guide pin like Octal, but then 10 pins with clear positioning too. So unlike with Octal, no idiot can press in the tube in the wrong position, by using two hands. So any broken off guide pin cannot occur with EL After El there was a side step called EL which was unique because it had a frame grid and Zirconium gettering.
However, it uses a magnoval socket, another socket type people didn't want anymore. EL3n Smaller pre-type of EL Beautiful coke bottle glass, and perfect pentode inside. No NOS spotted, but good used tubes are cheap.
Collector's item. Low cost, reliable tube. Cheap and good beam tetrode, with some distortion though. Beam tetrode. KT stands for 'Kinkless Tetrode. Original idea by EI - Yugoslavia. This is modified EL which works like a KT This never became very popular, though perhaps it deserved better.
It really works! This can be called the American equivalent to the British KT, but audiophiles have distrust against anything industrial and military, just because they believe industrial products sound not musical, and because military sound aggressive. Yet this tube is much sought after still for guitar amplifiers, which abuse the tubes as a matter of principle. Ratings of are roughly the same as the 6L6GC while the A has higher ratings at some points.
The has a plate voltage rating of V watts 5 watts more than the 6L6GC and a screen rating of V watts. KT66 KT stands for Kinless Tetrode however was marketed from the beginning as an audio tube, with a whole series of excellent schematics included in the original data sheet.
This was a clever piece of marketing. This is the same tube, but here in a black glass version. Black glass is electrically better, because it guides electrostatic charge away from the inside of the glass.
When you really like the physics of tubes, this is the preferred version. When you like to see something glowing inside, this is not the preferred version. The is another industrial grade 6L6. It has Zirconium coated plates, making the plates act as a getter.
The screen grid was carbon coated, giving it some overload of capacity The total is 3 Watt! The control grid is gold plated, giving it lower leakage. Cathode is stand-by proof. Low leakage socket. How do we know all of this? From the above paper :. Designed by the General Electric Co. Use of these parameters shall be entirely at the user's own risk.
And no, it is not as easy as you would like, because a bad getter indicates a defective tube. A tube with lots of use on it, but still working, naturally shows no 'defective' getter. That is why getterology is of little use for most people. This becomes particularly clear, when tubes with obviously defective getters are praised on Ebay as excellent working, and both seller and buyer do not notice the bad getter, indicating the end is near. Strangely, there is no interest for this, though it is clear to see by the getter often, the tubes are rubbish.
More difficult is also the reverse situation: The getter looks fine also to me and when you test such tubes, they are rubbish. Here, the biggest mistake of all is made: Many think, a fine looking getter is the same as a fine working tube. This is simply not so. So in short: A good getter means not the tubes are good. A bad getter means the tubes are bad, also when the optical situation look so nice for the rest of it.
It's amazing how bad a KT88 getter can be and still the tube works. On the left picture you see a tube that was for sale an auction website. It is clearly visible that this getter has gray edges. Also some part of the getter is gone. This tube probably tests fine, but what the buyer doesn't know is, most of the lifetime is gone. On this picture you see two working, used tubes that were offered on Ebay, for very high prices.
The left tube getter looks fine. The right tube has some of the getter edges gone as well, and the GEC stamp is badly burned. These are the brown type of getters, at the end of lifetime these start to develop concentric rings, of some blue-gray color and after more use, the edges begin to disappear. As a next step, the tube gets gassy, without the getter being white. At this moment of Ebay sales, they probably test still good.
I was send this picture by someone who found those on Ebay, and who was afraid they were fakes. Well, yes they are fakes. Inside is the Chinese KT88 system clearly visible. What is even worse about these, they were offered as NOS, and they are in the box with a bad vacuum getter. You can see the gray ring around the getter. With all getters, the edges are thinner than the middle part.
So once you see the edges are no metallic looking anymore, this means some part of the getter has been used up.
KT90 and types and brands exist, and what you can do with the this tube. Also the most common electrical circuits are given for KT88 and For a collection of datasheets, follow the link to 4tubes. For this, click at 4tubes. The age of audio tube inventions has ended around , and for the non audio tubes, as far as I know only the Klystron and the Travallig Wave tube were invented. I would call the frame grid an excellent idea, but no break trough kind of invention.
KT88-98 Datasheet PDF
The KT88 fits a standard eight-pin octal socket and has similar pinout and applications as the 6L6 and EL Specifically designed for audio amplification, the KT88 has similar ratings to the American which was designed for use as a servo amplifier. It is one of the largest tubes in its class and can handle significantly higher plate voltages than similar tubes, up to volts. A KT88 push-pull pair in class AB1 fixed bias is capable of watts of output with 2. The transmitting tubes TT21 and TT22 have almost identical transfer characteristics to KT88 but a different pinout, and by virtue of their anode being connected to the top cap have a higher plate voltage rating 1. The screen grid is sometimes tied to the anode so that it becomes effectively a triode with a lower maximum power output. It was manufactured in the U.
KT88 Tetrode. Datasheet pdf. Equivalent
The KT88 is one of the few classic audio output valves. The last valves M-OV produced after a run of 28 years - were branded Gold Lion and here this Russian tube made by Genalec carries the same branding, but this valve has been made for the modern audio market. The basic figures given are for single ended use, but the valve is almost invariably used in push pull pairs or these days in parallel push-pull. The envelope proudly proclaims that Genalex are a Russian company. A far cry from the import of Eastern European valves decades ago when they were just marked Foreign.
KT88 Genalex Datasheet