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I n 1952, when Dr. Riccardo Kron was still a young student, he was a passionate audiophile. At that time, in Europe, only the British amplifiers, like Leak and Quad were available. The sound reproduction from those amplifiers was fantastic, but those applications were push-pull circuits where matching the output tube was almost impossible due to the imperfect vacuum.
KR TubeMaking.jpg - 37092 Bytes As he became more expert in hi-fi, Dr. Riccardo Kron  realized that the best results were obtained by using  circuits in Pure Class 'A' with mono triodes, but he also knew that power was extremely limited and the amplifier lacked sufficint dynamics.
Although tubes such as the 45, 2A3, and the 300B gave exceptional clarity and sweetness, they had severe power limitations.
With such limitation, very efficient loudspeakers with a sensitivity of at least 92dB and above were required. Such speakers were typically very large for domestic use. Hi-fi and the problems of reproducing sound with vacuum tubes remained the same till 1994 when Dr. Kron met a staff of experts in the newly former Czech Republic that had gained their technical experience in the research division of the Tesla High Vacuum Technology facility in Prague.

Acquiring the necessary machinery and space to work, Dr. Kron and his team began to resolve some of the problems inherent in audio tubes.The 211 and the 845 tubes were eliminated as models because their construction was base on an obsolete technology requiring a high working voltage of over 1200 volts. Consequently, the old and glorious example of the Western Electric 300B was adapted. The challenge was to re-create something similiar to the 300B without requiring substantial modifications regarding the output power. The analogy would be to re-manufacture the old Model T Ford engines in a 1998 factory for a 1998 automobil. It is one thing to re-manufacture an antique for sentimental reasons, copying a tube already built, relaunching a famous, historic brand-name with great commercial success, designed sixty years ago. But it is another to develop a new product incorporating all the sweetness and clarity so much admired by tube affectionatos with a completely new philosophy never tried before.
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KR TubeMaking1b.jpg - 36087 Bytes At this point, with all due respect to the legendary Western Electric and its 300B, Dr. Kron and his team   decided to built something better and more modern that complimented other technologies that were developed during the last few years and in the application of the WE300B to single-ended amplifiers.
What KR Audio Electronics was trying to do was to make more perfect the compatibility between analogue and digital by building each tube by hand to achieve a vacuum of 10 - 9 Torr. KR "painstakingly hand-crafted" tubes are quality controlled using a laser to see if the alignment actually conforms to a perfect geometry. In all of their tests, the laser has proven them correct. Heating a ribbon filament having a 32 surface emission; a special coating creates unrivaled dynamics which up until today has not been surpassed (Patented).

The patent on the ribbon filament permitting the use of 32 cathodes is effectively accomplished by having four surface emissions. Therefore, the tube has greater dynamics (eight filaments x four surfaces = 32) and, consequently, greater output power. Using grids with a special project design that allow the tubes to work both in voltage and current.. Developing plates with high dissipation and fed with a relatively low voltage. Making sure the internal resistence is less than 600 Ohm.
The KR 300B is electrically identical to the WE300B (Western Electric), but with an output power of over 18 Watts in Pure Class A.
The KR300BXLS is also electrically identical to the WE300B, but with an output power of over 25 Watts in Pure Class A.
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KR TubeMaking4b.jpg - 38257 Bytes Both these KR300B can be substituted for any other   300B advantageously permitting enormous gains in   output power. KR Audio Electronics also manufacture the   following High Vacuum High Power Audiophile Tubes
The KR32B is a medium power triode capable of providing an output of 30 watts RMS in Pure Class A.
The KR53B is a medium power triode capable of providing an output of 35 watts RMS in Pure Class A.
The KR52BX is a medium power triode capable of providing an output of 45 watts RMS in Pure Class A.
Naturally, as an Audiophile and lover of good music, you cannot ignore either the input or driver tubes designed to drive this kind of output power.

That's why, KR Audio Electronics developed the KR1 and the KR5, super linear and non-microphonic Hi Vacuum tubes. The high vacuum and a perfect mechanical construction make all KR tubes already identical and matched in the manufacturing process.

Please click here for KR Hi - Vacuum Tube Data

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21st Century Technology on 1930's Tubes

The KR Hi Vacuum Tubes are the first new directly heated triodes to be manufactured in over three decades. Hand built in the Czech Republic with their patented 32 cathode and ribbon filament structure, the KR tubes will provide more power, lower distortion and better tonal fidelity than is currently available with any other triode tubes.

KR Audio Electronics feature a full range of Power Triode tubes with rating from 15 to 30 watts in single-ended operation.
T-1610 (Kronzilla)





KR2A3 Single Plate


Each KR Hi Vacuum Tube come with a TWO YEARS WARRANTY.
A serial number is written inside each tube as part of its assembly.