Tube amplifier for dynamic headphones – preamplifier and power amplifier at the same time


Up to now the RKV (tube amplifier for dynamic headphones), developped and admitted to our distribution in 1982, is by far the most successful tube amplifier in our product range.


Traditional Tube technology has been abandoned and replaced by completely unorthodox approaches to create a concept which is still unique in the amplifier fabrication. Also it has not been resigned latest semi-conductor technology and so a product occurred which reflects 40 years of electronics. The German patent office has secured this idea 1984 with the number DE 3200 51.


“Why headphone amplifiers” – so the Reader might ask. “Doesn’t my output at the receiver suffice?” The answer is simply No. Good, dynamic headphones have a high impedance. For high dynamic jumps, e.g. from CD-Players, they require much higher voltage levels than the supply voltage of transistor amplifiers, which would otherwise be a possibility. The same applies to Hi-Fi systems. So it was one requirement for the amplifier to bring high levels. Moreover it was important to achieve short-circuit strenght and excellent technical data, under the special note of tube sound. The existing concept possesses all this qualities.


By reason of the conformation to high terminating impedances the OTL principle has been appropriated. This concept is geared now to the classic example of the so-called transformerless power amplifier. With the help of semi-conductor technology it has proved to be a felicitous symbiosis of the last 40 years electro-physics.


Also all negative existing aspects of the tubes, like weathering and tolerance hum, had to be eliminated. The RKV-electronic manages this problems effortless. An Op-Amp in the signal path creates a servo circle that compensates all above mentioned negative characteristics of the tubes.


It is even able to stabilize the operating point automatically, regardless the weathering of the tube, so that even older tubes continue working without problems. This automatic control circuit has no influence on the quality of the sound, even at the abrasion of the parts.


 When judging the sound especially the high dynamic of the amplifier and the typical tube sound are to mention.The bass is tight and enormous, the middles are aery and from a liveley transparency and the high range shows an excellent release combined with transparent space.


 Other products on the market, which want to force their headphones to diabolic peaks by the use of smaller battery voltages or 40mWatt output power, just fail here. Cost-intensive headphones, for example by GRADO or AKG, require effort and just there the RKV is the only reasonable driver source.

 Of course the amplifer comes with all this qualities as well in his function as a pre-amplifer for power amplifiers. In this case the output voltage of the RKV is decreased to his 15th part and laid on another pair of Cinch Sockets on the backside of the amplifier.


 But there is even a third way of using the RKV. The performance of nearly 2*3 Watt is also adequate for driving loudspeakers. Therefore we use the so-called “Impedancer”, that reduces the output impedance of the RKV to the size of the loudspeakers impdedance. Basically high-class transmitters which scale down the output voltage. With loudspeakers starting from 93 dB you can receive an excellent musical result.


The RKV as an universal genius in this three category groups of Hi-Fi technology has no competitor that is nearly able to hold a candle to him in this prize class. For all the people who only consider two of this mentioned possibilities for their own use the RKV is already the only right decision.

AudioValve RKV MKII Headphone Amplifier

    • OTL - transformer outless tube amplifier

    • double mono construction

    • Alps volume control ( or remote control as option )

    • output: 2 pcs. 6,3 mm stereo / XLR combi jack and 4 pin Sennheiser jack for headphones

    • input: 2 pairs of cinch and 1 pair XLR inputs

    • tubes: actual 4 x 6F5P (ECL85) earlier time: (PCL 85 or 18GV8  )

    • power output: each channel 8 watt on 220 ohms load per channel

    • bandwide: 15 - 100 000 hz

    • damping 3600 !

    • distortion 0,002 % at 1 Watt-200 Ohm load

    • max. output voltage 100V for box 50_enl.jpg

    • sens. 0dBm

    • IC - OPA134 - full autom. - controlled bias

    • class - a

    • power consumption min. 60 watt

    • size 360*200*120 mm (d.w.h.)

    • weight 6kg

    • patent full automatic servo tube biasing ( 1982 H.Becker )

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