They are vacuum tubes designed and built for audio use. KR produces a variety of 300B tubes that are actually significant enhancements of the original designs. Some are made with pretty glass, others have structural and sonic tweaks of the original design. Particularly for the various 300B series, one must be careful in choosing the exact tube for the application. The 1610 and T-100 are the brain children of the late tube wizard Dr Riccardo Kron, founder of KR Audio in Czech Republic. Sadly, he did not live long enough to see all of his dreams to fruition. Luckily, his wife (also Dr. Kron) has taken over the business and continued the tradition with an incredible passion.

The 1610 is the king of the current day audio tubes in terms of its massive size and its power abilities. All large body and selected small body KR Tubes are built with Pyrex glass and are completely hand assembled and tested in very small batches. The KR Audio lead engineer, Mr. Marek Gencev does engineering control to ensure consistency. This means that each KR tube is precisely matched to specifications. These tubes have an lifespan of 10000 hours.

Class A and Single Ended/Push Pull describe the architecture of the amplifier. Class A amplifiers are the least efficient  because the electronics are always working their little hearts out.  Class A amps produce the least distorted most true sounds available. Single ended amplifiers use tubes to drive the transformer.  Most electronics produce sound in a single ended mode (on the RCA output jack).  This is a perfect input for a single ended amplifier.  All KR Audio Amplifiers are Single Ended.

Push-Pull amplifiers work like a slinky. The transformer is energized by two tubes operating exactly out of phase. To minimize componentry, push-pull amplifiers frequently use balanced inputs from the equipment. This is less common  Courtesy of the extreme care in workmanship, all KR amps have a power bandwidth that extends from 20Hz to over 20000Hz. KR tubes are used in all sorts of audio applications.  To see a push pull audio amplifier that uses KR tubes, go to www.renaissanceaudio.com.

These questions are enough to make the hair stand up on the back of any audiophile's neck! It is a debate that continues on with a theological zeal. Technically, there are only two ways to amplify signals. Voltage swing can be increased or Current swing can be increased. There is a mechanical analogy. When you run water through the kitchen sink and shut it off quickly, the pipes bang with the inertia of the water passing through them. The force of the water is dramatically changed through this process. This is much like current flowing through a wire. Voltage swing is like having the same water in the pipe, but having a balloon at one end and a piston at the other. Very little movement of the water will make large size changes in the balloon. Tubes work like the piston and the balloon. Transistors work like the kitchen sink. In truth, each has their strengths and weaknesses. We opted for tubes in the output stages because, in general, there are significantly fewer components required to make a tube amplifier work well. As such, the possibility of the sound being altered by a component is reduced.

Negative feeback is a method of circulating a small piece of the output signal back through the circuitry to gain better control of the natural hysteresis of the output transformer. Negative feedback can also be used to flatten the frequency response of a given circuit.

 The reality is that it can slow the response of the amplifier and dull the sound of the finished product.

  We are proud to print that no KR Audio Amplifiers require feedback of any kind to alter the signal.