Saturday, June 25, 2016

SA Lab White Knight


Audio designers have two semiconductor devices at their disposal. These are vacuum tube and transistor. Tube is ideal for voltage amplificaition and has linearity range of tens volts. Transistor with linearity of maximum 1 Volts is meant for current operation. Tube provides required output power in union with output transformer. In the traditional solid state audio engineering context transistor does the same job by means of any kind of negative feedback.

SA Lab White Knight includes emitter repeater in the form of transistor module for current management. Voltage amplification is performed by step-up transformer of really unique design. The uncommonly complex transformer with pass band 5 Hz – 300 kHz complies to strongest requirements to it. The transformer is properly great SA Lab know-how and the heart of incredible White Knight.

White Knight’s creator Alexey Syomin supposes that traditions of solid state design with transistor as voltage amplifier and negative feedback usage are formed due to complexity and low manufacturability of aforementioned transformer.

The other most important know-how Mr. Syomin realized in White Knight is employing of different thermo stabilizing compounds within the single (!) module to provide optimal and stable temperature conditions for module’s elements. Transistors are mounted upon bottom layer of berillium oxide. Capacitors and resistors are placed in different tanks filled different compounds. It took more than 6 kg of expensive German compounds for amplifier producing. The module manufacturing is the task of baffling complexity and it requies much time. One might say the same of White Knight’s transformer.

White Knight’s bipolar power supply has separate toroidal transformers in their shoulders to prevent any “dirt” from mains supply. Four transformers are manufactured by means of highest precision facilities that guarantees highest power supply poles’ symmetry.

There are no negative feedback used in White Knight. Amplifier operates in pure class A before 20 W.

Military grade contact-sealed relay are used for input signal commutating. In Direct mode the signal’s routed bypassing volume control.

Technical specifications

Output power (8/4 Ohm), W - 90/180
Distortion 50% power - 0,03%
S/N uw - 106 dB
Dimensions, mm - 460 х 460 х 190
Weight, kg - 65