It is well known from the electro-magnetic theory that in an ideal electric conductor with infinite conductivity, the electric current propagates to the surface of the conductor, as the electromagnetic field within the conductor is essentially zero due to infinite conductivity. Since any real-world electric conductor is not ideal and has finite conductivity, a part of electromagnetic (EM) field, surrounding the conductor, propagates into the conductor through its surface, exponentially decaying as it does so, and turning its energy into heat. This part of the EM field penetrating the conductor (herein called “loss field”) induces an electric current within the interior of the conductor (herein called “loss current”). The density of this “loss current” inside the conductor is proportional to the strength of the “loss field”, being maximal near the conductor surface and decaying toward the interior of the conductor. This phenomenon is often called a “skin effect”. The depth at which the current is attenuated by a factor of 1/e in the interior of the conductor is commonly called “skin depth”. The skin depth is inversely proportional to the square root of the frequency, thus, as the frequency increases, the current aspires closer to the surface of the conductor. The propagation speed of the “loss field” and skin depth also depend on the frequency of the EM wave and electromagnetic properties of the conductor, which is a direct outcome of Maxwell’s equations. The higher the frequency of the signal is, the less the skin depth and wave propagation speed are. It is also obvious from the theory that the propagation speed of the electromagnetic (EM) wave inside a conductor is much slower than in a good dielectric or vacuum.
Suppose we apply a sinusoidal voltage signal to the conductor for a substantial time, so that both external EM field surrounding the conductor and the “loss field” inside the conductor achieve “steady state”. In this case there is no signal shape distortion at the load end of the conductor. That is why there is no measurable harmonic distortions in the conductors. Now suppose the applied signal is abruptly cancelled. The external EM field in a surrounding dielectric also cancels very quickly, as its propagation speed is high. The “loss field” inside the conductor decays for some time after signal cancellation due to its much slower propagation speed, so does the “loss current” induced by the “loss field”, therefore representing some “energy storage” or conductor “memory”. Moreover, the EM wave of the “loss field” and “loss current” experience phase shift inside the conductor. It can be easily shown that the phase of the wave of the “loss field” at the “skin depth” is changed by 1 radian – a far from negligible figure. Thus, a small portion of applied signal (external EM wave) and induced electric current are “memorized” and delayed inside the conductor. This “memory” produces a signal shape and phase distortion in electric wires. Despite this distortion is relatively small, especially at low frequencies, it may be significant for higher frequencies and for multi-frequency or complex signals, such as musical signal.
Known techniques attempt to reduce skin effect in the electric wires in order to maintain signal integrity with minimal electrical losses and distortions. The existing art includes specially geometric shaped conductors with increased surface area, including cables with arrayed solid and tinsel wire conductors (litz), multi-layer conductors with different conductivity of layers (which stimulates the current flow through the layers with higher conductivity), use of paramagnetic materials in the conductors for the similar purpose, applying a voltage to the surrounding dielectric in an attempt to rearrange the field distribution in the dielectric and the current in the conductor, etc.
These methods only attempt to control or reduce the skin effect itself, but due to complex dependency of the “loss current” upon the signal frequency, conductor geometry, line characteristic impedance, signal source and load impedances, it is very difficult to effectively manage the skin effect uniformly across a wide frequency range. As a result, all existing conventional audio cables have audible distortions and sound coloration. Regardless of the purity of conductor material, its shape, dielectric constants, propagation speed, cable capacity, inductance, resistance, conductor winding, etc, the “loss current” is still there, so is the conductor “memory”, and so are the distortions caused by them. The only way to cancel these distortions is to eliminate the “loss current”.
The core of the LCDC® method is to provide means of maximum compensation of the “loss current”. We use proprietary passive compensation circuits that extract the “loss current” from the conductor and apply it back with sign inversion. Thus, at the load end of the cable we get pure signal with “loss current” distortions eliminated.
For audio cables, this breakthrough technology provides fantastic signal purity, deep, clear and natural sound unachievable with conventional cables. Video cables with LCDC circuits provide clearer crisper picture with natural deep colors unseen before.