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As with any passive network, cables contain both resistive and reactive components. This creates resonances and anti-resonances in the cable. A series resonance is when the reactive components cancel each other. At the resonant frequency the complex impedance will be quite low. This series resonance doesn’t impede the signal flow in a cable. An anti-resonance, however, is formed when the reactive components add together to form a highly complex impedance. This “parallel resonance” does impede signal flow in the cable.

It’s generally assumed that the electrical bandwidth of an audio system should be ten times greater than the audio bandwidth. That is, the electronic components should operate out to at least 200kHz. So, what are the first issues that cause distortion when a cable doesn’t work well within that band of frequencies? Cables suffer from a parasitic series resonance at frequencies below about 1.5kHz and from parallel resonances at higher frequencies, determined by the values of the inductance and capacitance. The cable doesn’t function as an ideal inductor. All audio products act as low-pass filters. Cables without networked terminations function as a lossy low-pass filter because of this parasitic capacitance as well as shunt capacitance. The vector seen at the input terminals of an audio signal-carrying cable should be an inductive vector at all frequencies and at all power levels.

We can correct for the parasitic and shunt capacitance by adding reactive components in the network that will offset these effects.

A conventional [non-networked] cable will also operate in a “bi-stable” state. State analysis shows that a system can work in three states—stable, astable, and bi-stable. A cable carrying a low signal level will function in a bi-stable state because of the parasitic capacitance within and between the individual conductors, which when twisted or coiled together form the inductor of the cable. The low-level signal must overcome this parasitic capacitance before it can pass current (the audio signal). So the cable shifts between a capacitive element and an inductive element many times per second because of the audio signal’s varying amplitude. The cable must carry sufficient current to overcome the parasitic capacitance. That makes the cable bi-stable.

During the time it takes for the cable to shift from being astable to stable, the low-level signal carried by the cable is turned into noise. We call this “analog jitter.” Removing analog jitter is one of the reasons why MIT cables have such a black background and have such good low-level detail. The result is proper timbre, transparency, soundstage size, and point-point location of images. No jitter equals no noise component.

Think of a cable carrying two tones of the same frequency, but one is very high in level and the other very low in level. With MIT cable the low-level signals remain intact and are not converted into noise, and are sent in-phase with the high-level signal. Also, the harmonics of the low-level tone are transported in time within the complex tone’s envelope.

All of this describes the technologies I’ve developed over the years: “2C3D,” “JFA” and “JFA-2” (“Jiiter-Free Analog”), and “SIT” (“Stable Image Technology”). SIT means that the image of the instrument or voice won’t move within the soundstage.

The circuit elements in our networks are “time invariant.” That means the relationship between the input and output signals doesn’t change over time. The system should not respond differently to the same input signal at different times.

We have a whole range of impedance analyzers that we’ve bought over the years. We can increase or decrease the applied voltage and measure the impedance with varying power levels at any frequency. This allows us to fully characterize any capacitive or inductive component we use in any given cable. MIT is the only cable manufacturer that quantifies the performance of the products.