Furutech anti-vibration feet, which look like ordinary rubber. But things are not as easy as they seem.
Furutech Power Filters and Splitters E-TP615, E-TP609NCF and E-TP809NCF are highly efficient and clearly enhance the sound of audio systems. At the same time, the E-TP609NCF and E-TP809NCF do not contain any filter elements (capacitors, chokes, transformers, etc.).
Because the design seems quite simple and the sockets of the original original component (IEC and Schuko) are freely available, there are many attempts to make similar but ultimately cheaper splitters. However, an improvement in sound compared to the original is not achieved. One reason for this is neglect of the effects of vibrations on the electrical signal transmission line.
urutech uses feets that resemble regular rubber in these splitters, but the material similar to black rubber contains the Furutech piezo ceramic and carbon nanoparticle additive used in many Furutech power connectors (plugs, sockets, wall sockets). The result is a significant reduction in vibration resonance. If there is no significant difference in the frequency range up to 4kHz, then there is up to 10dB resonance attenuation above 4kHz. These frequencies are in the range of human hearing.
It should be noted that after 13KHz resonance peaks are not observed even without piezo-traces. These frequencies are in the range of human hearing.
In the accompanying pictures, the red graph is the E-TP609 without piezo splitter but the blue is equipped with four.
Test Method: FFT analysis using a small microphone attached to the e-TP609 AC power distributor with four Piezo Insulating Footers placed on a vibrating base.