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Although the Silent Plug is their least expensive product, Audio Exklusiv takes its performance potential very serious. The company literature boasts of dramatic enhancements in detail, soundstage and dynamics as well as a reduction of distortion and coloration. Big claims for such a tiny device. Most audiophiles will rightly be skeptical. Vibration issues in the mechanics of unused RCA jacks? Since the Silent Plug seems to be a unique product aimed at a previously unknown problem, I contacted Andreas Schönberg at Audio Exklusiv.

Q. What led you to believe that damping at the plug level was significant enough to pursue?

A. What we found is that various mechanical aspects were influencing the sound of hifi systems by at least 50%. If you do simple tricks like using damping foils for the cabinet or just put spikes under various components, you can easily hear the changes. To understand why you must apply logic and simple physics. In the end you come to the conclusion that more or less all parts in a hifi unit influence its sound: the cabinet, screws, circuit boards, connectors and so on. This was and is the basis we started to work on. My partner Peter Wagner came up with the damping material which we currently use. We found it extremely effective at killing off almost all resonances regardless of frequency and experimented with it in every application that made sense. We finally arrived at the unused female RCA plug and found its construction inherently prone to vibrations from airborne and subsonic noise.

Q. How did you arrive at the current design and did you go through a process of R&D with different materials and shapes to settle on this final plug?

A. One parameter of the design was to avoid a structure which would require excessive space or add any resonances due to shape. Besides this production and manufacturing had to be reasonable. That’s how we finalized this plug shape. Inside there are 6 bore holes all filled with our special material. What you are seeing is only the middle pin. This is designed to damp the spring in the female socket. The other five damp the surroundings. We chose aluminium because it was sonically neutral and contributed little resonance of its own as well as being fast enough to release the vibrations/resonances of the connectors. The shrink wrap adds some damping to the aluminum but the effect in minor.

Q. How would you address the skeptics that the effects of the damping here would be inconsequential in the grander scheme and that any sonic benefit would be solely due to RFI/EMI shielding?

A. To shield the RCA jacks is not difficult. It’s relatively simple to create a good product with a gold finish and shiny logo but the shielding in the Silent Plug contributes only about 10%, perhaps 30% with digital. The rest is mechanical. To prove that we conducted demonstrations with the damping material directly in the connector, no plug. The effect is the same.

Q. Do you plan on further applications for this technology?

A. We are actually working on plugs for loudspeaker terminals as well as on XLR connectors.

With these prelims out of the way, it was time to install the Silent Plugs. Would they be unmasked as marketing hype or had Audio Exklusiv really found a legitimate new problem to solve? The Silent Plug arrived as I was reassembling the main system. To avoid complications from adding a new component, the plugs went into my computer-based system on the DA&T U-2 headphone DAC/Pre, first in head-fi use and then driving the Swans M-200 Mk III powered speakers.

The DA&T/Swans combination has broken in well and demonstrates a remarkably enticing and refined signature - revealing without being aggressive. Afterwards the plugs saw duty in the unused AUX1 input of the AudioSpace Reference 2S preamp. This fed the Bel Canto 200.4 amplifier into the Apogees with the inclusion of the Paradigm Reference subwoofer for a combination of full-range scrutiny and fun. The Silent Plugs were tried in a wide range of electronics to check if the plug’s barrel width would present any issues with chassis connector spacing but it proved universally acceptable.