It is now widely understood that the quality of the power supplied to an audio system is of paramount importance. Recent developments in isolation and power conditioning technology attest to this along with developments in power cords, their terminations and the receptacles they fit into. Indeed, an amplifier can be looked at as sophisticated modulated power supply. So what comes out will be a reflection of what goes in.
Only within the last few years have we come to know the importance of the quality of the devices that connect power to our systems. These include AC in-wall receptacles, AC and IEC cable mount connectors. The quality of these devices can have a profound effect on the sound we hear, thereby guaranteeing a secure AC electrical connection should be paramount in any manufacturer’s hierarchy of priorities.
What are the most important considerations for a secure AC electrical connection?
1.) Appropriate Hardness: The contact material must maintain its exact shape over time without any adverse effect on the sound
2.) Appropriate Springiness: The material should have the ability to rebound from the compression of first contact and expand to make firm long-term contact. This is highly important as a superior contact has the ability to eliminate vibration due to the movement of electrons (current) or electromagnetic fields (signal) through the contacts, as well as to eliminate micro-arcing that occurs where there are gaps in the contact. For clean transport, secure contacts are crucial.
3.) Conductivity – While of paramount importance it is, in a sense, trumped by the importance of Appropriate Hardness and Appropriate Springiness. So a highly conductive, but soft material or a material subject to fracturing, such as copper or brass may not be the best choice. It turns out that Deoxidized Phosphor Bronze approaches the ideal set out in these first three points. Also, magnetic materials are to be avoided as they will introduce spurious interactions.
4.) Appropriate Choice of plating materials: The type of materials, their combinations and thickness must be carefully chosen. Also, not all plating methods are equal, more typical gold plating or “flashing” and “spattering” is inexpensive, non-uniform and easy to achieve in a low-tech facility. Hard plating is more difficult to achieve and must be accomplished in a higher tech facility. Typical plating methods involve Silver, Gold or Rhodium. More exotic combinations include Copper, Silver and Gold, Silver and Rhodium, Gold and Palladium. Nickel is to be avoided as it degrades the sound.
5.) Surface finish: At a microscopic level, where metal meets metal, the more flat and uniform the final finish, the greater the level of contact. Strict control of surface quality, including uniformity of plating thickness, is a must for cleaner sound quality. Highly polished flat surfaces will yield the greatest area of contact, minimizing micro-arcing and vibration anomalies.
What should the audiophile expect from higher quality connectors and receptacles?:
1.) Safety and reliability: The quality of construction should exceed all safety requirements. All fittings should be positive and grip with a force that will exclude the possibility of failure.
2.) Value: Whatever the price paid, the part should perform as claimed and meet or exceed all expectations.
3.) Performance: While a gold plated part may look beautiful, in the end, the quality of connection should transport the listener to new hidden realms of enjoyment.
The Lotus Group