ChorAlloy™

The growing line-up of ChorAlloy-plated connectors/plugs is already being fitted to Chord Company cables.

The upgraded ChorAlloy™ plating is available on VEE3 and PTFE RCA/phono connectors, ChordOhmic speaker connectors (spade and 4mm banana), BNC connectors, most USB connectors and the connecting pins of DIN and XLR connectors.

C-series cables, Clearway USB cable, streaming cables and mini-jack connectors will remain the same.

ChorAlloy-fitted products can be identified by stickers or indicators on retail packs. Other distinguishing features are the anti-tarnish, steel-like appearance of the connectors and the enhanced performance!

 

 

---

Cable connectors and why we should care about them..

It goes without saying that any connection is only as good as its weakest link. There is little point in having an expensive ‘lossless’ length of cable if you cannot get the signal into it, transferred and out the other end.
On the whole, cables are passive devices and anything that is added is always unwanted; this, coupled with losses to the signal during transmission, result in changes to signals being transmitted.

For many years Chord Company has been getting many of its connectors custom-built. Initially gold was considered the best plating material when used with copper conductors. As the company’s understanding grew and with the introduction of silver-plated cables, later silver-plated RCA, BNC and XLR connectors arrived.
In recent years, Chord Company introduced silver-plated 4 mm speaker plugs and spade connectors. Some enthusiasts expecting gold were surprised, as gold is generally perceived to be the best plating material. Of course, there is a huge choice of plating materials: rhodium; copper; brass; nickel and copper beryllium have all been tried, with wildly differing prices and claimed performance levels.

Plating materials

It’s worth noting that gold is the third most conductive metal available. It is outperformed by silver (+148 % better) and copper (+ 140% better).
Although pure copper is a good conductor, it is susceptible to oxidisation and drastic drops in conductivity, often combated by plating. Common plating materials include tin (25 % as good as gold), Nickel (33 % as good as gold) and Rhodium (50 % as good as gold).
Better conductivity means lower resistance and, therefore, less signal loss. Less signal loss means increased performance.

Tarnishing

Even though silver is the best metal for conduction, it reacts with reduced sulphur in the air. It is a common mistake to think that silver oxidises and is, therefore, a poor conductor: this only occurs at 170 C. Silver-plating not only makes sense from an electrical point of view, it gives an audibly superior result compared to copper plating.

Silver tarnishes when in contact with reduced sulphur and sometimes the assumption is that it will drastically affect performance. Tarnishing (silver sulphide) is very soft and easily displaced when making connections, but it does cause concern cosmetically.

Although tarnish (silver sulphide Ag2s) isn’t as good a conductor as pure silver metal, it takes a long time to appear and is easily removed. Chord Company’s silver-plated contacts are even passivated to significantly slow this process further.

Tarnish takes approximately six months to develop on an untreated silver surface. The speed depends upon the amount of reduced sulphur gasses present, along with humidity and temperature. If using contacts outside, it is possible that the tarnish may also include silver chloride and silver sulphate.

In urban areas, the majority of sulphur compounds that will react with silver are H2S (hydrogen sulphide), SO2 (sulphur dioxide and carbon disulphide (CS2). In non-urban areas, the most common compound tends to be OCS (carbonyl sulphide). Silver sulphide doesn’t grow as a film, but tends to form clumps. As they grow, the clumps become thicker and slowly spread out.

Although some contact cleaning can be achieved by unplugging and plugging connectors, surfaces remain rough at a microscopic level.

ChorAlloy™ Next-generation technology

Conductivity is typically measured using DC. Chord Company has always been interested in how its cables perform at higher frequencies: as you move up through the ranges, the bandwidth of the cables increase, along with many other important mechanical characteristics.

At higher frequencies, the clear performance advantage of silver becomes less clear. The presence of the Ag2S can give rise to intermodulation effects at high frequencies. These effects, especially as they are associated outside the normal audible sine wave bandwidth, haven’t ever been considered by any audio connector manufacturers to date (that Chord Company is aware of).

Chord Company looked at different plating techniques over a prolonged period, to try to reduce this effect. Following very considerable listening results, ChorAlloy was born. This multi-metal plating system provides significant musical improvement over previous silver plating techniques and marks a major step forward in connector performance.

The technology offers much lower intermodulation than silver plating, is tarnish-free, RoHS compliant and solderable. But, most importantly, it is musically superior to previous silver-plated connectors.

---