Virtually all of the RCA Connectors used by today's top cable manufacturers are made from brass. There are a number of different brass alloys, generally featuring a combination of copper (around 60%) and varying amounts of zinc, lead, and even tin. The presence of these other metals greatly reduces the manufacturing cost by making the material much easier to machine and process.
From an electrical standpoint, these other metals are considered impurities that drastically reduce the electrical conductivity of the resulting alloy. For example, the conductivity of brass alloys is only about 26% that of pure copper. As electric and sound engineers, we have always believed that this loss of conductivity (almost 75%) of a connector, directly affects the overall performance of a terminated audio cable.
While most cable manufacturers ignore this situation and focus on marketing, DH Labs engineers have been working with top metallurgists to develop and refine the ultimate connector alloy. Years of research have led to the introduction of our exclusive "High Copper Alloy" TM. This material is made in the U.S.A. to ensure the highest quality and is composed of 99.5% pure copper, with a conductivity rating that is at the top of the industry. Trace amounts of two other (non-magnetic) metals are added to provide the adequate hardness and strength required for an RCA Plug to hold up over time. Even our plating process has been modified to maximize signal transfer. Simply stated, this is the finest performing connector anyone has ever made.