We looked at modifying our own solder type plug and whilst this is the best we’ve used for soldered speaker connections, it proved hard to adapt for screwing.
The screw plug we produce has gold-plated copper beryllium contacts and the section where the speaker cable connects is reinforced with a machined, plated brass section. Two screws push the cable into the gold-plated copper beryllium contact.
This is a common design, often referred to as a Z plug. As a screw type connector we think it works very well. The key to the performance is the use of copper beryllium. If you come across what looks like the same plug but at a far cheaper cost, approach with a degree of caution. We have come across samples that use copper in place of Copper beryllium. Copper beryllium is not cheap and it’s used because of its high mechanical strength. The versions made from plain copper have no spring to them, and it’s the spring inherent in copper beryllium that provides the crucial high pressure connection need for the plug to perform properly.
Chord Company screw type plugs are sold in sets of four and come with colour coded caps and full instructions.