Large Couplers
Large Couplers were made from 2" x 1" x 3/4" solid blocks of 7075 aircraft alloy aluminum. 7075 is the premium grade of aircraft alloy aluminum, endowed with extreme hardness and strength (actually greater than some steels), and was chosen as well for its excellent thermal transmission and self-damping characteristics. Each Large Coupler was cut from a solid bar of 7075 aluminum, then hand finished. There were two standard varieties: Large Couplers, and Supercouplers.
Most Symposium Platforms (except Point Pods and Svelte Speaker Sets) were supplied with Large Couplers; these products are now supplied with improved Precision Couplers.