One thing for sure is they are one sexy tube.
Model Number:KT66-Z
Shuguang's 50 Years Anniversary
"High Polymer Compound Carbon" technology
"Super Alloy" technology
Shuguang, the premier Chinese vacuum tube manufacturer with 50 years of history in designing, manufacturing and distributing high fidelity audio tubes, has just released their '50-Year-Anniversary Treasure Series' of vacuum tubes. Grant Fidelity (http://www.grantfidelity.com) as Shuguang's distributor, is the first and so far the only one to bring these "Treasure Series" tubes outside of China.
According to Shuguang, the "Treasure Series" has adopted quite a few new technologies in the design - such as "High Polymer Compound Carbon (HPCC)" coating inside the glass enclosure to reduce the tube's internally generated noises and stabilize electron current. In addition, "Super Alloy" has been for the first time used on audio vacuum tubes construction to improve electron emission - before such type of material has only been used in aerospace industry and military application.
Shuguang Treasure Series vacuum tubes production includes over 100 processes, which are nearly 60 more processes than those for manufacturing the Shuguang clear glass generic series. All parts go through 30+ screening and matching procedures to insure quality, accuracy and consistency. Production is done only by technicians with 30+ years of experience. The newly released Shuguang Treasure Series of vacuum tubes include the following model at the time being: 300B-Z, KT88-Z, KT66-Z, 6CA7-Z (interchangeable with EL34) and CV181-Z (interchangeable with 6SN7GT, 6N8P).
