Very little use. I switched to XLR early on in the system build.
These are very special indeed. The first CRL Branded FIM interconnects. Very stiff which helps with "Strain Relief". The Quote below tells the history and sums up their sound better than I could.
Cable Research Laboratory is an evolution of Winston Ma's original and highly respected First Impression Music (FIM) Cables. A most enthusiastic and passionate user of the cable himself, Chip Winston liked the products so much, he bought the company. I quote the following partly from Chip's address on the CRL website and partly from his cordial and prompt email correspondence:
"Having used the Gold and Silver Series cables for several years with some of the finest tube electronics in the world, I never found their equal for pure neutral sound transmission"
As a businessman, the company's history was also intriguing. CRL's high energy conductivity cables were originally developed in the late 1990s by First Impression Music, Inc. and their cables became recognized internationally for their 'tube-like' sound. In 2002, FIM's business and cable designs were purchased by Musical Surroundings, Inc. which then became Cable Research Lab, Inc.