How many cable companies actually manufacture their own cable?
Perhaps Mogami, Belden, Canare and a few others. I am willing to bet most cable companies do not manufacture their own cable, but simply buy cable, throw on some techflex or other custom jacketing, and do nice terminations.
I like the spirit of OP's initial query. Hopefully, the big guys are not junk-sourcing to china like so many audio electronic companies. Valid questions.
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.