Here at the link is an old Soundstage review of the Kimber Silver Streak by Todd Warnke. Keep reading and it goes off into a tangent in a couple places singing the praises of the MAS Black and the MAS PowerMaster AC power cord from that period.
http://www.soundstage.com/todd01.htm
Here is part of Todd's comments...
"the MAS Black, in my system, offers even truer sound. In fact, when I first tried a pair it taught me a very good lesson. On first listen I dismissed them simply because they had no obvious sound! Fortunately, I have learned since then, and the MAS helped in that education of finding a truly neutral cable.."
The Black was also sold as a speaker cable. It was popular with owners of electrostatic speakers.
The Gray cables he still has (those $60 ones on the website) are not as neutral, but in a good way for some equipment. The mids and highs are a litte more forward and enhanced from neutral. I believe that internally they are the same wire as the Wadia digital cable I mentioned above.