I have 1m AC-9's on my mono extremes. I mainly purchased them to have shorter power cables.
The sound change was minimal if even perceivable. One thing I can state is that the sound certainly didn't worsen in any way. 
The AC-9 is a thick cable and you need to take some caution with it's limited flexibility. They are surprisingly flexible for a cable that is nearly 1" in diameter, but they still need room. If you do get them, make sure the cable has no tight turns and can lay nicely. I had some trouble with mine because the amps each sit directly in front of an outlet. This proved to not work well. The end connectors had a lot of pressure on them and the cables didn't want to stay tight on either end. I've since added another outlet between the amps and the cables lay perfectly now.
hello ...

I bring you the fruit of my little tests, including power cables sector ...
Last year I bought a cable industry to a gentleman in belgique, which work well on the electronic and made good cables ...

he gave me the cable, if I was satisfied how, I buy him.
is the cable on the 1st page photo attached.
I used it on my cd player, and the result is simply remarkable, and incomprehenssible for me !!!!!!!!!!!!!!!!

but it works as hell !!!!!!!!!!!!!!
alas I sold all my equipment with hi fi ...

As I go again, and I bought a complete system I began to make similar cables
these days, waiting for Mr Klaus sent me my amps, I prepare cables, and a barrette sector ...

on the cd, it works great!!
for blocks, I can not say for now ...

I warmly receives them !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
cable used a Yarbo GY 7000 PW Furutech plugs are, but the little secret of success for
it "works well" is the length of the cable ...
2M50 ...

it feels great cable, but given the result obtained, it is not a problem ...

for 100 euros, the gain is important, and it only matters to me ... and especially my ears !!!!!!!!!!!!!!!!! I do not want to tell stories, but just to give you a nice result, with this cable
here the link ...
http://www.homecinema-fr.com/forum/viewtopic.php?f=1059&t=29791483&p=174789229#p174789229