Choosing cables for Passive applications?

I am wondering if anyone has some good experience with passive amp/pre combinations and what cables have worked well.
Personally I am using a Cardas Nuetral Ref.(RCA term) between my CD and Amp (amp has attenuators on back for volume). I have read that the lower capacitance cables work well as they alter the signal less, but many manuf. do not specify the ratings.
Also I noticed that the Nordost cables have MUCH lower capacitance than the Cardas. Would this make them a lot better in my application than the Cardas, at least theoretically?
It's difficult to swap cables around a lot so I'm looking for some pros on the GON!
I run 2 sets (one 1/2m, one 1m) of Luminous Audio Sychestra Reference ic's between cdp > Reference Line and between Reference Line > amp.

Before this I was running 2 sets of Reference Line's own DSL cabling which was very good and made specifically for my application. The Luminous Audio blew them away. You will see them occasionally on AG.

good luck
Capacitance is not the only issue that "alters the signal" ... personally, with a passive pre I would be more interested in cables that had low resistance and low impedance.
I think a better cable (in your system) is a better cable rather than a cable having lower capacitance etc. being better. Maybe I just don't understand or care much about the technical aspects of cables and what makes one cable better than the other. I can tell you that the Nordost cables have such a different sonic signature as the Cardas that you're comparing something that is quite different.

With passive, the biggest thing you have to worry about is the quality of the passive pre and the length of the cables (especially the length of the cable connecting your amps to the preamp). Maybe capacitance, low resistance, and low impedance all play a role, but I would still say trust your ears.
Yes, the Nordost cables do have much lower capitance. Knowing this, I have used both Nordost Blue Heaven and Red Dawn with superb results on my Reference Line Preeminence 1, Series 2. While I never had Cardas for comparison, I can say that the Nordost TOTALLY blew away some comparably-priced Audioquest. The Nordost are so amazing I can't imagine using anything else now.
Another thing is that plagues passives is improper system matching. This, and or long cable lengths can result in the lost of dynamics and a muddied/softened representation. Besides Nordost, there are many cables that will work well in a passive system, it's just that cables that tend to be sharper in focus tend to help compensate for the deficiencies. When done right, passive certainly sounds very good.
My system uses a passive preamp and the runs are as short as possible (30 inch & 1m) Ridge Street Audio MSE's.
Short lengths and low cap is desired on passives. On my second system, I have the Placette passive line stage connected to a Fourier OTL. I use the Pure Note Cerulean cables that maintain good bass response and speed. Nordost (Valhalla) IME is way to thin and bright.
Thanks for the responses, I haven't been able to get to them for a while so I'm just beginning to experiment. I had recently used an Ayre V5-x preamp in the system and it sounded very good, but when I plugged the CD directly into the amp (using the 6' Cardas) the sound opened up and had even more detail. I am currently awaiting a Monolithic Sound passive/active linestage and I hope it will do as good a job as direct (wishfull thinking) or at least as good as the Ayre. Also for a bit of fun I'm going to try some cables from Canare (Star Quad 4) to begin experimenting.
Wow the Monolithic is a GREAT piece of gear! My wife and I put a tonne of hours on this since we've got it. The beauty of it is we can run passive OR active depending on the position of the volume knob.
It's really quite simple. CD requires NO preamplification circuit at all, whereas the phono, can use a little gain from the preamp, but only when listening at very loud volumes!!! The real amazing thing is that there is little to no difference when going from passive to active.
Is there a catch? YUP no remote!
Anyway, now I can begin my cable experiments.