Can you elaborate? You seem to be saying that linear cables are the key,
No, I am simply saying that compensating for a system's resultant tonality flaws is not best served by applying tonally colored (non-linear cables) to achieve a perceived synergy.
but couldn't the same linear/non-linear argument be applied to other components?
Absolutely. But with cables it is more evident, especially when many of the same type are in the system. An additive or subtractive signature becomes more and more evident as each one is inserted into the system. And this is easy to confirm by trying such an IC cable in the line-stage's tape loop.
And how do you know which cables truly are linear (beside Joe Kubala saying that his are)?
I am not going by what Joe told me, I am reporting what I heard in my own system as each of my cables was replaced one-by-one by a K-S cable. The listening session lasted nearly 5 hours. And after Joe left my home, still with his cables here, I was able to play for another week with these, and mine and several Purist cables that had arrived that week. Listening tests with the other cables later that week confirmed what I had observed when Joe was here - the cables I had been using did indeed have some serious colorations.
Which manufacturers don't make this claim?
Good point, and that is why I pay little or no attention to claims, and instead I audition such products in my own system.
Are all the linear ones as expensive as K-S and Stealth?
I never intended to imply the Stealth cables' sonic attributes here. I have not done the same kinds of tests with their ICs and Speaker cables yet. But from the few Stealth cables I have heard here, and have since purchased, they have become the benchmark for all other cables to compare. I do hope to hear these vs. the Jade cables soon. Initial impressions with these is that they are mighty good.
As for finding that tonally neutral cable that is not so expensive, this might not be so difficult. The problem here is that it is difficult if not impossible to retain all the rest of the strengths that come with the higher-priced cables. Again, frequency-response is only a fraction of the attributes to be evaluated here. The capabilities of the Io/Callisto/JL-3 electronics makes it immediately evident when a cable destroys the dynamics and dimensionality of the music. And the Stealth cables have made me very aware of the magic still lurking in these electronics. A good front end and revealing speakers helps. 8-)