I agree with the responses by the others. But given that you want to try to reduce the brightness by changing cables, my suggestion is that before investing in quality audiophile-oriented cables you first try the cheapest and lowest quality non-audiophile cable you can find, the kind that looks like this.
The reason I say that is that the capacitance of that kind of cable is likely to be far higher than the capacitance of an audiophile-oriented cable, which in conjunction with the relatively high output impedance of your preamp will soften the upper treble at least slightly. (The CA-7A's output impedance is shown here as being either 600 or 800 ohms; I can't quite tell which, looking at the blurry pdf scan).
See this tabulation of the capacitance per unit length of various cable types, indicating 94 pf/ft for that generic cable, which is several times as great as the capacitance of typical audiophile-oriented cables.
The magnitude of that effect will increase in proportion to the cable length that you use. Obviously, though, longer length might increase other cable effects that would be adverse.
In any event, giving that a try certainly won't cost much!
Regards,
-- Al
The reason I say that is that the capacitance of that kind of cable is likely to be far higher than the capacitance of an audiophile-oriented cable, which in conjunction with the relatively high output impedance of your preamp will soften the upper treble at least slightly. (The CA-7A's output impedance is shown here as being either 600 or 800 ohms; I can't quite tell which, looking at the blurry pdf scan).
See this tabulation of the capacitance per unit length of various cable types, indicating 94 pf/ft for that generic cable, which is several times as great as the capacitance of typical audiophile-oriented cables.
The magnitude of that effect will increase in proportion to the cable length that you use. Obviously, though, longer length might increase other cable effects that would be adverse.
In any event, giving that a try certainly won't cost much!
Regards,
-- Al