Preamp-power amp interconnectors advice

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

@Jafox (and others): That might be (and probably is) a flawed electronics somewhere in my system; however, I don’t think that the CA-7A, a flagship preamp from Nakamichi is intrinsically flawed. This might not be just a bad preamp design, period. This particular CA-7A might need more tune-up or replacement of some parts. Alternatively, some other component(s) of my system should be replaced (e.g., Luxman with dedicated power amp). All specific suggestions and comments on this subject are welcomed.

What is NOT WELCOMED though are comments on what priorities I should or should not have and what type of gear I should or should not use in my system, no matter how obsolete you think they are. You set priorities for your own system and other people set priorities for theirs.

@Almarg: Thanks for the suggestion to use high-capacitance cables. I have A DMM with capacitance test function and will test cables on hand. However, I would not like to sacrifice the bass output for things like soundstage or dynamics so cheap $20 high-capacitance cables might not be the best thing to use…

To all: The preamp got a dedicated power cord five days ago and it results in a DRAMATIC improvement of sound. Missing bass and lower midrange appeared; in fact, in some records I hear too much or “muggy” lower midrange. The cord is nothing special, Audio Thrills with the retail (new) around $70 or so. I didn’t believe in power cords importance for low power consumption gear such as preamps before.

Prophos: If you're not willing to take the positive suggestions and advice as well as a very different viewpoint here than yours, you're on the wrong site.
Your priorities are indeed your own. But to claim dynamics and bottom-octave bass and any kind of reasonable soundstage attributes with a cassette source is silly at best relative to LP and digital sources. Chasing cables and noting capacitance in this implementation is futile. $100 cables will be so compromised and not any less so than $20 cables.

Hope it all works out for you.

I think he is listening, but we just threw too much of an authority at the man, and naturally he doesn't like it. Who would?

Inna: You are right. He's heard enough criticism. Now he's on his own.