Kind of a dumb question...

Use the best one from your source to the pre.
Good listening!

what do you mean by "not of the same quality" ??

if one cable is better than another, in what way ??

can't answer this question without the facts.

without a criterion, cables are different, not better than each other.

i have reviewed many cables and while i hear differences, i would not say one brand is better than another.

perhaps you prefer one to another. why ?

i will give a general perspective:

consider the interaction between cable and component.

as you said, it is easy to test the cables.

just use them between dig. source and pre and pre and amp.

there are only 2 possibilities. one will be preferable.

In two of my three systems the better sound is achieved between my amp and preamp. I do believe at times it’s a system dependent thing.

Second Myraj, the better cable from the CD to Pre, the earlier in the chain, the more significant the impact. You could, of course, listen for yourself. Good Luck!

What about a third possibility?

No preference because no difference noticed.

The rule of thumb is that there is no rule of thumb. You have to experiment and see which way you like it best, not me or anyone else!!!!

With passive preamp there is a general rule that lower capacity (often shorter and better) cable between preamp and amp works better.
With active You can experiment and find out which combination You like most.
But don`t expect a "HUGE" difference from a cable. A decent cable is all You need.

Mr. Tennis is dead on, much to consider and if you ever do a cable shootout make detailed notes

My thought is to use the better cable between pre and amp because then all sources will benefit from the better cable. my 2 cents

Mr Tennis very very good answer.

If you can hear an audible difference between one configuration and the other then this will be an important health check of your system! An audible difference almost certainly means you have a problem either with your system or one of the interconnects is faulty.

Well designed, well matched and properly functioning audio equipment should not change audibly with different interconnects.

Thanks for the input.

Shadome - I haven't gone totally over to the audiophile dark side, but even I can hear the difference in (some)cables. The question for me has always been - is the difference significant enough to justify the cost of the upgrade! Nine times out of ten I have to say "no".