Digital cables going in Preamp is this wrong?

I have a pair of JPS Superconductor digital cables that have been sitting up many years. Plugged them in from a tube Oppo CD player into tube amp and its sounds good. I thought it would sound bad because ohm's were different and not an analog cable. Am I missing something?

No, you're not missing anything. Digital cables can work fine when conducting analog audio signals. Their 75 ohm or 110 ohm "characteristic impedance" (for unbalanced and balanced cables, respectively) is not directly relevant at the frequencies of analog audio signals. (It may have indirect relevance mainly due to the fact that capacitance is a major factor affecting the "characteristic impedance" of a cable). And while a digital cable conducting an analog signal can certainly sound different than most interconnects that are intended for analog applications, analog interconnects can of course sound different from each other as well.

So whether a digital cable will sound better or worse than a given analog cable in a given analog application will tend to be dependent on the designs of the components that are being connected, as well as on listener preferences and the sonics of the overall system, and therefore won't usually have a great deal of predictability.

Enjoy! Regards,
-- Al