They absolutely do!
I had some cheap monster cable RCA's connected and we switched in some Cardas Clear RCA's. The improvement in sonics was very noticeable. In fact CD's sounded better than my streaming front end where before streaming always sounded better.
I bought the Cardas Clear RCA's and put them on my phono stage to the pre amp. I rarely use the CD player so I didn't want to spend 2.5k on another pair!