How to reduce power supply noise.

I'd like to hear ideas on reducing the power supply noise
within a CD player. I have found AC conditioning and isolation to make staggering improvemnts to CD playback in my Spectal based system and would like to turn attention to internal improvements.
I noticed the Spectral Audio interview with Robert Harley
indicated much work has been done on their new reference CD player to reduce noise and interaction even further than in past models. Can we do anything with noise, crosstalk & interference in existing CD players?