I'm starting to look at maybe upgrading cables in my system. Here is what I'm using on my digital playback side. See if you see a weak spot and what you would upgrade to.

CD to DAC--------------Audioquest VDM-3 digital coax cable
DAC to Headphome Amp-----ZU Audio Gede RCA cables
Headphone Amp to Int. Amp-----XLO HtPro RCA cables