I have found that power cords can help with noise and EMI I found the biggest improvement in my digital library was my DAC. I have a Krell Digital Vanguard and initially I thought cool an internal DAC great until I got an external RME-ADI-2 DAC running balanced interconnects into my Krell. All I can say is WOW. I love my vinyl but the change in depth, warmth and clarity is amazing!
This is worth every penny of under $1k