Where to purchase cables?

DH Labs Silver Sonic Cables with a 30-day trial.

Tellurium low budget like the blue and black are very very good.if you can find used.

I agree with @lak who posted above about Veritas Cables. I started with one set of their Magnus XLR cables and love it so much that I just ordered a set of their higher end Argentum R silver RCA cables. I'm also considering power cables and maybe a few others from them. Just very impressed with their sound so far, as well as their customer service.

I can also recommend other small brands like Audio Art and Triode Wire Labs, they both offer great value. 

Audiogon and USAudiomart both have lots of other nice options. I enjoy Black Cat Cables, Cerious, Decware, Audience, Waveform Fidelity, and DH Labs among others.