EMI w/ computer, peri-HD and DAC so close 2 amps

Hello,

A "just wondering" inquiry:

Has anyone experienced EMI and/or RFI interference with their audio equipment/system after installing a computer (in my case MacMini) w/ peripheral HD, and of course DAC?

Things sound good to me now, but I find myself wondering.

And if so, what were its effects? And how did you treat/remedy the problem without resort to pricey S-stones?

Thanks in advance &

:) listening,

Ed