One time trying a phono stage I thought the SDS was the culprit but eventually ruled it out, so count me as having no issues. I do have it placed away from my pre-amp, phono stage and turn table. I believe the manual recommends this.
I also read in the manual that the unit should be 12 inches away from components. Right now I have it on a shelf under my table and above my phono. I am thinking of placing it on the floor beside my couch a few feet away from my stands.
Regarding the cord....I asked that very question many months ago. Evidently there are some Audiogoners that believe a better cord will make a difference. Search through the threads and you may find that thread. I've not experimented with cords, I still use the stock one.
Yes, I was surprised that a power cord could make a big difference, but when auditioning cords, I tried one on the SDS and it did change the sound, dependent on the cord. I use Tara Air cords, and went with the same cord everywhere.