So would this create noise and issues with digital based gear? I doubt it. A phono stage is supplying 50 db or so of gain into a relatively high impedance so picking up garbage is much easier than most other components in a home hifi rig. So the SMPS in the Mini can sound worse than if the Mini had an LPS instead. I can stick the foil shield between the devices and distortion is gone completely. I connect an alligator clip to one corner and the other to a neutral ground lead on a power strip. I rigged a temporary fix by taping some aluminum foil to the back of a legal pad.
Just messing with things now, I have him plug it back up and bring it online. Okay so on a hunch, I shut down and unplug the Mini. The PS side of the Mini is next to the phono side of the preamp. Sitting next to it about 6-8 inches away is the 2011 Mac Mini he uses for computer based audio. I'm thinking about and noticed when I came in he had re-arranged the gear on his shelf. I suspect a bad tube or a capacitor having gone bad. Sure enough it seems okay at first, but high levels cause an odd distortion, sometimes even warbling and motor boating. My good audiophile friend complains that something may have happened to his tubed phono stage. It was arrived at with total subjective listening methodology.
