Would it make sense and be safe to put power conditioner in front of PS Audio regenerator?

Yeah, after midnight it is almost always better. Problem is that you have to keep the volume down, though I can listen at moderate level at any time of the day, the building is built quite well.

@piobguy 

Good points. Thank you.

(sorry about the double post earlier)

My response to this is more sociological than technical.

People don't engage with hobbies solely to optimize measurable outcomes. If they did, nobody would buy mechanical watches. Nobody would collect vinyl. Nobody would restore classic cars. Nobody would shoot film photography. Nobody would buy Allen Edmonds (waht I wear) instead of a less expensive shoe.

The enjoyment is partly in the object, the ritual, the craftsmanship, the exploration, and the community (virtual or "real").

Can we hear the difference? Maybe.

Do we perceive a difference? Possibly.

Is part of why we do this the pursuit of that occasional "This is it. This sounds amazing!" moment? I certainly hope so.

If the hobby were only about what can be proven on a graph, most of the fun would disappear. The pursuit, the experimentation, and the occasional discovery are part of what makes audio enjoyable in the first place. (At least for me)