Power conditioner or not?

As to the individual who initially asked the question. You may want to consider contacting a design engineer at the manufacturer(s) of your equipment or the equipment that you are thinking about purchasing and posing your question to that individual. (Assuming of course that the manufacturer does not also sell power conditioners and thus is free of a bias based on pecuniary interests) Absent that, stop in at your local university and chat with a professor of electrical engineering. If you contact more than one of those sources, you will likely find uniform answers.

After further listening and critical examination with very familiar material, the conditioner DID rob the audio band of low level information and detail...extended listening is always key!! OOOPs, my bad!

Musicnoise, You "need" to learn that virtually all manufacturers -at all levels-are inclined to say "you need nothing further with our products". Most humans are not their own best critics.