Does an Audioquest Niagra 1200 limit amplifier dynamics?

@j-wall Very helpful. I could get the PS Audio on trial, but it would be nice to measure first before laying down thousands. 

I just completed a test with my Niagara 1200. I did not detect a difference in the quality of music when I connected my Luxman 590 AX II Integrated into the Niagara 1200 High Current outlets vs the other outlets on the Niagara 1200, vs my dedicated 20 amp wall outlet. I have not owned or auditioned it but I agree with markiew ((above), the Puritan Audio PSM 156 could be the answer to several issues that others are having.

I have the Puritan 156 and the Isotek Sigmas EVO3, and while the Isotek is good, the Puritan is better (and less expensive).

I have had a few (including the president of Earthquake Joseph Sahyoun directly) of different amp manufacturers (Simaudio, Bel Canto), tell me go directly to the outlet and bypass power conditioners with an amp. I had a few lengthy conversations with Joseph or Earthquake regarding this very thing and he was absolutely ADAMANT about never ever plugging his amp into any power conditioner.

Once I unplugged my Simaudio Titan from my Furman Elite 20pfI and went direct to the outlet I noticed immediate improvements! It was crazy actually how much clearer and livelier the sound becamse. This was after reaching out to Sim directly about this. That's good enough for me...

Not all power "conditioners" are created equal nor are any two home/power delivery situations identical so there is no universal answer to your question. It also depends on the amp (class A or A/B). I have a Niagara 1200 in one system and I notice no difference with the amp plugged in to the 1200 vs amp plugged directly in to the wall. Therefore, you could surmise that it "does no harm" or that it does nothing at all.