Good outlet for amplifiers

I confirmation of others before me, the Furutech GTX-D NCF(R) Ultimate Nano-Crystal Rhodium-Plated AC Duplex Receptacle produced an audible difference.  
In reviewing your system, I do not see power conditioning listed.  I recognize your post focuses on outlet recommendations, but consider a power conditioner within your means from Shunyata or Audience.  Well kept preowned is good.  IMHO, more of an improvement across the board than an outlet.  

@pinball101 Wouldnt I get a better connection, at least to the first outlet, by going directly into the outlet rather than creating a pigtail in the box? That’s what I was thinking and why I would Daisy chain. Because the most important outlet will be the first one where the two amplifiers are set  also, this quad installation is the end of a circuit… So I’m not too worried about other outlets further downstream.

I can't speak to the benefits of direct connection vs the pigtails in line with the connection.  But based on your configuration being at the end of the circuit, I would not bother with the pigtails either.  

I'm not familiar with the isolated grounding you are referencing so I can't speak to that either.

@peter_s  I hear you… But I would also have to construct my own cables in that case. I’m using power cables that have plugs on them.

Your attempting to improve the 'weak link' which is the connection of the PLUG its self.

None of these connection changes will give you more power/high voltage or cleaner electricity or less noise. The only reason for upgraded outlets is for reliability concerns.

Whether ANY of the solutions will give you an audible improvement is doubtful but if you want the absolute best, most reliable connection available eliminate the plug altogether.

Good luck!

There is nothing in NEC code that says the ground has to be installed up or down. The AHJ (Authority having Jurisdiction) in a state can require it to be up or down. In new construction the electrical section in the spec book can require the grounds to be up or down. A hospital project manager can just say one day I want them up.

For years the majority of outlets installed in my area in Hospitals and Healthcare Facilities were down.

The paper clip one was used for the reason in hospitals and healthcare facilities in my area. Story goes, a desk against a wall. Outlet below desk. A paper clip is knocked off from the back of the desk. A cord and plug is not tightly plugged all the way into the outlet. Paper clip falls and lands across the Hot and Neutral blades of the plug. Result, fireworks... What are the odds???

@erik_squires explanation is more the reasoning for the ground up. The stainless steel plate falls off and lands, in most cases, on the plug body and that's where it sets until,... But sometimes if the plug is out a little bit it hits the plug blades. Fireworks!!! Breaker trips right? Not always.

As for the 6/32 trim screw that holds on the plate working loose ??? Well the problem, it was not tight. Not even snug. Whose to blame? The Painter.

The painter? The painter pulls the plates and is responsible to put them back on.

To be clear, there’s nothing good about an outlet plate, especially a metal one coming loose and at best putting the ground up or down is a prayer to the angels at best.