Improper ground

Indeed - I did mean "shocked..."

Electrician had "really shaky hands" and I was nervous watching him attach my $144 Oyaide R1 AC Receptacle.

LOL, can you imagine what was going through his mind...
What kind of a nut would spend $144 bucks for a receptacle. He probably was thinking if I scratch this damn thing this guy is going to want me to buy him a new one...... LOL....

I am surprised the electrician, when learning you invested $144 in the receptacle, did not try to talk you into installing a new dedicated 20 amp branch circuit line all the way back to the electrical panel. Labor cost may not have been that much more than all that fishing that went on.

His helper got electrocuted when trying to grab the fishing wire thru the cutout in the wall of the old outlet. On several occasions I offered to switch the breaker off because he was just charging ahead with live wires.

Well not quite electrocuted, but shocked..... Stupidity on their part. The circuit should have been turned off. There was no reason to work it hot. In fact working it hot may have added time to the job.
......

On several occasions I offered to switch the breaker off because he was just charging ahead with live wires.

Electrician had "really shaky hands"

Somehow I think there is a connection there (no pun intended)!

His helper got electrocuted when trying to grab the fishing wire thru the cutout in the wall of the old outlet.

Sure hope you mean "shocked" and not "electrocuted." :)

Regards,
-- Al

Turns out they used two wire cable to string up my circuit after the first outlet in the chain. So no ground was present because it wasn't in the power cable! Had to cut the box out; drill two holes in the corner walls to fish the cable thru; cut the 2 wire out and fish the new 12AWG Romex between the 1st and 2nd receptacles.

Electrician had "really shaky hands" and I was nervous watching him attach my $144 Oyaide R1 AC Receptacle. His helper got electrocuted when trying to grab the fishing wire thru the cutout in the wall of the old outlet. On several occasions I offered to switch the breaker off because he was just charging ahead with live wires. Cost me $150 for 1.5 hours work but some of that was entertainment.

The remaining 3 outlets are still improperly ground in the chain but I only plug a cable modem and router into them...

For $5 you can buy a 3 prong circuit tester, that way you can tell for sure what's grounded, determine proper phase etc.

I would suggest that you do get a qualified electrician and have him check out the whole electrical system. Improper grounding could be an indication of other existing problems from poor connections to improper design. Safety is key, the amp can be replaced.

Your amp will be grounded when it is connected to the grounded source (via the I/C).
But... you want to be on the safe side, don't you? So, ask the manufacturer!

Have you considered calling the manufacturer of your amplifier who would certainly be the most knowledgeable party about the specifics of your amplifier?