Your Favorite AC Outlets

Try either Synergistic Research Tesla Plex SE or Oyaide; the red colored one. Both of these outlets are fantastic sounding

Another vote for Porter port. My jaw hit the floor once I gave this a listen. Everything significantly improved. The best part was that it only cost me $35. I would rank this as the best improvement for the cash I have heard on my rig.

Without getting technical (and I might not be capable of that) for the money I find the Porter Ports very hard to beat although there are a few outlets out there that probably sound better but at a much higher cost.
Remember this is all very subjective and equipment dependent.

Mofi, thanks! In answer to your question: First, the Porter Ports are apparently not isolated ground receptacles, because IG receptacles are required to have a small triangle symbol on their face, and are usually orange in color.

However, if I understand correctly that what is running from the outlet back to the service panel is just a three-wire cable that is not enclosed in metal conduit, and that is connected to nothing else along the way, then it seems to me that you are getting pretty much all of the benefit that an IG receptacle would potentially provide. The idea behind an IG configuration is to avoid connections between the AC safety ground contacts on the outlets and any ground point other than at the service panel, which is what you've got.

A minor point of difference, though, which I suspect is unlikely to be of any practical significance: RF noise picked up by the metalwork of the junction box itself, acting as an antenna, could be conducted onto the safety grounds in your configuration, but might be effectively isolated from the safety grounds by an IG receptacle. RF wouldn't be directly audible as noise, of course, but might have audible consequences by intermodulation or other effects that can occur in the component circuitry.

Also, I'll mention that conduit vs. no conduit can have its own set of pretty much unpredictable tradeoffs. It can be beneficial as a result of shielding effects, but as explained in the Bill Whitlock quote I provided above it can pick up noise from conduit or other metal it comes in contact with, and couple that noise onto the wires it contains.

Finally, if an IG receptacle were to be installed where there is no conduit or other path for the junction box and the non-isolated metal parts of the outlet to be connected to ground, aside from via the ground wire in the cable, from a safety standpoint and I suspect also from a code compliance standpoint the isolated and non-isolated ground connections of the outlet would have to be connected together. Which would essentially convert the IG receptacle into a non-IG receptacle.

Hope that clarifies more than it confuses :-)

Best regards,
-- Al

Porter Ports are a Hubbell hospital grade outlet and are not an isolated ground design; just FYI. And running dedicated lines does not mean isolated ground. There is a lot of information on the web pertaining to the wiring of isolated ground circuits. Such as https://www.google.com/#q=wiring+diagram+for+isolated+ground+receptacle.

Also a good method to minimize the occurrence of ground loops is to plug components into a high quality power strip but be sure not to overload the circuit. And of course one must be cognizant of local electrical codes.

Chuck