Isolated Ground causes ground hum.

What do you think about the use of Isolated Ground Receptacle in this case.
Thanks

First, what is an IG, (Isolated Ground) receptacle?
A receptacle where the female equipment ground contact is isolated electrically from the receptacle supporting back strap.

What is the intended use of an IG receptacle?
To provide a connection to the equipment ground contact of the receptacle using an insulated equipment grounding conductor run with the branch circuit wiring back the the electrical panel the branch circuit is fed from. The insulated equipment grounding conductor connects to the ground bar in the electrical panel. (Exception: NEC allows the insulated equipment grounding conductor to pass through a sub panel and connect to the ground bar in the Main electrical service panel)

IG receptacles are used in commercial and industrial occupancies where metallic electrical conduit is used for branch circuit wiring. The idea is noise maybe traveling on the metallic conduit. The IG receptacle equipment ground contact is isolated from the metallic conduit. IG receptacles were popular in the 1970s, 1980s, maybe 1990s, but not so much in the last several years.

Two equipment grounding conductors are required when using an IG receptacle. One (insulated) for the ground terminal/ground contact of the receptacle and the other to ground the receptacle supporting back strap. Metallic conduit is an approved equipment grounding conductor per NEC Code. Where the conduit is not to be used as the equipment grounding conductor a separated equipment grounding conductor is pulled in the conduit and bonded, connected to the metal receptacle rough in box.

IG receptacle Connected to a Romex branch circuit?
Serves no purpose. If the Romex is terminated in a metal box Code says the equipment grounding conductor in the Romex must be bonded, connect, to the box. A grounding pigtail is also connected to the Romex equipment grounding conductor and connected to the IG receptacle equipment grounding terminal. If a plastic box is used NEC allows an IG receptacle but requires a non conductive receptacle cover plate shall be used.
Jim

Thank you Jim,
Calvin

OK, so yes, you just created your own ground loop. :)

What you can do: 

Add more ground rods.
Bond them to house ground rod farmRun 1 ground wire directly to the ground rods, and use that for your outlets.

Then run phono grounds like normal, from device to device.

@ erik_squires

Add more ground rods.
Bond them to house ground rod farm. Run 1 ground wire directly to the ground rods, and use that for your outlets.

Not sure what you are recommending to the OP. Would you please expand.
NEC requires the equipment grounding conductor to be installed in the same raceway or part of the same cable assembly, (Example Romex).
NEC does allow an Auxiliary Grounding Electrode. NEC 250.54...  I wouldn’t recommend it. It supplies a path for lightning to enter the OPs home.

2008 NEC—250.54

Auxiliary Grounding Electrodes.

One or more grounding electrodes shall be permitted to be connected to the equipment grounding conductors specified in 250.118 and shall not be required to comply with the electrode bonding requirements of 250.50 or 250.53(C) or the resistance requirements of 250.56, but the earth shall not be used as an effective ground-fault current path as specified in 250.4(A)(5) and 250.4(B)(4).

https://www.ecmag.com/section/codes-standards/significant-changes-nec-2008-0
The Aux grounding Electrode Shall connect to the branch circuit equipment grounding conductor. Lightning loves an Aux grounding electrode.

.

https://www.youtube.com/watch?v=WlnFNTay-9Q
Jim

I would think long and hard about adding the ground rods.  If you did get hit by lightning or gave an electrical fire, it’s a sure bet your homeowners insurance may be quite reluctant to cover the loss.  To be sure, I would have a local certified and licensed electrician check out your wiring set up.