Outlet is "Open Ground" - Is There Still a Safe Way to Connect to My Audio Gear?

@vinylfun 

It is possible what @gs5556 posted above, is possible.

Did you check the other wall outlets in the same room for Open Ground? 

If you have a multi-meter it would be easy to check without removing the outlet from the wall box. You would only need to remove the wall duplex cover plate. Set the meter to AC auto volts. Touch, contact, one test lead probe to the top or bottom of the steel metal outlet box. Insert the other test lead probe in the smaller of the two slots of one of the outlets and check for voltage If no voltage make 100% both probes age making good electrical contact. If still no voltage insert the test lead in the other, longer slot of the two and check for voltage.

If there is a safety equipment ground present you will measure 120V nominal.

Approximate age of the house?

If really old there is a chance the wiring is original and could be old cloth covered rubber insulation. Do not try to remove the outlet. Just pulling the outlet out of the wall box for a look inside could cause the brittle insulation to fall off the wires baring the two conductors.

There is a chance the in wall branch circuit wiring is only two wire. Therein no safety equipment grounding conductor present.

If that is the case, at some point in time the old worn out original 2 wire duplex receptacle was changed out and was replaced with a 3 wire  grounding type outlet.

Use your plug-in circuit tester in the bedroom outlets. What does the tester show? Open Ground?

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Ground"(!)  Without moving everything around to fit the main Power Cable length to a "Grounded" outlet, please is there a safe and best sounding way to still use this outlet to power everything? 

IF there is not any grounded objects within arms length of the equipment and the floor is wood or carpeted there is not a provided path for you to receive an electrical shock through your body. What would you have done if the wall outlet was only a two wire outlet? Used a ground cheater? 

You might want to consider in the near future to hire an electrician and have a new dedicated 20A branch circuit installed for your audio system equipment. 

Also have the electrician check out the Open Ground wall outlet. If it is only a 2 wire circuit, and if the box is deep enough, he can install a GFCI duplex outlet, in place of the 3 wire grounding type outlet. If the box is not deep enough he can buy a new 2 wire duplex receptacle and install it in place of the 3 wire outlet. Or just remove the outlet and install a blank wall plate. 

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Were the faceplate screw in place when you took the reading?

If not install the screw and check it again.

DeKay

Great questions and thoughts - thank you very much.

The house is 63 years old.  Yes, the "Open Ground" duplex outlet was identified with a three prong plug-in outlet tester, before I opened it up.  Inside there are only two sets of two wires for the two outlets; the wires are cloth and rubber covered.  There is no ground wire   The outlets are three prong so presumably were added after the original wiring. 

Other room outlets test as "Grounded," hence my idea to first use one of these outlets and move my audio equipment, furniture, carpets, under lay et al around(!)

Longer term I'm considering having an electrician install a dedicated 20A branch circuit and/or a GFCI duplex outlet...thank you all again for all your kind help.  It is much appreciated.  Enjoy your music! 

The house is 63 years old.  Yes, the "Open Ground" duplex outlet was identified with a three prong plug-in outlet tester, before I opened it up.  Inside there are only two sets of two wires for the two outlets; the wires are cloth and rubber covered.  There is no ground wire 

63 years old, 1962... I imagine the branch circuit wiring is cloth covered NM, Romex. Though going from memory, the two conductor where insulated with TW thermal plastic, PVC insulation. 

It is possible, because of local Fire Codes, Electrical Codes, AHJ (Authority Having Jurisdiction) in your city required houses back then to be wired using BX, steel armored cable. (In 1962 the steel armor was not used as an equipment grounding conductor,) In 1962 it may have still had cloth covered rubber insulation covering the bare conductors.

Yes, the "Open Ground" duplex outlet was identified with a three prong plug-in outlet tester, before I opened it up.  Inside there are only two sets of two wires for the two outlets;

That indicates a convenience outlet branch circuit. More than likely a 15A circuit. The outlet terminals were used for feed through in and out circuit through the box. Good chance there are several wall outlets, and possibly ceiling lights on the circuit.

Shut off the breaker at the panel and check what is dead. Identify with a piece of tape or a post-it at each dead wall outlet.

Turn back on the breaker and check the wall outlets for a ground with your plug-in tester. Upstream, (toward the electrical panel), from the one for your audio equipment may show there is a ground. Down stream will show an Open Ground.

If it is BX don’t assume the integrity of the safety equipment ground. Good chance it will fail in the event of a Hot to ground fault event.  Back in 1962 there were not any 120V 15A or 20A 3 wire grounding type outlets. They were only 2 wire.

My home was built in 1956 and has two wire open ground outlets in much of the house. This is true in my listening space. 

I am a fairly avid follower of posts on AG and realize amps, in general, should be plugged directly into the mains outlet. When I do this, I can actually feel low levels of current on the metal faceplate. Pretty scary.

I have plugged my amp into my Panamax surge protector/power conditioner. The grounding issue was resolved. Hopefully this hasn't impacted the overall sound of the amp. It seems like a decent compromise to not have the scary feeling grounding problem.