This may be a silly question, but have you looked inside the outlet box to determine if there is a two wire + ground cable entering the box.  Unless your house is very old, it would be surprising not to have a ground wire.  Maybe it's there and not connected properly?  I can't think of another reason to be having an open ground.  Cheers. 

I assume that the receptacle is standard 3-prong and "Open Ground" was read from a plug in outlet tester.

What you can do is remove the outlet and check the ground connections. Sometimes the grounding wire is wrapped around a screw on the box and not to the receptacle and the installer assumed the ears of the outlets would make a good enough ground contact with the box. Although not likely, this can defeat the ground over the years. What is more likely is if there is an insulator between the ears and the receptacle. Then simply remove the insulation. If that grounding conductor is long enough then you can attach it to the green screw of the outlet -- the right way of doing it. If there is not enough wire then an electrician should be called for giving you options if you really need to use that outlet.

@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?

. 

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. 

.

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.

@motown-l  said:

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 face plate. Pretty scary.

On the metal face plate? As in wall metal outlet face plate? A metal face plate should never be used on a 2 wire branch that uses a steel outlet box... Replace all metal wall plates with plastic or non breakable nylon plates.

.

I have plugged my amp into my Panamax surge protector/power conditioner. The grounding issue was resolved.

Model? 

.

So this would work for protection on a two wire outlet? Thoughts...Thanks 

Panamax MD2 2 Outlet Direct Plug In Surge - White

Sorry, the metal faceplate of the amplifier.

@vinylfun said:

So this would work for protection on a two wire outlet? Thoughts...Thanks 

No, it would not.

It also would not protect from transient surges either. The SPD requires an equipment ground connection.  

https://panamax.com/product/2-outlet-direct-plug-in-surge-protector-with-coax/

https://s3.niceforyou.support/products/MD2-C/pdf_MD2-C_manual.pdf

.

https://www.crutchfield.com/p_299MD2/Panamax-MD2.html

https://pdf.crutchfieldonline.com/ImageBank/v20100815120200/Manuals/299/299MD2.PDF

.

@motown-l  said:

I have plugged my amp into my Panamax surge protector/power conditioner. The grounding issue was resolved.

The grounding issue was resolved.

Resolved by using the Panamax surge protector/power conditioner?

Model? 

Does it use an internal isolation power transformer?

You should get the grounding issue fixed, but the only "fix" for this I know of is to use a GFCI outlet and label it with the sticky labels that say "No Equipment Ground." 

However, not ideal and most surge protectors won’t work correctly in this state.  This will however save your ass in case of a short to the chassis. 

I’d suggest you get a cheap-o 3 plug tester like this one and validate that it’s wired correctly, or not, and that the Neutral to Earth value is 2V or less.  Either of these not being true call an electrician.  You might also just want to check the outlet.  It could be the ground wire just came loose, or it might have bee your first surge strip was faulty.  Good to have around especially in a home that's new to you.  Test everything, trust nothing and maybe look at my blog for ideas on good AC for the frugal audiophile

I have had to replace several duplex outlets over the years. Definitely two wire open ground. There is an addition on the house, built in the 1980's. Those outlets do have the typical green grounding cable, but the breaker box (since replaced and upgraded) was still from the 1950's and didn't have provisions for actual grounded outlets, anywhere in the house. 

I don't have access to the model number of the Panamax surge protector, but it's a fairly low end model. All I know is when the amp was plugged directly to the mains, it's metal front cover conveyed some minor current flow and when plugged into the Panamax, it was resolved.

I am not in a position to rewire my entire home either DIY or via a paid professional. I also don't own equipment anywhere near true audiophile or reference level cost or performance.

@erik_squires

You should get the grounding issue fixed, but the only "fix" for this I know of is to use a GFCI outlet and label it with the sticky labels that say "No Equipment Ground." 

This is what NEC code calls for. Had to scroll too far down for to finally reach the correct answer. You can also replace the first receptacle on the circuit with the GFCI and attach the downstream receptacles to "load" and label them per above. This will ensure each receptacle on the circuit is protected by the single GFCI. Or place the GFCI solely on the receptacle in question. 

@ecat026 Said:

This is what NEC code calls for. Had to scroll too far down for to finally reach the correct answer. You can also replace the first receptacle on the circuit with the GFCI and attach the downstream receptacles to "load" and label them per above. This will ensure each receptacle on the circuit is protected by the single GFCI. Or place the GFCI solely on the receptacle in question. 

Check my post on 06-26-2025 at 10:40am 

FYI,  2020 NEC 406.4 (D) (2) (a) says an old two wire receptacle can be replaced with a new 2 wire receptacle when there is not an equipment ground present. 

Would a GFCI outlet be better for his situation feeding his audio equipment? Yes... If the box is deep enough... IMO a new  20A dedicated branch circuit would be better. My bet the OP will hear a difference, for the better.  

Back in the old days some of the steel boxes used for wall outlets may not be deep enough for the installation of a GFCI duplex receptacle. (He has 4 cloth covered rubber conductors in the box as well.) The electrician he hires will check the box for fit. I am sure the electrician will know what he can do.

FWIW...

There are other options to add GFCI protection to the 2 wire convenience outlet branch circuit. One, is to install a GFCI breaker in the electrical panel. (providing the branch circuit is not part of a multiwire branch circuit.) That would also allow a 3 wire grounding type receptacle to be installed for his audio system. (Label would be required on the outlet cover plate.)  Just a guess, more than likely all the duplex outlets on the 2 wire branch circuit have 3 wire grounding type outlets installed on the 2 wire circuit. Just a guess there may be some ceiling lighting on the circuit as well.

What the OP should not do himself is mess with the old branch circuit wiring. Especially if the insulation on the wires is old cloth covered rubber. 

Best regards,

Jim

@jea48 

The replacement GFCI breaker is a good alternative, if somebody manufacturers a retrofit for what is likely a 60 year old breaker box. Ideally, OP would hire an electrician to install a dedicated 20 amp circuit and verify that the sub and main panels are properly grounded too. 

I figured a replacement GFCI outlet was the simple "fix" he requested, however, his wiring does add another layer of complexity. The grounding issue could easy snowball into a large, expensive project.

Agreed, the best fix is to hire an electrician. 

**406.4(D)(2) Non‑Grounding‑Type Receptacles.**

Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(2)(a), (b), or (c):

(b) A non‑grounding‑type receptacle(s) shall be permitted to be replaced with a GFCI‑type receptacle(s). These receptacles or their cover plates shall be marked “No Equipment Ground.” An equipment grounding conductor must not be connected from the GFCI‑type receptacle to any outlet supplied downstream.

(c) You may also install a grounding-type (3‑prong) receptacle without a ground, if it is protected by a GFCI (breaker or receptacle). In that case, the receptacle or cover plates must be labeled “GFCI Protected” and **“No Equipment Ground.”

@ecat026 said:

The replacement GFCI breaker is a good alternative, if somebody manufacturers a retrofit for what is likely a 60 year old breaker box.

The OP said the house is 63 years old. (Built in 1962).  If the electrical panel is the original one, IMO, the OP should be worried more about the old panel than the non grounded outlet his audio system is plugged into, when it comes to his safety. You are correct about the GFCI breaker though. I didn’t consider the panel could still be the original one that was installed in 1962. That doesn’t say the panel was made in 1962. I could be from the late 1950s. Who knows?

As for this:

**406.4(D)(2) Non‑Grounding‑Type Receptacles.**

Where attachment to an equipment grounding conductor does not exist in the receptacle enclosure, the installation shall comply with (D)(2)(a), (b), or (c):

I looked at that this morning and thought to myself wheres the (a) ? So I pulled out my 2020 NEC code book and read 406.4 (D) (2) (a) . I seen the little triangle beside (a)... (a) was deleted in the 2020 NEC. 2017 NEC was the last code Edition allowed. The OP lives in Maryland. To date the State of Maryland.is still working under the 2020 NEC code. 

.

the best peace of mind you will have is to get a quote to rewire your home. People over the years have possibly "rigged" wiring to work any old way they could. I've seen many houses get worked on over the years. In every case wiring was faulty or redone by wannabee home owners. You'll sleep better at night knowing your home is safe. Some things are better left to a pro. Your insurance company will be happy too. Joe

@vinylfun 

I hope the electrical service and electrical panel in your home is not the original installed in 1962. 

As for your safety concerns using the ungrounded outlet your audio system is plugged into, you could buy one of these to feed the power to your audio system for now.

Example of:

GFCI plug-in pigtail  

More examples to choose from.

https://www.homedepot.com/b/Electrical-Electrical-Cords-Extension-Cords-GFCI-Plugs/N-5yc1vZcger

.

All I know is when the amp was plugged directly to the mains, it's metal front cover conveyed some minor current flow and when plugged into the Panamax, it was resolved.

I am not in a position to rewire my entire home either DIY or via a paid professional. I also don't own equipment anywhere near true audiophile or reference level cost or performance.

@motown-l  I understand money is a concern, but this sounds bad.  Not saying you need to rewire your home, but it sounds like a lifted neutral which can cause all sorts of electrical and life safety issues. 

Strongly suggest you get the cheap-o tester I recommended and see what it t4ells you, then consult with an electrician.  It's quite possible this is a small fix, and if it's a major fix it may well save your home. 

Thank you for the helpful additional insights, thoughts and recommendations.

Good news!  The home's current main panel was put in about 5 - 10 years ago. The home's prior owner is a builder.  He lived here 22 years and was renovating all over, up to a few months before he sold in 2023.  

Today I'll get a Husky GFCI plug-in adapter for the Open Ground outlet, to add some safety, if not protection against surges...Next I'll look in to an electrician installing a dedicated power circuit for the audio equipment and/or doing a full home re-wiring as needed...thank you. 

@vinylfun +1 for the dedicated line. I ran one to my listening room and noticed the system sounded quieter.