How to ground an AV receiver

[Daneurys]

Still need an answer about the power cord plugged into the wall outlet- is the outlet two prong, or three? You also haven't posted about what happens if you eliminate the Panamax. If you don't try it without the Panamax, you're not eliminating all of the possible causes.

Millions of pieces of equipment are operating without a surge protector and they aren't puking, so don't worry about your equipment if it's used without it for a few minutes.

Get an outlet tester- doesn't need to look exactly like this one, but it does need the three lights. If you see anything other than two amber lights, your outlet and/or electric service needs to be repaired.

You have a ground loop.

The outlet is 3 prong. I tried without the Panamax and the hum is still present. I also tested the outlets and they test fine.

 

[markw]

If I disconnect the RCA's from the receiver to the Parasound the speakers would not hum. The speakers will only hum if the RCA's from the receiver to the Parasound is connected. Please advice.

Well, that shows that the parasoud is functional. But, it does show that there's a grounding issue between the receiver and the parasound. These can be a beeyotch to work out, as you're finding out.

 

[Daneurys]

Well, that shows that the parasoud is functional. But, it does show that there's a grounding issue between the receiver and the parasound. These can be a beeyotch to work out, as you're finding out.

Do you think that by any chance that a RCA hum eliminator would solve the problem

 

[TLS Guy]

The outlet is 3 prong. I tried without the Panamax and the hum is still present. I also tested the outlets and they test fine.

You have a common problem with power amps. I never ground a power amp via the AC lead. The reason is the problem you are having. Pros do not generally ground power amps, except to the pre amp or mix desk. Your ground lifter only lifts signal ground and not chassis ground.

Best practice is to ground the preamp, which in your case is the receiver and keep the power amp bonded to the receiver and lift the ground to the power amp entirely. I always ground the preamp and make sure the power amp stays connected. The power amp is then grounded though the shield.

I suspect your receiver is two prong of the so called "double insulated" variety. In domestic systems this unholy mix of grounded and double insulated units often results in the problems you are having.

For a test lift the ground to your power amp. I'm willing the bet that the hum stops.

If it does I will show you how to ground your receiver. If you are worried that your power amp will not always be connected to your receiver I will explain to you how to bond your receiver and power amp chassis. Either way the ground of the AC cord to the power amp will need to remain lifted.

 

[markw]

dunno, but it's worth a try, the shield of RCA interconnects is where the problem is created.

Try it, but be prepared to send it back.

it would be interesting to see if this problem existed with another power amp, though.

 

[Daneurys]

You have a common problem with power amps. I never ground a power amp via the AC lead. The reason is the problem you are having. Pros do not generally ground power amps, except to the pre amp or mix desk. Your ground lifter only lifts signal ground and not chassis ground.

Best practice is to ground the preamp, which in your case is the receiver and keep the power amp bonded to the receiver and lift the ground to the power amp entirely. I always ground the preamp and make sure the power amp stays connected. The power amp is then grounded though the shield.

I suspect your receiver is two prong of the so called "double insulated" variety. In domestic systems this unholy mix of grounded and double insulated units often results in the problems you are having.

For a test lift the ground to your power amp. I'm willing the bet that the hum stops.

If it does I will show you how to ground your receiver. If you are worried that your power amp will not always be connected to your receiver I will explain to you how to bond your receiver and power amp chassis. Either way the ground of the AC cord to the power amp will need to remain lifted.

When you said "For a test lift the ground to your power amp." What do you mean.

 

[TLS Guy]

When you said "For a test lift the ground to your power amp." What do you mean.

I mean you use one of these.

Do not connect the grounding lug to the receptacle.

Problems occur with power amps especially when the ground wire in the AC lead is connected.

I think this occurs as power amps are high current devices, and even in a lot of expensive power amps, the ground plane is just not beefy enough. In a large number of power amps the ground plane layout and construction is laughable. This is an area that get a lot of mods from the DIY community in a huge number of amps. I would say the S/N of the majority of power amps can be improved by DIY attention.

As HT gets more complex, grounding becomes a bigger issue.

In my own case I use the now preferred star cluster ground system. This has been refined over time, and now there is no hum at all from any speaker, even with your ear stuck in them. The whole system is now totally hum free. Unfortunately this approach is not possible in most domestic situations.

I would say my grounding system is now complete for a year now. It took about five years to get that star cluster perfected, although is was what would be considered good at outset. However I wanted to see if total absence of AC noise was possible. I have shown that it is, but it takes a lot of effort.

 

[highfigh]

The outlet is 3 prong. I tried without the Panamax and the hum is still present. I also tested the outlets and they test fine.

Tested for reverse polarity and lifted neutral, too?

 

[highfigh]

I mean you use one of these.

Do not connect the grounding lug to the receptacle.

Problems occur with power amps especially when the ground wire in the AC lead is connected.

I think this occurs as power amps are high current devices, and even in a lot of expensive power amps, the ground plane is just not beefy enough. In a large number of power amps the ground plane layout and construction is laughable. This is an area that get a lot of mods from the DIY community in a huge number of amps. I would say the S/N of the majority of power amps can be improved by DIY attention.

As HT gets more complex, grounding becomes a bigger issue.

In my own case I use the now preferred star cluster ground system. This has been refined over time, and now there is no hum at all from any speaker, even with your ear stuck in them. The whole system is now totally hum free. Unfortunately this approach is not possible in most domestic situations.

I would say my grounding system is now complete for a year now. It took about five years to get that star cluster perfected, although is was what would be considered good at outset. However I wanted to see if total absence of AC noise was possible. I have shown that it is, but it takes a lot of effort.

How do you ground the chassis, which is supposed to be grounded when a three prong power cord is used? Less expensive equipment is more likely to have a problem, but if the amp comes with a two prong cord, the power transformer usually has the neutral leg connected to chassis.

 

[highfigh]

Do you think that by any chance that a RCA hum eliminator would solve the problem

How old is your house? Does your local inspector/city building department require much in terms of National Electrical Code compliance? If not, if they allow homeowners to freely work on their own electrical service and if many people have added/modified existing circuits, I would expect noise. Also, the way the outlets are connected can matter- if they were "back-stabbed", I would change that ASAP because heavy load causes the tiny contact area to become hot and it can cause the spring clip to relax. When this happens, the connection quality suffers and wires can corrode. If you were to shut off the power and measure the resistance between the neutral & ground at your outlets, I would bet that you'll see a wide range of resistance values and that's not good.

If you use a hum eliminator, don't use the cheapest one you can find. If it will go on the power cord, cheap ones can cause safety issues and if it's on the audio path, the cheap ones degrade the sound quality. IsoMaxx, by Jensen Transformers, are among the best. I have an adapter from a company called Edcor that I'll be using soon, but I don't have experience with their isolators. Their tech support person was very informative and the info was accurate.

If you look on the rear of the Parasound, you should see a large screw near the lower right corner. If it has a symbol that's similar to this, use that screw to attach a ground wire to the junction box (if it's metal) or to the receptacle's ground using a ring terminal, secured with the wall plate's screw.

 

[OriginalCin]

You have a common problem with power amps. I never ground a power amp via the AC lead. The reason is the problem you are having. Pros do not generally ground power amps, except to the pre amp or mix desk. Your ground lifter only lifts signal ground and not chassis ground.

Best practice is to ground the preamp, which in your case is the receiver and keep the power amp bonded to the receiver and lift the ground to the power amp entirely. I always ground the preamp and make sure the power amp stays connected. The power amp is then grounded though the shield.

I suspect your receiver is two prong of the so called "double insulated" variety. In domestic systems this unholy mix of grounded and double insulated units often results in the problems you are having.

For a test lift the ground to your power amp. I'm willing the bet that the hum stops.

If it does I will show you how to ground your receiver. If you are worried that your power amp will not always be connected to your receiver I will explain to you how to bond your receiver and power amp chassis. Either way the ground of the AC cord to the power amp will need to remain lifted.

I know this thread is from 5 years ago, but I have exactly this same problem with all of the same symptoms. I’m getting some hum connecting an Emotiva power amp to a Denon AVR-X4500H. After running a couple of tests for the Emotiva folks, they said that the issue requires grounding the AVR and the chassis of their power amp together.
Five years ago you mentioned that you’d show the original poster how to bond the receiver and power amp — I’d appreciate the same tutorial.

 

[TLS Guy]

I know this thread is from 5 years ago, but I have exactly this same problem with all of the same symptoms. I’m getting some hum connecting an Emotiva power amp to a Denon AVR-X4500H. After running a couple of tests for the Emotiva folks, they said that the issue requires grounding the AVR and the chassis of their power amp together.
Five years ago you mentioned that you’d show the original poster how to bond the receiver and power amp — I’d appreciate the same tutorial.

Well first of all a system needs one ground. It is resistances between grounds that cause ground loop hum.

To bond your Denon, you need to place a stout cable between the Denon and Emotiva. You might have to find a screw on the chassis of the Emotiva, scape a little paint and use a spade connector. On the receiver you can use the turntable ground, if it has one. It is best if the Denon is connected to ground, but if it is two pin double insulated then make the ground at the Emotiva.

Now If it still hums then you need to disconnect inputs to the Denon one by one, to isolate the loop. Potent causes are cable systems/satellite TV, and Ethernet connections..

So please carry this out and report back. A logical plan will help isolate the grounds that have resistance between them.

 

[OriginalCin]

Well first of all a system needs one ground. It is resistances between grounds that cause ground loop hum.

To bond your Denon, you need to place a stout cable between the Denon and Emotiva. You might have to find a screw on the chassis of the Emotiva, scape a little paint and use a spade connector. On the receiver you can use the turntable ground, if it has one. It is best if the Denon is connected to ground, but if it is two pin double insulated then make the ground at the Emotiva.

Now If it still hums then you need to disconnect inputs to the Denon one by one, to isolate the loop. Potent causes are cable systems/satellite TV, and Ethernet connections..

So please carry this out and report back. A logical plan will help isolate the grounds that have resistance between them.

Thanks! I’ll go follow those instructions and let you know how it goes.

Additional bit of info — both the receiver and the power amp are plugged into a Panamax M4315-Pro power conditioner. I noticed that the Panamax has its own grounding post (currently unused) — would it make sense to connect both the receiver and the power amp to that ground?

 

[Speedskater]

Try it without the Panamax, and make sure that everything is plugged into the same wall outlet.

 

[TLS Guy]

Thanks! I’ll go follow those instructions and let you know how it goes.

Additional bit of info — both the receiver and the power amp are plugged into a Panamax M4315-Pro power conditioner. I noticed that the Panamax has its own grounding post (currently unused) — would it make sense to connect both the receiver and the power amp to that ground?

It all depends on what is plugged into the Panamax, and which units have two pin AC plugs and which have three pin.

 

[highfigh]

I know this thread is from 5 years ago, but I have exactly this same problem with all of the same symptoms. I’m getting some hum connecting an Emotiva power amp to a Denon AVR-X4500H. After running a couple of tests for the Emotiva folks, they said that the issue requires grounding the AVR and the chassis of their power amp together.
Five years ago you mentioned that you’d show the original poster how to bond the receiver and power amp — I’d appreciate the same tutorial.

What Emotiva model do you have?

WRT the original poster, who never showed the model of his amp, either- if we don't know what's in the system, we can't help because not all equipment is designed the same. If the OP has/had the Parasound A23 or other model from the Halo line, he should have read the damn manual because those amplifiers have a ground lift switch, specifically for solving this problem.

 

[OriginalCin]

My amp is an Emotiva XPA-7 Gen 3. It doesn’t have a grounding switch or post, which is why Emotiva themselves recommended the same binding of my Denon AVR-X4500H and the XPA-7 with a grounding wire that this forum recommended — and they said I should just pick a chassis screw to use, since there isn’t a proper grounding post on their amp.

I should add that I’m test-driving the Emotiva. If it proves to be lots of diy tweaks to get it working in my setup, I’d rather return it and get an amp that’s a better match — recommendations welcome!

XPA-7 Gen3 7 Channel Audiophile Home Theater Power Amplifier

Premium seven-channel audiophile home theater power amplifier (300 watts/channel into 8 Ohms). The foundation of a superb 7.1 channel home theater system, or a high-end 5.1 channel system with bi-amped front speakers.Designed, assembled, and tested in the USA.

emotiva.com

 

[Bsbllfit7]

Same issues her except denon avr-x6400 and emotiva Xpa 2 gen 3. Neither the denon OR the emotiva have a third prong for the ground at the main units. I do have 3 prong cables that I could use but there won't be any benefit without the 3rd prong on the amp or receiver, correct?

 

[OriginalCin]

Thanks! I’ll go follow those instructions and let you know how it goes.

Additional bit of info — both the receiver and the power amp are plugged into a Panamax M4315-Pro power conditioner. I noticed that the Panamax has its own grounding post (currently unused) — would it make sense to connect both the receiver and the power amp to that ground?

I never followed up on this thread. The recommendation worked! After connecting a grounding wire to the Denon grounding post and a chassis screw on the Emotiva amp there’s no longer any speaker buzz.

 

[OriginalCin]

Same issues her except denon avr-x6400 and emotiva Xpa 2 gen 3. Neither the denon OR the emotiva have a third prong for the ground at the main units. I do have 3 prong cables that I could use but there won't be any benefit without the 3rd prong on the amp or receiver, correct?

Get a grounding wire and connect the Denon grounding post to any chassis screw on the amp. Got rid of my speaker buzz. I picked up a basic grounding wire from Amazon.
Phonograph Turntable Ground Wire... https://www.amazon.com/dp/B07Z9WB7W6?ref=ppx_pop_mob_ap_share