Line noise in speakers?

[Redbone]

I have had a re-occuring problem with noise from other electrical devices in my home coming through my speakers. At times when I have the Pro-logic II mode on I hear pops and crackles. It is not a ground loop hum as it is not present all the time.

I have tried everything to correct this including voltage regulators, Line Conditioners and disconecting my subwoofer to no avail. I am running out of things to try. Next I will try a cable coax isolater and see if that works?? The noise is very aggrivating and seems particularly bad at night. I do live in a duplex and share many of the same lines and cable runs as the guy next door. My NAD receiver has a three pronged plug and I already tried a cheater plug which did not work either.

I am convinced this is a grounding problem, as the noise sounds like a very loud pop sometimes and at other times it is just a quieter static noise, similar to the crackling of a dirty record. But it is not constant it only appears intermittently.

I don't know which direction to turn in as I am running out of options. I had heard that some NAD receivers had grounding problems specificaly the new 753 763 773 and I am considering getting rid of my 753.

It is important to understand that It is not a humming ground loop that is constant but a popping or crackling that appears for a split second then re-occurs every minute or so throughout the night.

I have lost handfulls of hair over this problem as I just finished setting up this new H/T system and paid $4000 for something I can't really enjoy to the fullest.

Any help is greatly appreciated.

 

[mtrycrafts]

I have had a re-occuring problem with noise from other electrical devices in my home coming through my speakers. At times when I have the Pro-logic II mode on I hear pops and crackles. It is not a ground loop hum as it is not present all the time.

I have tried everything to correct this including voltage regulators, Line Conditioners and disconecting my subwoofer to no avail. I am running out of things to try. Next I will try a cable coax isolater and see if that works?? The noise is very aggrivating and seems particularly bad at night. I do live in a duplex and share many of the same lines and cable runs as the guy next door. My NAD receiver has a three pronged plug and I already tried a cheater plug which did not work either.

I am convinced this is a grounding problem, as the noise sounds like a very loud pop sometimes and at other times it is just a quieter static noise, similar to the crackling of a dirty record. But it is not constant it only appears intermittently.

I don't know which direction to turn in as I am running out of options. I had heard that some NAD receivers had grounding problems specificaly the new 753 763 773 and I am considering getting rid of my 753.

It is important to understand that It is not a humming ground loop that is constant but a popping or crackling that appears for a split second then re-occurs every minute or so throughout the night.

I have lost handfulls of hair over this problem as I just finished setting up this new H/T system and paid $4000 for something I can't really enjoy to the fullest.

Any help is greatly appreciated.

Before you use a cable coax isolator, by the way, there is a post just above A/C hum..., who solved his hum problem by a Jensen product, you may want to just disconnect the cable first and see if that solves your problem over time. If not, a cable isolator is of no use.

 

[sjdgpt]

Chasing electrical ghosts

First rule of isolating a noise, is isolating the equipment, and then try to duplicate the noise with another brand of equipment at your location, or this unit at a different location.

If you can not duplicate the noise with this equipment at another location, it is not the equipment.

There is a chance that another brand of equipment would not have the problem at your location. Then again, maybe another brand would have the same problem. Each manufacturer do use different noise suppression circuits within their equipment, but those circuits are for internal problems (tuner noise, feedback between circuits) and common external problems, so I doubt switching brands of equipment would solve the problem. But it is always an option.

You also need to to try the receiver on a different electrical circuit within your house. This does not mean a different receptacle, but an acutal seperate distinct circuit.

My feeling is that because the problem occurs mostly at night, there is a great chance it is not related to the equipment, but the condition of your wiring, or one of the famous sources for noise generation such as the central heat/air unit, especially heating units.

Finding a single piece of electrical equipment that could be generating the noise is going to take a lot of time and investigation.

In the mean time, take the receiver to a friends house and try it on their system. Let's make sure the problem is not the reciever, before we start chasing electrical ghosts.

 

[Redbone]

Yes, that is a great idea I will take it somewhere else though the disconection of all those cables is a major hassle.

With the cable ground loop hum thing is the noise constant? Because it is not constant in my system. Like i said it is intermittent line noise static and a crackle.

I have heard several pieces of electrical equipment that generate noise through the speakers, Refrigerator compressor motor, Dishwasher, heating unit for starters.

 

[Redbone]

I find it interesting that when the noise occurs you can actually see a horizontal static line on the tv screen for a split second. I have never had this happen to me in the past. I don't know what it could be? It just keeps coming up in my head though as a grounding issue- I have read so much about NAD receivers and grounding issues.

 

[markw]

This ain't a grounding issue, dude. It's electrical interference (EMI).

I find it interesting that when the noise occurs you can actually see a horizontal static line on the tv screen for a split second.

And, from your description your TV signal is affected by it too. First thing to find out is where it's coming from. From your description it may be originating from outside your residence and it CAN travel through the ari as well as through the wiring. Good luck....

 

[Redbone]

I disagree Mark, it only occurs when the stereo is on, when it is off no noise or lines come across the TV. Contemplating going to Circuit City and buying a HK435 to demo then returning it. To see if the NAD is the problem.

 

[markw]

Then perhaps the stereo itself is defective and is causing the EMI. Your right in swapping out the stereo. If it persists with the new stereo, well..., then perhaps it's another component that is only powered up when the stereo is on.