How Can I Eliminate Humming Sound?

[GwenButler]

I have a Ruggedized Laptop™ Computer With Video Hoster® Software and have finally identified my power adapter as the source for the humming sound that is, always present, more noticeable when music stops.
When I unplug my power adapter from my PC the noise stops immediately.

Any advice/suggestions greatly appreciated.

GB

[ddouglass]

Actually it is not the power adapter but the power source (Electrical Outlet). You problem is a floating ground. As a temporary fix get a 3 prong to 2 prong adapter. That eliminates the hum from the ground. This not the best way to fix this but it is a quick way to prevent it.
If this is at a club you are playing at see if they can get the plugs fixed in the stage area or Radio Shack sells a device to protect against this problem (someone else will have to tell you what it is called....I don't remember).

[Lonman]

Actually a REALLY safe way to eliminate the ground hum without actually eliminating it is the ebtech.com hum eliminator. No losing ground wire sources.

[billyo]

you can get a hum elliminator from radio shack for $15.00 dollars, or the one from ebtech for $60.00, i have both of them, a found that the one from radio schack is easier to work with, just plug your laptop cable to it and them plug the hum elliminator to the power source, and also ebtech sells a hum elliminator for your mixing board too, they have 1 or 2 channels..you can choose from.

[ddouglass]

Originally Posted by billyo

you can get a hum elliminator from radio shack for $15.00 dollars, or the one from ebtech for $60.00, i have both of them, a found that the one from radio schack is easier to work with, just plug your laptop cable to it and them plug the hum elliminator to the power source, and also ebtech sells a hum elliminator for your mixing board too, they have 1 or 2 channels..you can choose from.

Billy do you know what the item from Radio Shack is actually called? Searching for a hum eliminator doesn't come up with anything.

[GwenButler]

Your timely responses greatly appreciated!

GB

[billyo]

Originally Posted by ddouglass

Billy do you know what the item from Radio Shack is actually called? Searching for a hum eliminator doesn't come up with anything.

i think its actually called ground noise supressor

[muzicman144]

Originally Posted by ddouglass

Actually it is not the power adapter but the power source (Electrical Outlet). You problem is a floating ground. As a temporary fix get a 3 prong to 2 prong adapter. That eliminates the hum from the ground. This not the best way to fix this but it is a quick way to prevent it.
If this is at a club you are playing at see if they can get the plugs fixed in the stage area or Radio Shack sells a device to protect against this problem (someone else will have to tell you what it is called....I don't remember).

It is called a ground loop isolator, about $16.00 Radio Shack. Humtech does the same at about $50.00
muzicman

[ddouglass]

Gwen, are you getting the hum when it is just the laptop (internal speakers) or are you getting it when you have the laptop plugged into your sound system (mixer, amp etc)?
And the Radio Shack item is called a Ground Loop Isolator. I finally found it on there website. Those will help when plugged into your sound system.
Another thing that can help is to make sure all your system items including the laptop are plugged into the same circuit.

[captnkarl]

I had the same problem and the answer I got was "get a 3prong to 2 prong thingy"...That worked great and have used it since. If you unplug your power supply to the laptop, that will eliminate it also (battery won't last for a whole show). I doubt that it is the club because I had it at every club and in my house and I know that everything is grounded right in the house because I wired it myself. Dell told me that unless lightning strikes the club I will be fine running the way I do now.

[madjim- with the Lord]

Originally Posted by captnkarl

I had the same problem and the answer I got was "get a 3prong to 2 prong thingy"...That worked great and have used it since.

Karl,
I know using the 3 to 2 prong adapter lifts the ground and works but eliminating your ground completely puts your gear in danger. They are good for a quick fix or to locate a hum/buzz but the Ground Loop Isolator is the cheapest SAFE way to get rid of the hum that I know of.

Just trying to help.

Jim

[ddouglass]

Originally Posted by captnkarl

I had the same problem and the answer I got was "get a 3prong to 2 prong thingy"...That worked great and have used it since. If you unplug your power supply to the laptop, that will eliminate it also (battery won't last for a whole show). I doubt that it is the club because I had it at every club and in my house and I know that everything is grounded right in the house because I wired it myself. Dell told me that unless lightning strikes the club I will be fine running the way I do now.

So do you shut down the show if there is lightning in the area? Did Dell also tell you that your warranty will not cover that damage?
Just because it does it at every club does not mena that it still isn't their ground setup. Lowes, Home Depot, etc. all sell a simple small 3 prong tester that will tell you if their outlets are correctly wired.
Another thing that can cause this is if all of your equipment is not on the same circuit in the building. Such as using powered speakers spred out across the room. If the circuits are not all grounded to the same buss bar in the panel there is a potential for a difference in the two separate grounds which will read as a voltage across them.
When you go to strictly battery on the laptop you now are using straight DC voltage with no AC voltage present. AC voltage in this country uses a 60HZ (cycles per minute) sine wave signal to carry the voltage to whatever item is plugged in. The sine wave signal is what causes the hum.

[Lonman]

Originally Posted by captnkarl

I had the same problem and the answer I got was "get a 3prong to 2 prong thingy"...That worked great and have used it since. If you unplug your power supply to the laptop, that will eliminate it also (battery won't last for a whole show). I doubt that it is the club because I had it at every club and in my house and I know that everything is grounded right in the house because I wired it myself. Dell told me that unless lightning strikes the club I will be fine running the way I do now.

Yes they work, but is also dangerous, I could care less about the equipment, but to the human that is operating it. Something spikes & there is no ground prong /wire to default to, it could shoot back through your system & straight to the person holding the mic - they are now the ground. And if it doesn't kill them, they are going to suing the person who removed that ground prong while they are recovering.
Just something to think about, doesn't happen often, but yes it can & does happen, do you really want to risk it?
There are plenty of SAFE ways to remove a ground, sure they cost a bit more, but will keep the ground completely intact while completely eliminating the hum!

[madjim- with the Lord]

Originally Posted by Lonman

I could care less about the equipment, but to the human that is operating it.

I was thinking this but it didn't come out in my post, moving too fast again. Thanks for the back up Lonnie. The "Fear Of Frying" is something we should allways keep in mind.

Jim

[marklwood]

I would like to add to Lonmans explanation. In my experience, the weakest link in a bar situation is all the neon transformers. They are not like most usual electrical equipment in other situations. The transformers in these normally carry 100,000 volts or more and are prone to premature failure. They can fail gracefully or quite spectacularly taking all that is electrically connected (including anyone acting as a ground) with them. While there is not much amperage, it can, and has caused death. This is typical voltage of a taser. While not normally fatal, read the news. How many deaths by taser have we read about lately.

[Eric Whitehouse]

My singers are getting used to performing under these conditions, since I purchased my 5' long cattle prodder.

No seriously the ground loop isolator is the safest cheapest option I know of.
Don't risk removing the earth

[GwenButler]

I am unable to post anything--please help! I am having the following problem:


I have a Ruggedized Laptop™ Computer With Video Hoster® Software, and just had my first paying gig. (Thanks again to everyone who helped out by answering my many pre-gig questions!) At the onset of the gig I had a MAJOR humming sound problem that seemed to be caused by my brand-new amplifier (Crown XLS 202 DJ XLS202Dw/200 watts in each channel at 8 ohms).

My Crown amp was working perfectly fine when it was at my home, however, after being transported less than 5 miles away a horrible humming sound kicked in. . After quite a bit of troubleshooting (component to component wires, speakers wires, laptop wires, etc.) I gave up. Luckily a spare amp was available. After replacing the Crown AMP with a (over 20 year old) Audionic of Oregon CC-2 APM (117 VAC 60 HZ 4 AMP Bridge Mono CHA 80 OHM MIN) the problem went away, however, the output sound was no where as good as when I was home. After the gig I went home to engage the Crown AMP and everything worked perfectly.

Just wondering if the establishment’s power source could have been the problem as the performance took place in a newly added building addition that had numerous Keno machines, flat screen TVs mounted on the walls and a juke box.

Any and all advice greatly appreciated.

Gwen

[marklwood]

Originally Posted by GwenButler

Just wondering if the establishment’s power source could have been the problem as the performance took place in a newly added building addition that had numerous Keno machines, flat screen TVs mounted on the walls and a juke box.

Any and all advice greatly appreciated.

Gwen

I can almost guarantee it.
There is a problem with the ground. The ground, just like water, takes the path of least resistance. If your amp is closer, it will act as the ground. The older amp just may be a little more tolerant of the problem. Geat a ground loop isolator. They are cheap enough at Radio Shack to be a no-brainer.

[GwenButler]

Thanks for all the advice/support!

GB