Buzzing sound with certain laptops - why?

[JLNorthGA]

A tale of several laptops.

My personal laptop (a HP/Compaq) does not buzz, hum or make noises when I plug it into the building sound system. I can leave the brick plugged in and the laptop charging, I can unplug the brick - it doesn't matter. The sound is clean using a 1/8" stereo jack into the headphone socket or using a USB adapter.

The theatre laptop is another story. When it is plugged into the wall and charging - it has a nasty buzz when plugged into the building sound system. I'm plugging into the same receptacle! There is no noise when it is not plugged into the wall. We tried a 2/3 prong adapter and there was no noise - so it is the ground that is somewhat responsible.

The same thing occurs with other laptops - as soon as they start charging - the buzzing noise occurs. Other laptops are similar to mine in that they make no noise when charging.

What is occurring? What is in certain bricks and not others that causes the buzzing noise in the building sound system??

How can it be fixed? I don't really want to use 2 prong/3 prong adapters. Nor do I want to use my laptop for all show which need them.

 

[josh88]

A tale of several laptops.

My personal laptop (a HP/Compaq) does not buzz, hum or make noises when I plug it into the building sound system. I can leave the brick plugged in and the laptop charging, I can unplug the brick - it doesn't matter. The sound is clean using a 1/8" stereo jack into the headphone socket or using a USB adapter.

The theatre laptop is another story. When it is plugged into the wall and charging - it has a nasty buzz when plugged into the building sound system. I'm plugging into the same receptacle! There is no noise when it is not plugged into the wall. We tried a 2/3 prong adapter and there was no noise - so it is the ground that is somewhat responsible.

The same thing occurs with other laptops - as soon as they start charging - the buzzing noise occurs. Other laptops are similar to mine in that they make no noise when charging.

What is occurring? What is in certain bricks and not others that causes the buzzing noise in the building sound system??

How can it be fixed? I don't really want to use 2 prong/3 prong adapters. Nor do I want to use my laptop for all show which need them.

We just had this problem and I know its come up on the forums before. Somebody I'm sure will have the science reason as to what its actually doing. In the case of the laptop that was doing it for us, everything was a few years old, we pinned it down to the power cord, got a new one and it went away. do you have other laptops or chargers floating around? if you don't a new one can be bought pretty cheaply on the internet most likely. our replacement was only a few bucks and it hasn't been an issue since.

 

[JohnD]

Here is a thread at CB:
http://www.controlbooth.com/forums/sound-music-intercom/14523-laptop-sound-noise.html
Here is another thread at soundforums.net:
Noisy laptop power supply

 

[themuzicman]

How can it be fixed? I don't really want to use 2 prong/3 prong adapters. Nor do I want to use my laptop for all show which need them.

Grab a PCDI or a Radial JPC. Made for just this reason.

 

[JLNorthGA]

Grab a PCDI or a Radial JPC. Made for just this reason.

The pcDI looks good. We've had a problem with hooking up the Clavinova. We're currently using a DI box with adapters. This would get rid of the adapters. I don't like the price tag, but I do like Whirlwind.

 

[JohnD]

Another option might be this one:
DBRC-2A
I have no experience with this but most Audiopile.net products get good reviews.

 

[themuzicman]

I have no experience with this but most Audiopile.net products get good reviews.

Do you really want to trust a place that has the word "audiophile" in their name?

 

[DuckJordan]

Actually their products are pretty good, I prefer radial but won't turn down the audiophile stuff, I will not buy whirlwind anymore however.

 

[mstaylor]

I have a PC-DI and it is great. I too can use mine with no problem but the last three presenters laptops I have had to lift with the DI.

Sent from my C771 using Tapatalk 2

 

[museav]

Do you really want to trust a place that has the word "audiophile" in their name?

It's "Audiopile" and they have a very good reputation for providing high value products and great service.

 

[JLNorthGA]

Actually their products are pretty good, I prefer radial but won't turn down the audiophile stuff, I will not buy whirlwind anymore however.

Could you give your reasons for not buying Whirlwind products? I see the Audiopile product is much less expensive - and more in suiting with my budget - so I don't mind purchasing it instead.

 

[DuckJordan]

You pay for the name with that product and from my experience they don't hold up well on tour. Again this is coming from concert industry and not theater but if I'm spending that kind of cash it should last more than a month under the same conditions my audiopile Di puts up with for the last 6 months

 

[hosko]

I use to DJ using a laptop and a firewire sound card, I always had a Behringer HD400 2-Channel Hum Destroyer. Always fixed any problems I had, also coverts unbalanced to balanced which is nice as well.