Interference noise at USB connection

Portable PA
1

I’ve got interference noise when I plug in my Laptop into the USB-Port of the tonematch. I tried other PC and Laptop and these don’t show this behavior. I am not sure, whether it is the HD or the CPU-fan or anything different.

Is there any noise filter for USB-cables or another workaround? Unfortunately I cannot change the laptop because I dont have any similar - it is mainly the size and the performance of this special type (Dell Latidude D620).

Thanks for your help.

dotzo

2

Hi dotzo,

Thank you for joining the forum.

Does the noise go away if you disconnect the laptop power supply from the laptop?

3

Wow, yes indeed. I just tried - I guess I need to cut of the protective wire?! Unfortunately I cannot run it the wohle night without power supply.

4

Yes indeed it is gone, after plug off the power supply. How can I solve it while plugging in the power supply. Thanks.

dotzo

5

Could be your power supply to your laptop. Do you have the same noise when you run off the laptop battery? If so get the Hum-X.

6

Hi dotzo,

You could get another battery - or an external laptop battery. These can be really handy because you can use them with different laptops if you have the adapters to support them. You could even consider getting a Dell 12 Volt adapter (suitable for use in the car) and run that from battery.

I am NOT going to suggest that you cut-off or defeat the ground connection on your existing power supply. But maybe you can source another power supply from Dell that is correctly wired so that it does not require it.

7

http://www.adorama.com/images/Product/ZZAC32.jpg

Dotzo, people are going to disagree with me on this but I’ve been using this for almost 9 years on the same computer and no problems yet. You can buy these at your local dollar store too. gets rid of the hum instantly.

8


Safety Note

NEVER use a cheater plug or cut the ground plug off an ac power cord.

From the Owners Manual

Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wider blade or third prong is provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.

–?8T? Please click the picture for more details ?T8?–