"Humming" noise when capturing Audio?

[mikehende]

Strangest thing, I am going from the Audio-Out on my TV to the Line-in on my pc but I am getting a background "humming" noise, it is not coming from the TV and it is not the cable I am using so this is coming from the line-in input on my pc in some way, any ideas/fixes please? Also, the Audio when captured plays back with the hum in it.

[dphirschler]

Sounds like a ground loop. Ground the two devices together.


Darryl

[mikehende]

how can I do this "ground" please?

[SLK001]

It IS your cables. A TV is a horrific generator of 60Hz magnetic field "hum" (just try to play an AM radio near the thing). Low frequency magnetic fields are near impossible to sheild cheaply.

Try recording the audio from a VCR audio out.

Or, record the audio, hum and all, then run the audio through a 60Hz notch filter using your audio editing program.

[mikehende]

I have tried 2 different quality cables and also when I run the TV audio through my Home Theatre system using those same cables there is absolutley no hum so I don't understand how the cables can be the problem? The hum is only when I use the line-in of my pc.

[gadgetguy]

Do you have on-board audio or an audio card? If you have an audio card, try it in different slots and see if there's any change.

[mikehende]

no, only the integrated soundcard that came with my Dell desktop, I wonder if any settings in windows volume control panel has to be adjusted?

[mikiem]

Think when you research this and google a bit you'll find a lot of possibilities. Visit Jay Rose's site, check out his writing on-line and in print for a lot of hints.

Basically could be your PC &/or sound chip. Could be ground prob, where you have a voltage between the different grounds. Could be a light dimmer switch, or the type of lighting. Could be your TV.

[wingnut2003]

it's most likely a ground loop issue. you need what is called a ground loop isolator.

[Bjs]

Also , while connecting from vcr may fix problem , check the audio socket on the motherboard has the back plate tab against it , all the connection's that protrude through the backplate have a tab , to earth them correctly .

The mother board when installed may not have been inserted through the back plate correctly , thus it is not earthed correctly .

Or the tab that reside's against the audio connection's can be broken , missing in action ... in this case , you will need to remove the motherboard , remove the backplate , and solder on a new tab for it ... get this from an old junked pc ...

Getting hold of replacement back plate's for a specific motherboard is almost impossible ... there a part no one has on hand , because it is considered an unusual request .

[mikehende]

Finally found the problem guys, the hum is coming from the Cable Equipment, notably from the cable line that's coming in from the Dish on the Roof, they will be sending someone out to fix it next Monday, appreciate the responses, take it easy.