Buzzing/hissing sound throughout capture.

[Leanoric]

Ive just captured a 6 hour tape of a tv recording and theres a buzzing sound through the whole of it. Does anyone know what could be the cause of this? Its present from start to finish through different shows and films. Can it be removed in post processing?

[themaster1]

Probably a Ground loop (i can see a faint bar in the middle on your capture, that's what strucked me at first glance)
The question is: was it recorded like that on the tape, to begin with.

https://www.avartifactatlas.com/artifacts/ac_beat.html

https://www.sct.com.tw/articles/4-effective-approaches-that-eliminate-ground-loop-vide...o-interference

[Leanoric]

Probably a Ground loop (i can see a faint bar in the middle on your capture, that's what strucked me at first glance)
The question is: was it recorded like that on the tape, to begin with.

The only difference between this capture and previous captures is that my pc is now up on the desk, right next to the vcr, dvd recorder and monitor. I wonder if this has caused some interference? Ill recapture part of the tape with the vcr and dvd recorder down on the floor well away from the pc and monitor. If its the same outcome, then I suppose it was recorded like that.

[Leanoric]

Should input volume be adjusted with each capture? Its not something Ive given any thought to before but Ive just read that when its reduced it can eliminate the buzzing noise that is present on some vhs captures.

[themaster1]

Just connect all the devices to the same power outlet. Try to keep away electric cable from video/audio ones. Use shielded cables and rubber on devices's feet.

If all the above fails i guess you can be on the hunt for a GL isolator. Just type "ground loop audio isolator" on amazon