Solution to destroy hum then connected to PC/Laptop: BehringerHD400

Hi all,

if you have also hum/buzz/crackle noises in your sound System, I found a very easy and cheap
solution to fix it.
I’m ownest: I looked a long while to solve the problem with the interferences.
The noises come, if you connect hardware synthesizer devices with a laptop/PC system and you
use the audio output through/from laptop/PC system.
I always thought, the noises are produced by the internal soundcard. So, I also tested
external “high end” soundcards…same problems.
Then I read/heard, that I have to sort my power supply units and so on and so on.
Nothing of the advices helped.

On the end I found finally, what the problem caused by:
It has to do with different electrical mass/electrical grounding PC/laptop <> synthesizer/connected hardware devices. This causes the noises.
AND…it is very easy and cheap to solve: I bought now a Behringer HD400 hum destroyer for around only
25$. Here you have 2 input and 2 output 6mm audio jacks…so stereo.
And then…problem completly solved! :slight_smile: :slight_smile: no noises/interferences furthermore.

I’m angry, that I found so late a solution :slight_smile:
Before I had always switched/reconnected my audio stuff to my PA system in order to get rid of the noises.


Any transformer coupled DI BOX should do the trick. I have something similar in my Gig Box (also from Behinger, but not this particular one) for the times when a sound man cannot take line inputs and/or you need to connect to a stage box. So it’s well worth having something like this in your gig box.

Whether or not you get this problem can depends on your audio interface as well. Some I have had to transformer couple to remove ground loops (hint you can always check that this is an issue on a laptop by unplugging the power supply. If the problem goes away, you have a ground loop).

From your post, it sounds like you may be using the built in computer audio? That’s not really recommended for serious music applications as they are at best average quality, and usually carry internal noise from the computer itself due to poor shielding.