I’m opening this topic which is not directly linked to Mixxx but, I think this is the best place where I could find some help advices for my problem.
My configuration is the following
- Screen, mouse and keyboard connected to a Targus «Display Link» dock171
- My personal laptop (a DELL Latitude 3350) using the «Display Link» tips to get the power supply
- A sound amplifier (an antic Pioneer SA-506) on which I connect my speakers and my headphone. The sound amplifier can be connected either to the laptop jack output or to the «DisplayLink» jack output.
My problem is this one : I got a general background noise louder enough to be clearly heard in my headphone or the speakers, even at low level. Over the background noise itself, I can hear a kind of regular «beat». All of those parasites are slightly louder either each time I’m moving my mouse or use the trackpad of my laptop or when I’m typing on the keyboard.
But this background noise is disappearing in the following cases
- If I’m disconnecting the power supply / use the original power supply of my laptop when I’m using the laptop jack output (but, I’m upset to get many power supply everywhere around my desk…)
- If I’m disconnecting the laptop jack output (and use instead the DisplayLink jack output) when I’m connected with the DisplayLink power supply
- it is almost disappearing if I insert an «adapter» to bypass the mass between the socket and the DisplayLink power supply. But I always thought the mass was done to protect my equipment…
So, I can’t determine if the problem is coming from the DisplayLink power supply or from my jack / RCA cables or anything else.
I tried with another sound amplifier : same problem.
I tried with other jack / RCA cables : same problem
I tried with another laptop (a DELL too) : same problem
I tried to connect many different power supply (Tips of the DisplayLink, a power supply of some other DELL, and the initial DELL power supply) : the background noise almost disappear with the «original power supply, and have various level with the other power supplies.
Does some of you already experimented such problems ? And how did they solved it ? I heard those background noises are usually pain in the ass, so, thank you for the ones who will accept to spend time to try to help me.