Ground Loop Buzz when Powered Off Problem. What are possible Solutions?

Quad Cortex
1

I just received my Quad Cortex and am a little concerned about the seemingly well known Ground Loop Problem. I connect it via XLR and whenever I turn it off I get a constant Buzz sound, as long as I don’t disconnect the Power. When it’s on, there’s no such problem.

I saw several Posts regarding this problem but no clear solution. One thing that was suggested is to go to standby befor turning the qc off, because in standby it disables the outputs.
But how do I turn it off from standby without leaving standby and turning the outputs on again?

Or are there any workarounds that solve this problem, beside unplugging the cables?

Thanks in advance for your answers!

2

The solution is to turn off whatever amplifier / monitor / speaker system you’re using, then the QC. Same as any other piece of audio equipment.

3 Likes
4

This isn’t a solution. So I can’t have my monitors on when I have the QC off? I need them many times without the qc, but I get a permanent buzz. There have to be a workaround or else there is a major bug.

5

Sorry. The workaround is to disconnect your QC when your monitors are on.

Perhaps you can control it by running your QC outputs into a mixer, then running the mixer output to your monitors. Then all you would have to do is turn the QC channels (assuming stereo) down on the mixer when you want to power it off. Same goes for any other audio source.

Either way, the point is to disrupt the audio connection to your monitors. Things get weird when there’s no power applied. It’s not a bug.

2 Likes
6

The Loop Buzz happens to me unfortunately always in my studio, none of the replies apply to your question as you already know and the truth is that this should NOT be happening.
It doesn’t matter in what order you turn off your gear (its not about a pop when you turn off a device before turning off the amp/speakers), its about a constant buzz like there is no ground, unfortunately there is NO solution, when you go on standby, you can’t turn it off after that - and there is no workaround… I have a mute in my case and I just mute the QC, but its annoying…

7

the solution is to use unpainted metal xlr connectors

1 Like
8

My solution is to use outputs 3/4 instead, as these don’t produce the dreaded hum. Use TRS (stereo) jacks.

9

I just wanted to share my solution:
I connected my QC via USB to my PC and the hum stopped immediately. The USB Cable seems to ground the QC and therefore eliminates the buzz noise completely. Same happened when I connected additional TRA cables to the Outputs 3/4.
Since I’m only using my QC at home and it’s permanently connected to my pc anyway this solves my problem. Maybe this will help someone.

1 Like
10

I had the same issue, my problem was solved when I replace the shoddy QC power supply.

11

With what power supply did you replace it?

12

Cioks Crux. problem solved.