Capture buzzing - is my device screwed?

I have my quad cortex plugged into the same outlet as my two Yamaha stereo monitors. Because it’s connected to XLR I believe it’s grounded properly?… if I add a neural capture like the drywood purple I get an insane over the top buzz! Does anyone else have the same issue?

Hey! Just had a read and seems that the quad cortex should be grounded using the XLRs to your monitors.

I’ve found this thread from a few years ago of someone having a similar issue - may be worth looking to see if you have a ground lift switch to try as that’s quite common.

Do you have any alternative power supplies too? I know I’ve experienced grounding issues when using headphones exclusively with original power supply but using a Walrus Audio Canvas HP sorted it.

Unfortunately ground switches don’t work for me. They actually make it worse. I just took my QC to the store where I bought my it to test there. Def still noisy when i enable the capture block but not nearly as electrical / abrasive sounding. I just need to know it the noise level for those higher gain captures are expected behaviour or not.

This is wild. What is plugged into Input 1 on the QC? Also, how are your Yamaha monitors powered?

Just my guitar on input 1. My Yamaha speakers are powered by plugging in direct to my wall outlets I tested these outlets with an outlet tester and they all passed!

It looks very much like a malfunction in one of the switching cables.

What is a switching cable?

I observed a similar behavior when one of the cables connecting the processor (not the QC) to the AC had a poor connection at the XLR cable connector. And of course, even with high gain, this behavior is not normal. Can you tell me if this noise also appears when you connect a regular Hi Gain amplifier?

Wow. Yeah that’s not right. Is there a way you can plug the QC into a totally different wall outlet from the monitors?

also do your monitors sound noisy if there hooked up to anything else?

I have some noisy power in my house and a furman power condition helped. But it was no where close to that bad

I am trying tonnes of combinations at my place but it’s all pretty bad. From what I am reading, the QC AND the Monitors should be on the same power source if possible (like same outlet or same power bar).

As an example, I plugged in a ToneX One pedal last night to these same monitors (same location) (only powered via USB connected to my computer) it was also very noisy/shrieky. I wouldn’t’ say it was as bad as the QC, but it was pretty bad.

If you’re getting noise with both the QC and a Tonex pedal, then there’s got to be something going on with either your monitors, your cables, or the electricity in the room. Isolate everything and test one by one:

  • Swap your cables with a different set if you can
  • If you can afford it, try a good filtered isolated-output power conditioner like a Furman; plug your monitors into that to see if it solves the issue
  • Take your monitors and setup to a different house or building to see if there’s a difference in noise
  • If you’ve got a buddy with a set of monitors at home, ask to plug your QC into their monitors to see if you still get noise; if you’ve got access to a sound system anywhere, try your QC with that.

…and so on. Hopefully a set of tests like these will help you find the problem.

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What about with a pair of headphones using the headphone out? Does it still sound that bad? Or just when you go out to monitors?

Hi! I recently was making captures and having also a lot of noise. But we plug this radial bigshot box between the amp or pedal and the capture out and tested the combinations and always found some that make disapear the noise.

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I had exactly the same problem. I sent my Quad Cortex to the company for repair. Since I had just bought it, I was able to use the warranty, and in the end the issue was fixed.

Can you explain more what the original issue was and what the solution (and time for repair) was from NDSP?

There was a significant amount of noise on the XLR outputs, which became very noticeable at higher volume levels. The issue only affected the XLR outputs. In addition, the unit would occasionally reset whenever the USB cable or even the power cable was moved slightly. It seemed like a grounding issue, but it wasn’t caused by a loose or disconnected cable. At first, I was told the repair would take four to six weeks, but it ended up taking a little over six weeks before they returned my Quad Cortex. The problem has now been completely resolved—there is no noise on the XLR outputs anymore, and the random reboot issue has also been fixed entirely.