Helix LT Hum issues

[Ziptor]

Greeting everyone! First time poster with a problem that I have been troubleshooting to not much avail.

I have been using my LT with the guitar/bass straight in, and using USB to Reaper and Headphones out for my outputs. Whenever I have an instrument plugged in, I get an additional hum over just the amp noises, even when running clean. The hum usually reduces, but does not entirely go away, when my skin is in contact with the strings or bridges of my instruments. I have tried different cables, different guitars, and unplugging the USB from my LT, but to no avail. Does anyone know what could be the cause of this, and how to abate it? Thanks.

[cheekybeermonk]

It could be a number of things, if you are using an extension cable to plug into the wall socket for power is that earthed ? Could you try plugging in to a different wall socket somewhere else in your home ? Do you have led or halogen lights with transformers, if you switch them off does the hum go away ?

 

if I forget to plug in my MacBook while USB connected to my LT I do get a lot of hum , try plugging the computer and LT into the same wall socket ?

[Ziptor]

Thanks for the help, the hum is there regardless of if the unit is plugged into the USB or not. The USB hum issue is MUCH worse when I was running 4CM with everything plugged into random outlets. In this case, the pedalboard and PC and plugged into the same outlet, and even when I try other outlets, it remains. I'll check the lights, but I mostly have incandescent bulbs.

[cheekybeermonk]

Did you try the noise gate in the input ? This can really help with hi gain amp models 

[rd2rk]

Are you using a quality power strip/surge suppressor with emi/rmi filters? Is everything in any way connected to the Helix plugged into the same power strip? Have you tested the wall outlet for proper grounding? Do you live on a known ley line?

[mlimbolimbo]

Try a different instrument. This sounds like a grounding issue with the instrument itself. Also, at least temporarily try a ground lift plug on your power cable. Regardless of the DANGER labels, every audio engineer knows that you can't have everything grounded with a third pin and not get noise.

Best of luck.

 

[Ziptor]

Sorry to necro, but last night I did some troubleshooting after the hum turned into a wild screech, that not even the default gate could always filter out. It seems that it is not coming from the monitors, but the tower of my PC itself. Since I am using my Helix as my audio interface, this is a problem. Again, unplugging the USB did not have any effect. Is this a problem anyone has seen and/or solved before? Thanks for all the help so far!

[rd2rk]

24 minutes ago, Ziptor said:

It seems that it is not coming from the monitors, but the tower of my PC itself.

 

If the noise is coming from your PC ITSELF, with Helix NOT connected via USB, how could the problem be the Helix? Are the speakers connected to Helix, or are you using the PC sound card for the speakers? If your speakers are connected to the PC, disconnect them and connect them to your Helix.

[Ziptor]

Sorry, that was confusing. Let me clarify, the EM that is creating the noise is coming from the computer. When I move my guitar away from the interference, the noise drops pretty much to expected background levels. The Helix is being used as the soundcard with headphones into the headphone out, and the hum only happens on the guitar channel, not from audio from the computer.