Help! loud noise when using XLR outs and ground lift enabled.

[Ace5150]

Hi all,

I've just purchased a used AX8 and been playing around with it when a USB cable was ALWAYS connected to the computer (Ax8-Edit was always on) and connecting from the two XLR outs of the AX8 to my preamp then computer.

When I unplugged the USB cable, A loud, constant, interference-like noise started immediately and never stopped until I toggled the XLR Ground Lift switch back to off (I didn't even pay attention to what state it was to begin with, because I never heard any noise until today, but I don't think I ever played without the USB connected to my computer either).

With the ground lift in OFF position - everything sounds fine, but what if I need to use the ground lift and I get that noise again? is that normal? any workarounds perhaps?

Thanks for reading and for the help!

 

[pauly]

Hi Ace,
Perhaps the new cable is different to the old one. Have you tried switching back to see if the old cable is fine? If so, the culprit may simply be the new cable, and it may not be worth worrying about.

Thanks
Pauly

 

[Ace5150]

Hi Ace,
Perhaps the new cable is different to the old one. Have you tried switching back to see if the old cable is fine? If so, the culprit may simply be the new cable, and it may not be worth worrying about.

Thanks
Pauly

Hey Pauly and thanks for the reply!

There are no new/old cables - the setup is exactly the same... 2 XLR cables to my preamp, 1 usb cable (for data / ax8-edit).
I tested the xlr cables with microhphones, same inputs on the preamp - no noise.

Again - the problem only happens when I turn on "Ground Lift" and the usb cable isn't connected to the AX8. some sort of digital noise happens then. I guess I only found out today, because I never played without the usb cable connected to the computer until now.

 

[unix-guy]

Is your computer on a different power circuit that your AX8?

It sounds like maybe the USB cable is creating a ground where it's maybe missing without it... Turning ground lift on is also addressing that issue, I think.

 

[Ace5150]

Is your computer on a different power circuit that your AX8?

It sounds like maybe the USB cable is creating a ground where it's maybe missing without it... Turning ground lift on is also addressing that issue, I think.

no, same power strip.
Anyway I just got home from a gig where I went straight to the P.A from the XLR outs and everything sounded fine...
I didn't even bother to check the ground lift position (nor did I have enough time)