Bad hum when AX8 is connected to USB

Mitch Lavin

Member
Hey,
Just purchased an AX8 to compliment my XL+ in my teaching studio. When I plug the unit into the USB with a shielded USB cable I get a pretty noticible hum thru the Atomic CLR monitor. Dead quiet when not plugged in. It's rather annoying when I'm using Edit or Fractool. Does anyone else have this problem? Do I need a USB Isolator? No issues with the XL+. Stays plugged in to the iMac continuously.
Thanks!
Mitch
 
Hey,
Just purchased an AX8 to compliment my XL+ in my teaching studio. When I plug the unit into the USB with a shielded USB cable I get a pretty noticible hum thru the Atomic CLR monitor. Dead quiet when not plugged in. It's rather annoying when I'm using Edit or Fractool. Does anyone else have this problem? Do I need a USB Isolator? No issues with the XL+. Stays plugged in to the iMac continuously.
Thanks!
Mitch

I have the same issue on my 2010 iMac and get around it by unplugging the USB when recording. Some iMacs generations are notorious for poor USB and FireWire grounding issues. Let me know if the isolator works.

The problem doesn't exist when I use my 2015 MacBook Pro.
 
Yup, I take the cable out when I'm not updating patches but I prefer to have it plugged in. I'll try an isolator and let you know.
Mitch
 
Can be a ground loop.
First, test if this happens if you remove the laptop from the charger and run it on battery.

If so, a simple solution is this:
Furman SS6B 6 Plug Surge Protector
Amazon product ASIN B0002D017M
Plug everything to this guy (ax8, frfrs, laptop, etc) so everything shares the same ground.
 
Can be a ground loop.
First, test if this happens if you remove the laptop from the charger and run it on battery.

If so, a simple solution is this:
Furman SS6B 6 Plug Surge Protector
Amazon product ASIN B0002D017M
Plug everything to this guy (ax8, frfrs, laptop, etc) so everything shares the same ground.

+1 to this. It's almost certainly a ground loop that's causing your humming and buzzing.

Technical background info on ground loop problems in audio systems is here.

You can try lifting the audio signal ground at either the Axe-Fx end or at your computer interface's end. If you're using an XLR cable connection, you can try a direct box. The Fractal "Hum-Buster" cables can work for 1/4" connections. More info on humbuster cables at the Axe-Fx Wiki.

Ground loop problems are frustrating, but they CAN be defeated with know-how. :)
 
There are optically isolated usb hubs out there that may help. I actually have one that I used with an old variax guitar when I'd edit the patches through the usb dongle. Worked really well. They aren't cheap though.
 
I'm using CLR Neo II powered FRFR with the AX8. The Axe-Fx goes thru my Neumann studio monitors.

OK, suggestions:

1) Free - try to lift the ground on the AX8. There is a switch in the back just for that;
2) Cheap: Furman SS6B 6 Plug Surge Protector
Amazon product ASIN B0002D017M3) Less cheap: Furman M-8X2 Merit Series 8 Outlet Power Conditioner and Surge Protector
Amazon product ASIN B003BQ91Y6
Both options work, but the M-8x2 is far better. Plug EVERYTHING (CLR, AX8 and iMac) on the SAME power conditioner.
 
FYI, I also have a USB ground loop issue and, and I own both of those Furmans mentioned. They haven't solved any ground loop issues for me. Sturdy build, though.
 
FYI, I also have a USB ground loop issue and, and I own both of those Furmans mentioned. They haven't solved any ground loop issues for me. Sturdy build, though.

Yes, ground loop is a mystery sometimes. For me it solved with my iMac, AX8 and two RockIt 5 monitors. But you never know...
 
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