Awful hum when connecting Mic -> Preamp> Axe-FX III USB

[james...]

I'm trying to take my condenser mic, run it into a Pre 73 preamp, and then run that into my Axe-fx III to record via USB in Studio One.

No matter what input I use, there's an awful hum on the Axe-FX III. I can't get it out. tried a lot of stuff. Nothing works.

Ideas?

 

[blaggers]

I'm trying to take my condenser mic, run it into a Pre 73 preamp, and then run that into my Axe-fx III to record via USB in Studio One.

No matter what input I use, there's an awful hum on the Axe-FX III. I can't get it out. tried a lot of stuff. Nothing works.

Ideas?

Earth loop? Does the mic pre have an earth lift switch?

 

[james...]

It happens even with the preamp is off.

 

[chris]

is there a ground lift switch on the preamp and did you try it?

 

[james...]

There is not.

 

[trixdropd]

Are both plugged into same power circuit?

 

[trixdropd]

If you unplug the pre and the hum goes away then you’ll need an ebtech humx