Noise w/ FC-6 + EV1 (Volume + Expression)

[AegisOfPaean]

Hi All,

tracked down a noise issue in my setup to FC-6 + EV1 if I use the EV1 as expression and volume (guitar in, out to AxeFX-III) simultaneously. The noise is an airy ~700hz, with sporadic clicks I associate with data transmission. Can listen to the initialization sequence by unplugging the XRL and plugging it back in; not recommended with any sort of volume.

This setup is an experiment. I'm guessing the solution is "don't do that", but I'm curious what causes the noise, why it's an airy ~700hz, and if there's a solution.

Regards, from a newbs first post.

 

[unix-guy]

Hi All,

tracked down a noise issue in my setup to FC-6 + EV1 if I use the EV1 as expression and volume (guitar in, out to AxeFX-III) simultaneously. The noise is an airy ~700hz, with sporadic clicks I associate with data transmission. Can listen to the initialization sequence by unplugging the XRL and plugging it back in; not recommended with any sort of volume.

This setup is an experiment. I'm guessing the solution is "don't do that", but I'm curious what causes the noise, why it's an airy ~700hz, and if there's a solution.

Regards, from a newbs first post.

I believe the manual for the EV-1 states specifically not to do that...

Edit:

It does. See attached.

 

[AegisOfPaean]

Awesome, thank you! I see "Do NOT use Expression and Volume functions at the same time or ground loops can occur. "

 

[FractalAudio]

Yeah, don't do that.

 

[AegisOfPaean]

Decided to pop the cover. The potentiometer is shared across expression and volume circuits. Add a potentiometer, separate circuits, isolate gear, and ground loop could be solved. Curiosity fulfilled.