Stereo Aux Input Question

Hello…newbie here. I’d like to run my Roland FA-08 keyboard into the Aeros. The FA-08 has two mono (L/R) outputs, headphone stereo output, and an AUX line level output that can send a stereo signal. I want to use the stereo AUX input on the Aeros for the keyboard. From the keyboard, should I use the stereo AUX line level output or the stereo headphone output? Thanks

The above link may have helpful posts.

I would say either will work, try both out and sere which one seems to feed the healthiest signal into the Aeros