Roland GO:MIXER PRO-X Audio Mixer for Smartphones - Manual (Page 14)

Connecting a Guitar or Bass
GUITAR/BASS *4, 5
INSTRUMENT
(L/MONO, R) *4
(*4) If you’re routing your guitar (or bass) through an effect
device, connect it to the INSTRUMENT jacks.
(*5) When connecting a guitar or bass with an active pickup,
use the [PAD GUITAR/BASS] switch to reduce the input
signal to lower the amount of distortion.
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