Hey there, yup it is indeed a Red Panda mixer (mono 3 into 1). I do also play Fretless when the set warrants it, so having the 3rd input comes in handy. Separate volume for each channel and hi fi quality circuit inside so no volume or sonic issues at all (the mixer is powered so hence no volume drops etc.
I have used a Boss LS2 using the channel A+B option (need a dummy plug in the input) and there are separate volume controls for each channel then also.
I prefer having the instruments live all the time, as I can switch between bass and key bass mid song (verse chorus etc) when it’s suitable without having to step on
anything!