front panel input impedence

[Sylv1co]

Hi,
does anyone know the impedence of the front panel instrument jack input on Receptor 2pro ? The manual says that we can plug a mic (with jack?!), a guitar, or an "instrument" (keyboard ?), but there are usualy 3 different types of plug : line (for synth for exemple), mic (for mic!), or HiZ (for passive guitare pickup). How Receptor can accept all type of instrument into the same input ?