With a Direct Box, you can directly take a sound signal from a highly resistance cable, e.g. between guitar and amplifier, change the impedance, lift the ground, attenuate the signal and send it to the mixer inputs.
With a Direct Box, you can directly take a sound signal from a highly resistance cable, e.g. between guitar and amplifier, change the impedance, lift the ground, attenuate the signal and send it to the mixer inputs.