Direct boxes are the sound engineers’ Swiss Army knife! Here are some examples:
Problem: You need to connect an amplifier’s speaker output to the mic input on a mixer.
Solution: Connect a Phantom I between the speaker output and a mic input with phantom power on the mixer, then set the attenuation switch to –40dB.
Problem: Your PA is humming because there is a ground loop between a signal source and the mixer.
Solution: Connect a Phantom I between the signal source and a mic input with phantom power and set the ground switch to Lift.
Problem: You need to connect an unbalanced line-level source (ie: a synthesizer, another mixer, an effects device, etc.) to a mic input on the mixer.
Solution: Connect a Phantom I between the source and a mic input with phantom power and set the Attenuator switch to –20dB.