There is a switch on the DI that allows you to reduce the signal by 20 or 40 decibels. This makes it much easier to mix when using an instrument that is high-Ohm, for example. You can also easily use the DI box as an intermediate step because there is a link-out on the mixer. This allows you to easily send the signal from a guitar to the AR-133 first and then to the guitar amplifier with the link-out.