ProDI

From Radial Engineering:

The ProDI is a passive direct box designed for use on stage or in home recording studios, with the ability to handle high output instruments without distortion, and a transformer-isolated output to eliminate noise from ground loops.

The heart of the ProDI is a custom wound Radial transformer. It features an exceptionally high 140kΩ input impedance to reduce loading while enabling the ProDI to handle extreme signal levels at all frequencies without distortion. This is further improved upon with an internal MuMETAL® shield to protect against electromagnetic fields that can cause unshielded transformers to distort.

The ProDI works great for high output devices like active bass guitars. It's able to handle the huge signal levels from active pickups without distortion and the transformer isolation prevents ground loop hum. The ProDI sends the pure sound of the bass to the PA and to the player's amp.