keenness of mental perception and understanding; discernment; penetration. 

[pur-spi-kas-i-tee]

IEC 61938

This is a slightly smarter DI, Phantom powered (so on older consoles that could be an issue, but most modern ones should be fine) so doesn't need a battery.
Transformer output, so it doesn't need an earth lift switch,
Jfet input so very high input impedance,
Low noise, high headroom so unless you are doing something unusual (such as driving it from a power amp) doesn't need a pad,
smart switching on the input sockets either jack can input or thru, it doesn't matter,

The only control is the summing switch (if you want that option, I can make them without) which adds a resistive mixer between the jack sockets.