Active Di Box Vs Passive

The most basic definitions of the two different kinds of di boxes are likely what you d expect.

Active di box vs passive.

The most obvious difference is that passive di boxes don t need to be powered. For an in depth look at choosing active or passive direct boxes please check out the free guide on our blog. Active versus passive di box the di box for direct injection or direct input also known as a direct box is a device who s main basic function is to convert the unbalanced high impedance output of an instrument s signal into a balanced low impedance one which in turn allows longer cable runs without adding noise among other benefits. But the differences go deeper than that.

Active di boxes require a power source usually batteries or phantom power over an xlr jack. The biggest difference between an active di and a passive di is that an active di includes a preamplifier. They contain a transformer to perform impedance matching and balancing and very little else the strength and impedance of. A passive di unit typically consists of an audio transformer used as a balun.

Passive di boxes are basically just transformers. Passive does not have active electronics and therefore does not require an external power source. Typical turns ratio is about 500 1 to match a nominal 50 kω signal source such as the magnetic pickup of an electric guitar to a 100 ω input.