Do I Need A Direct Box? Yep

Since guitarists use amps, and so do many keyboard players, you might overlook the need for a direct box. But a direct box is a tool along the lines of cables, pics, sustain pedals, and tuners – an essential accessory.

If you don’t have one in your toolkit, you should probably find one. If you don’t know what a direct box is, we’ll talk about that first.

What Is A Direct Box?

A direct box, or DI (“direct inject”), is a very basic tool. A DI converts a high-impedance, unbalanced signal (such as that of a guitar, bass, or keyboard output) to a low-impedance, balanced signal. There are two basic times this becomes necessary

• Long runs - if you’ve got a long cable run, a DI will help prevent a loss of volume and high frequency information.
• Mic input – A DI allows you to plug a guitar, bass, or keyboard directly into the mic pre of a console.

The later situation is most likely, as many venues have no other way to inputting to the house sound system (usually via an XLR snake on the stage). If you’re running a guitar or bass amp, you won’t usually need a DI, but you may find yourself in a situation where one would come in handy.

For example, if your amp goes kaput 3 minutes before show time, a DI will allow you to patch directly to the house sound system (even if you use pedals). You may lose your favorite amp’s tone, but you haven’t lost the gig. Plus, the engineer will probably be glad, since you’ve just eliminated a major source of added stage volume and allowed greater control over the mix.

The same is true for the bass, and in some situations, the house sound engineer may prefer you patch directly to the system rather than using your amp. You may not love the sound of that now, but having the option is wise.

Even if your amp is fine and the house has no issues with it, a direct box with a thru/bypass will give you the option of sending both to your amp and the house – which gives everyone the most flexibility. A DI like this will almost certainly be used in the studio to capture both the amped and direct signals.

For keyboard players, having a direct box (or two – or a multi-channel box - if you intend to send a stereo signal) in your kit is essential. You may think that the venue will have direct boxes, but many do not. Best to carry them, lest you find yourself cut out of the show entirely.

Finally, a direct box is a necessity if you plan to use an acoustic guitar on stage – unless of course it has no pickup. House engineers won’t thank you for not giving them a direct inject option, as miking an acoustic on stage can be a feedback nightmare in some rooms.

Passive or Active?

DIs come in two basic flavors: passive and active. Passive DIs do not require power. They’re inexpensive, durable, and ideal for instruments with strong outputs. Carvin Audio’s FDR60 Direct Box is a good example of a stage ready, durable box with a ground lift switch, attenuator, and dual output, so you can send your signal both to your amp and to the house. In most cases, a box like the FDR60 will be all you need.

Active DIs include a preamp, which can provide an extra boost to weaker output sources such as single-coil pickups or help drive those long cable runs. Active DIs require power and are generally more expensive, but they sometimes provide advanced signal routing and higher headroom, making them great for keyboards. Power for active DIs can come from any number of sources, depending on the model, including AC power supplies, batteries, and even phantom power.

Also in Guitar / Bass Amplifier Info & Education