Do You Really Need A Di Box? Options

[Todd Simpson]

The age old question. Do I really need a D.I. Box? Well, maybe. First let’s talk about what a DI box is. A DI (Direct) Box is a device that converts a high impedance instrument level signal to a low impedance microphone level signal and “balances” the signal in the process. So how and when does one use a DI Box?

One of the most common ways to use a DI box is to connect an instrument (guitar/bass) to the box and then come out of it. You might want to connect out of the box to go to your amp, a mixer, a computer, etc. Your guitar pickups output a higher level signal than a typical mic preamp wants to see. So the Di box can make the signal a bit more in line with what a mic preamp wants to see.

Many Audio Interfaces can accept Mic or Instrument level signals and have a small switch to go in between each one. That way you can connect a mic or instrument without a DI box. So why use the DI box at all? Well, the DI box allows you to put your guitar directly in to a Mic level input channel. The difference is quite subtle. You may not even hear it to be honest. However, it is there.

Some Mixers and older audio interfaces don’t let you switch Mic/Instrument and just take care of it when you plug in to them, as best they can. If you're using a mixer or interface without dedicated mic/instrument switching, a DI box can come in very handy.

Also, a DI has another benefit, it balances the unbalanced signal coming from a guitar. A balanced signal can travel much further than an unbalanced signal without picking up lots of extra noise. If you run a guitar cable more than 20 feet, you can pick up all sorts of noise that you don’t want. So if you use a DI box, you can keep your cable run to the DI Box very short, and then use the output of the DI box to travel along a long cable without picking up extra unwanted noise.

When comparing a balanced and unbalanced signal, the unbalanced signal has a bit of high end roll off. So it can negatively impact your tone on long cable runs. The DI box allows better tone over longer distances. So if you need your signal to travel a long way using a cable, a DI box can be very handy indeed.

So far we have been talking about passive Di Boxes. That means a DI box without any external power source required. These units can eliminate ground loop noise as they dont connect to a power source.

An active DI Box makes use of some type of power source. It can be a battery or wall power. Active Di boxes work better, in general, with passive sources, such as a guitar or bass with passive pickups. Passive DI boxes work best with active sources such as guitars and basses with active pickups. This is not a hard and fast rule though. The benefits of a passive DI with passive sources is very real, although subtle.

For more info, here is a video.

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[klasaine]

DI boxes are probably the least 'sexy' but most useful piece of gear that one needs.

*An interesting bit of info regarding exactly what a balanced signal is ...
There's a transformer in a DI. When you run your hi-z guitar into a DI it splits the signal into two and reverses the polarity (phase) of one of the signals. When your signal gets to the other end of that XLR cable run, whether it be to a recording interface or a FOH mixing console, the phase (polarity) is flipped again and that effectively cuts (phases) out any noise (RFI, electro-magnetic, etc.) that was introduced/picked up in the long cable run.
Pretty ingenious!

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This post has been edited by klasaine: Jun 29 2022, 05:39 PM

[jstcrsn]

DI boxes are probably the least 'sexy' but most useful piece of gear that one needs.

Yep... Got 1 .. okay 2

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[Todd Simpson]

That's very cool info on how the DI actually works it's magic!

DI boxes are probably the least 'sexy' but most useful piece of gear that one needs.

*An interesting bit of info regarding exactly what a balanced signal is ...
There's a transformer in a DI. When you run your hi-z guitar into a DI it splits the signal into two and reverses the polarity (phase) of one of the signals. When your signal gets to the other end of that XLR cable run, whether it be to a recording interface or a FOH mixing console, the phase (polarity) is flipped again and that effectively cuts (phases) out any noise (RFI, electro-magnetic, etc.) that was introduced/picked up in the long cable run.
Pretty ingenious!

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Don't miss today's free lick. Plus all our lessons are packed with free content!

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