DI BOX: The best direct boxes

DI BOX: The best direct boxes

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Among the dozens of objects that every musician uses, there are some that are really difficult to fully understand, we are talking about the DI boxes. You can find them in every plant and in every recording studio, but how many of us really know how to explain what they do? If you are interested in finding out, keep reading this article and you will certainly not be disappointed ….. let’s start from the basics


The main purpose of a direct box is to transform the signal from an unbalanced instrument into a balanced one. The way it helps the musician is as follows: on stage, especially where the distances between mixer and instrument are high, it sends the balanced signal to the mixer output and the unbalanced signal to the amplifier. In the recording studio it works virtually identically, except that the balanced signal is sent to the audio interface. In both cases with the direct box it is possible to send guitar signals for example over very long distances, without accumulating noise.


This is the real question that everyone is asking, what is the difference between active and passive direct boxes. Yes you guessed it, the active ones require an amplifier to work, the passive ones don’t, so I take a passive one, at least I don’t need the power supply and I save … well they are not exactly the same thing and therefore they do different things too, let’s see them together :


The first rule to keep in mind is that active DI boxes work best with passive tools, such as:

  • Electric guitars
  • Bass
  • Rhodes plans

And this is why

Passive instrument pickups have a weak output signal, which is why they benefit from amplifying it via an active DI.


As you may have guessed, they are the active ones. In this category we can therefore include active basses, keyboards and electronic percussion. Since the preamps built into these instruments directly deliver a stronger signal, they do not need the amplification provided by active DIs. Also it is It is possible to add that, since passive DIs have more “air”, they have the ability to manage signals without distortion; but when passive DIs distort, they produce analog distortion, hence pleasant, not like that resulting from distortion of active DIs.

This is the first scenario where passive DIs are ideal, the other is that of concerts….


The problem of the DI is precisely to supply the power they need, especially on stage and the batteries always run out at the least opportune moments and are in any case expensive to replace.

Passive DIs working without power have none of these problems. Another reason passive DIs are better is that they eliminate any noise from other electronic devices.


A common thought is that all direct boxes are identical to each other, thinking that all these devices all sound the same, the truth is that some sound really good, others really… ..I think you understand.

One of the main features to look at in a DI box is the quality of the transformer, in normal conditions of use the transformers are constantly exposed to interference that affects the sound in a negative way; one of the major sources of interference is the magnetic field created by the amplifier. In order to overcome this problem, quality transformers use shielding on the outer casing in order to be isolated from the outside world. The problem is that these isolations are expensive, so if we want a professional DI box we will have to spend some money on it, but we will be rewarded by the quality of the device itself.


  • Radial ProDI
  • Radial JDI


As previously mentioned, a big problem of active DIs is to work in live situations, so a good active DI must be able to work in these situations as well.

For example in most active DIs, 48V phantom power has a tendency to pass hum from system power, but it is not possible to cut ground (eliminating hum) while keeping phantom power on. .

To stem this problem, the Radial J48 converts 48V phantom power to alternating current using a power selector.

Another problem with phantom power is that the internal voltage is reduced, having a device with much less air available than a passive DI. The Radial J48 it overcomes this problem with a power supply circuit that creates an internal voltage of 9 V, thus obtaining a headroom typical of a passive DI.

It is therefore not surprising that the Radial J48 – ( Amazon ) is the standard in its field.

Alternatively, here are some other great active DIs :


Acoustic guitars are usually amplified by the use of passive piezoelectric pickups, one might think, also based on what we have said so far, that an active DI would be the ideal choice.

In reality, these pick-ups with particular characteristics have impedances that are higher even than some active pick-ups; therefore there are acoustic DIs on the market, designed specifically for this instrument.

These DIs have the ability to capture and render in great detail the high frequencies that characterize acoustic guitars so clearly.

Among the best models on the market I recommend the following :

  • LR Baggs Para DI – ( Amazon )
  • LR Baggs Venue – ( Amazon )
  • Fishman Aura Spectrum DI – ( Amazon )
  • BBE Acoustimax – ( Amazon )
  • Radial PZ-DI


If you need to process stereo outputs such as those of a keyboard or electronic drum, use a DI designed for this purpose; in fact the stereo DI boxes process both channels in a single device.

Another interesting feature of the stereo DI is the ability to mix the stereo channel into a single MONO output, a very interesting function when you have to play on large stages, where the audience is spread over a large area.

If you are looking for a stereo DI, I recommend that you evaluate these two excellent options :


All guitarists know how difficult it is to find the perfect tone for their guitar; and this is a problem, as often musicians have their best performances with the first recordings and these are often lost due to the search for the best sound. To overcome this problem, a method has been developed to allow you to work on the track after it has already been recorded. John Cuniberti created a device called “re-amp” for exactly this use.


you take a guitar track without effects, previously recorded and send it to the re-amp, this takes the balanced signal and converts it into a new guitar signal, which can be sent to the amplifier with a second cable. At this point it is possible to loop the pre-recorded track and you can set up your sound at your leisure. Once you have found it, you can re-record it on a new track.

This is a recommended re-amp for you:

Palmer Daccapo – See price or buy


Sure oversized for a mid-sized home studio, but rack-mounted multi-input DIs are the best in the direct box world and can offer tremendous benefits.

In professional recording studios and on big stages, these devices allow you to connect guitars with multiple amps, with multiple reamping loops. You may never need such a system (I hope so for you), but it’s still good to be aware of their existence.

All the best DIs in this category are produced by Radial and below you will find some recommended by us:

  • JD7
  • Pro d8
  • JX44


You will have easily noticed how the prices of the various DIs available can range from 40 to over 1000 euros, so the question that arises is: how much should I spend?

From our guide it seems that the Radial has all the solutions and answers regarding the DI boxes and they actually answered this question as well. In their opinion you should use the 5: 1 rule, that is, for every 5 euros spent on your instrument you should spend 1 on the direct box. So if we have a 1000 euro guitar we should pair it with a DI box that has a price around 200.

This all makes sense, doesn’t it? Now we also know which one