Starting back in the '70s, the brand Neve and their preamps and consoles continue to hold prominent status when it comes to recording equipment.

So it is unsurprising that their Direct Box would rank high in this list, thanks to its impressively high Gearank Rating, which includes many experts recommending it.

The first thing you notice is how high quality the unit is. The enclosure, jacks, and switches all feel solidly built and made to last.

Interestingly, what makes this unit special is not necessarily its straightforward Direct Box functionality. Rather it is its amplifier section which features the same Class-A discrete FET amplifier as found on popular Neve consoles.

Because of the design, the RNDI subtly adds harmonics to the signal. It doesn't come in the form of a perceptible shift in EQ. Rather, it feels like even raw tracks have more "depth" thanks to the harmonic content. This makes a great choice as a critical tonal element with regards to depth and richness. I might go so far as to say it imparts "preamp-like" characteristics to your sound. Recording multiple tracks with it helps blend together instruments in the mix thanks to the similar harmonic content.

This means that the RNDI isn't exactly the most transparent. While having a bit more depth from the get-go actually helps the mix down the line, this might not be what you're looking for. However, having a warmer and bigger sound is harder to do in the mix. Even then, it's not as good as having it upfront.

I highly recommend the Rupert Neve RNDI for bass and guitar, but it can also work well with any instrument. If you are looking to add more juice to your recordings or even your FOH sound, then the RNDI is highly recommended.

Specifications

• 48V phantom powered active circuitry
• Ground Lift switch for both speaker and instruments
• 1/4" Input and Thru-put jacks, gold-plated XLR output
• Steel chassis
• Weight: 1.5lbs

The Samson MDA1 is a simple active direct box powered by a phantom 48V or a 9V battery.

The MDA1 can reproduce frequencies as low as 18Hz, making it ideal for recording bass DI tracks

The solid metal enclosure ensures long-term durability.

The MDA 1 is built like a tank and will definitely last several years. True to the specs, the MDA1 can preserve deep subfrequencies with good detail without being too overwhelming. The relaxed low-frequency roll-off is essential for bass tracks.

Despite the solid enclosure, the jacks are the first thing to watch out for. More often than not, these are usually the first to fail (although on the MDA1, I assume it will be years before that happens). Luckily, these are easily serviceable/replaceable by a technician.

If you're looking for an active direct box that is able to reproduce sub-low frequencies with ease and is built to last, the Samson MDA1 is a great budget pick. Another good cheap DI box to consider is the Behringer Ultra DI di400p.

Specifications

• In: 1 x 1/4" (instrument), Out: 1 x 1/4" (thru), 1 x XLR (balanced out)
• Powered by 48V Phantom Power / 9V battery
• Metal enclosure
• -15dB pad and ground lift

Expanding on the RNDI (also covered in this guide), The Rupert Neve Designs RNDI-S is the stereo version of the RNDI.

For stereo DI, stereo coherence is important, especially during recording from stereo sources like effects, keyboards, loops, and samples. Having stereo matched signal reduces phase cancellation and comb filtering. The better the phase coherence between channels, the better stereo tracks fit into the mix.

I can't think of any cons aside from the price, which puts it out of reach of budget-minded project studios.

Despite being at the more expensive end of our list, many users praise the RNDI-S for its sonic enhancements, phase coherence, and build quality. If you want to upgrade your already stacked studio, get it; it might just be the small improvement your workflow/signal chain needs.

Specifications

• 48-Volt phantom powered direct box
• High rail voltage design to avoid clipping
• 80Hz highpass roll-off filter for reducing mud and increases headroom
• Input 1/4", Outputs XLR, 1/4" thru
• Weight: 1.55 lbs

Things to Consider when Buying a DI Box

So what is a D.I. Box for anyway?

The main job of a D.I. Box is to convert your instrument lead (1/4" TS) signal 'directly' into the microphone inputs (balanced 3-pin XLR) that a mixing console typically has. Unlike a simple headphone adapter (1/4" to 1/8") it doesn't just need to change the size or shape of the connectors, it has to convert the differences in impedance and voltage between the two sides of the connection to achieve a balanced signal. The details of how it does this are beyond the scope of this guide but if you want to delve further into the topic then look at this DI article on Wikipedia. The main thing to consider is that due to electrical designs this conversion process can influence the tone of your instrument (in a good or a bad way) and that's why getting the right DI Box is important.

Apart from just "getting the signal to the desk" a DI Box (also called Direct Box, Direct Input, or Direct Injection Box) can also have several other advantages. Firstly the balanced XLR connection is much better for running cables over long distances without picking up noise and interference. Guitar leads, for example, can lose some sound quality at around 20 feet (6m) so if you want to cover more distance than a balanced XLR cable from the Direct box is better. Secondly, many DI boxes (especially passive ones) isolate the input and the output circuit which can help prevent ground loop hums and other electrical noise from creeping into the sound system.

Passive vs Active DI Boxes

There are two types of DI boxes - Passive and Active. Passive DI boxes work with no external power source, while active direct boxes require phantom power, a battery, or a separate power supply. An Active D.I. box offers more functionality and improved sound quality, while Passive Direct Boxes offer straightforward functionality without worrying about the power supply. The general rule is to use an Active D.I. Box for instruments with passive pickups and a Passive Direct Box for instruments with active pickups and electronics. If you're wondering whether your instrument is passive or active, it's simple - if you have to supply power or put a battery in, it's active; otherwise, it's passive.

Input/Output Ports

The most basic form of a D.I. Box usually has one input and one output that goes straight to the mixer. As the price increases, they offer more options, including a separate output for amp or monitoring. At the same time, some even have multiple input/output options for complex rigs and multiple instruments. You'll want a D.I. Box with the right amount and type of input for your needs. If you're using a single instrument like electric bass or acoustic guitar, a compact, straightforward D.I. Box would be more than enough.

Ground Lift Switch

The more music equipment you manage, the more voltage differences there may be between them, and these differences are perceived by the mixer as hum and noise. Since Passive DI boxes are transformers, they provide automatic ground lift for instant noise and hum reduction, making them important in keeping stages and studios quiet and clean sounding. An Active Direct Box also provides this feature, with some of them having a ground lift switch that isolates the signal ground from the unit's chassis ground.

Size

As mentioned above, more features and connectivity options require space, increasing the Box's size. It is important to find one with just the right connectivity and features packed inside a unit with a size that's comfortable for you to use or carry around.

Are Regular DI Boxes and Reamp DI Boxes Interchangeable?

Because of the different purposes of both devices, it is best to choose a box specific to your needs. Direct boxes are for feeding signals into a recording interface or mixer. At the same time, Reamping DI Boxes convert pre-recorded signals for going into amplifiers or effects processors - these require a different impedance level to mixing consoles.