We seem to live in an age where every single audio interface has some sort of Hi-Z/DI/Instrument input, for you to plug a guitar/bass/keyboard in, so the real question is, do we still need stand alone DI boxes?That’s where a product like the Pro48 Active DI box from Radial Engineering enters the discussion. The Pro48 is their slightly more budget active DI, but does it have a place in the small home studio? Should it replace your interface’s Hi-Z input? And is it any good?
Design & Build Quality
Much like the TARDIS, the Pro48 is a pretty unassuming blue box, and one of the first things you will notice is just how solidly built this unit is. Much like it’s more expensive brothers and sisters, the Pro48 features a ‘bookend’ style, which when coupled with the internal ‘I-beam’ design, and the 14-gauge steel used in production, makes this thing practically indestructible. Internally the ‘I-beam’ design also keeps the internal PCB safe, preventing it from any external stress, transferring to solder joints and components. I am by no means a small guy, and even my exceptional weight stood on this DI box won’t be causing any damage anytime soon. Whether you are an amateur or pro I’m pretty confident that this device will stand the test of time, and the rigours of recording, touring or gigging, whether you handle it with care, or happily chuck it loosely in your pedalboard, or in your guitar base (RIP your guitar if you do that though!)
Regarding connections, the Pro48 offers exactly what you would expect; an input on a ¼ jack and a balanced XLR output. It also features a ¼ ‘Thru’ output that essentially mirrors the input. In practice this allows you to take a DI of an instrument and use say an amp as well. One thing I found myself doing quite a bit was taking the balance output as a DI track, and using the thru to drive the Unison input in my Apollo Twin interface, this gave me a dry DI track, and an ‘amp’ track. from the connections, the Pro48 also features two push button switches; a pad of -15dB, which is perfect when working with active guitars and basses that can have a pretty hot output, and a Pin 1 ground-lift to combat any ground hum that you might encounter.
If I were designing this product myself, I would love to have seen two more features; a low-cut switch and a phase flip button, but based on the build quality of the unit, I can understand, at this price point, why they were omitted. If these are features you cannot live without then I would recommend looking at either the Radial JDI (if you want a passive DI) or the J48 (if you want active) but both of these do cost around £100 more than the Pro48.
In Use
In actual use, I was more than satisfied with the performance I got from the Pro48. Used across multiple sources including Electric guitar, Acoustic guitar (via its piezo pickup) and keyboards (in mono) gave the instruments the ability to be themselves. It didn’t add any cheap nasty colouration or lose any top-end, which is something cheaper DI boxes and Instrument inputs on interfaces can sometimes be guilty of. And it isn’t only the top-end that shines, the low-end is kept tight and detailed. Transient detail is preserved nicely, and the unit offers plenty of headroom for a high dynamic range. This headroom does allow high-gain active instruments the room to breathe, and if you find yourself distorting the unit (which does a fair effort to do), the -15dB pad works nicely to open up some more room.
Final Verdict
The Pro48 Active DI Box from Radial Engineering is something I would definitely recommend for someone who wants a good-clean DI in the studio, or even on stage. It may not be the most exciting piece of studio equipment, but that’s the point. For every bit of vintage fancy gear, there is another piece of basic gear that holds down the fort. Sometimes ‘Mr Reliable’ is what you need.
And for around £135, you are definitely getting a unit that does the job and does it well. And it has the added bonus of being built like the proverbial outdoor toilet. I myself have been using the same Pro48 in both the studio and live for around the past 15 years, and aside from a few cosmetic scuffs, the unit is still going strong.
Now, in terms of alternatives, in a similar price range, you have products such as the BSS Audio AR-133, which offers similar features, and the Warm Audio WA-DI-A, which offers similar and additional features for around £10-15 more.
From Radial Engineering themselves you have the ProDI, which is around the same price and is essentially the passive version of the Pro48. If you really want a big improvement over the Pro48, you can also jump up to the J48 or the JDI from Radial, but you are looking at around £100 extra for the added quality and features.
Radial Pro48 £135
Radial Engineering Pro48 Product Page (Opens in new tab)
