What is a DI (AKA a Direct Box)? A DI is basically a device that in the most basic sense electrically isolates and transforms unbalanced line level signals (signals from most stage instruments and most consumer electronics) to balanced line level (on both powered and unpowered lines) singnals commonly found on PAs and stage mixers used for mics. There are two categories...Passive and Active. Passive DIs do not require any addition power source like batteries or AC input. They are simply a transformer that transformed the input signal to an output signal. I will skip the physics of it though. Active DIs are a little more complex and generally cost more. Sound quality on cheaper models can be horrible. These DO require additional power such as batteries or "Phantom Power" on the higher end units. Without getting too deep into the physics here, these depend on the unit's "rail voltage" to prevent clipping. The more dynamic the insturment and performance, the more rail voltage you'll need. This unit features a rail voltage of around 9V which is much higher than comparable Active DIs. This is important with the modern generation of pre-amplified (powered) acoustic guitars, active basses, ect as these signals can be quite dynamic electrically. Why do you need a DI? Whether your using an instrument or a multimedia device like a DVD, iPod, or laptop...these will almost always be unblanced line level outputs either thru 1/4" jack, 1/8" jack, or RCA jacks. Just using a cable adaptor to mate these with the common 3-pin XLR for balanced line level signals found on PAs and mixers will at the very least create problems with loss of signal, and unwanted buzz and hum. And at the worst (and actually very likely with Phantom Power) short out your device. PAs that use Phantom Powered mic lines and these will instantly overpower any device mentioned above. Instead you need something to transform and isolate the two halfs of the system. This devices transformer and circutry does just that. Also even on a mic line that is unpowered, there is a risk to the pre amp in the PA when sending unbalanced line level signals to it. In other words... Buy a DI! The details. This unit is a powered unit that requires 48V Phantom power to be on the XLR line to supply the unit with power. It has an indicator light that shows Phantom power but stays on only momentarily. On the input side you get a 1/4" in and 1/4" thru for passing to a stage amp. Or you can use "merge" button and combine the two jacks to convert a L and R stereo signal to mono. Nice for multimedia and keyboards. I'm using a Hosa 3.5mm TRS to Dual 1/4 in TS (1/8" stereo jack to dual mono 1/4" jacks) for one of my applications. On the input side is a "pad switch" to signals that are really dynamic and may potentially clip. On the Output side is a single balanced XLR output (1 channel mono), a 180 degree "flip switch" for reversing polarity to work with foreign made sound equipment. It has a ground lift switch to isolate grounds and get rid or noise due to ground loops. Because it is a powered unit and has electronic circuitry they have included some extra isolation to protect the signal and preserve that continuity for the power supply. The device is built to isolate grounds automatically, but if you still have noise you suspect due to grounds, try this. Lastly it features a low cut filter button that is used in preventing feedback. It's small in size, about 4"x6"x1.5" and roughly 2 lbs. It's made of a solid steel case to protect it from damage on stage while at the same time create an "EM cage" to shield the internal electronics from outside interference. This is my 3rd DI from Radial. I have to say at this point I'm a fan of their gear. This unit is definitely a professional quality DI with a reliability and sound quality that tour musicians require but at a price point just about anyone can afford. I bought this one to play by Italia Mondial through, it has an active pickup inside the hollow body and I have to say, it sounds tremendous played through this box. BTY, if you're looking for a Passive DI (one that requires no external power), look into the JDI by Radial. There are cheaper models from them, but this one sounds great no matter what you drive through it. Read more

Amazing sounding DI box. Really can't believe how much difference this DI box makes. Awesome on bass guitar. Read more

Works great, excellent quality, great brand Read more

Would Buy again Read more

Great unit! Our band has just recorded the bass guitar tracks by using this unit and results are amassing. Phantom power makes a big difference. Most of our band members are using Radial brand. Read more