Radial Engineering R8001010JDI Single-Channel Passive Direct Box with Jensen Transformer

The other reviewer gave excellent specifics about the tone and feel with vintage instruments and amps. This is what this box was designed for and where it will really shine. My application is a little different. I wanted a quality "passive DI" for multimedia and for the occasionaly electric-accoustic guitar input.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 transforms 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 really 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 are essentially a pre-amp and depend on the unit's "rail voltage" to prevent clipping. The more dynamic the insturment and performance, the more rail voltage you'll need. As I said though, this is passive DI so it's produces a nice subtle sound curve even as it reaches satuaration (passive DI speak for overdrive.) Rather than clip they "fill up."Why do you need a DI?Whether your using an insturment 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 cause you to loose sound quality and level. Potentially buzz and hum, possibly (and acutally very likely) short out your devices audio output OR even worse, damage the input line on the PA costing you dearly. Many professional mixing consoles use Phantom Powered mic lines and these will instantly overpower any device mensioned above. Instead you need something to transform and isolate the two halfs of the system. This devices transformer and circutry does just that. Also there is an electrical difference between balanced and unbalance signals. This DI does, convert the unbalanced input to a balanced output sent over XLR.The details. First off, I pleased to say that this unit is the newer model JDI. This is not the mk3, but the next gen. I'm very happy about that dispite the description. Inside this box is a genuine Jenson audio transformer, reguarded for their superior sound quality especially with vintage equipment. 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 my application. On the input side is a "pad switch" to soften sounds like MP3 and CD players. 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. The device is built to isolate grounds automatically, but if you still have noise you suspect due to grounds, try this. Lastly is a speaker parallel button that I'm not entirely sure what it's used for. 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.All in all it's a great box with excellent sound quality. It's far more than I need, but I hope to grow into it. For users that don't want to spend an arm and a leg Radial does make really great DIs that aren't as expensive. For AV/multimedia users there's the ProAV1 which is purpose built as a swiss army knife solution for hooking your audio out to any PA or stage mixer. For instrument users there's as many DIs as stars in the sky to fit any budget.

This is the best sounding passive DI I own. I tested it side-by-side with several other DIs, both active and passive. The sound of this box trounced them all with clean, clear, pure tone. I use JDIs live and in the studio. On stage, I have an effects unit for my sax that only has stereo 1/4" outputs. I plug them into the "left" and "right" inputs on the JDI and use the "merge" button to combine the stereo inputs into a mono XLR out. It works great and kills two birds with one stone. In the studio, I use it on things like acoustic-electric guitars, and active-pickup basses. It's a solid workhorse that won't let you down.

Nice... Nice product!!!!. The result was reduce 80% the interferences comming from my guitar (the cage inside my guitar, made by copper tape, shield it, but just make a properly ground and other kind of noise was present). This passive direct box gives sound clarity and definition to guitar signal, so, a warm and balance signal go inside the effects, besides ELIMINATES THE GROUND LOOPS THAT LAPTOPS AND OTHER DEVICES CREATE, however take in mind.... is completely necessary connect the XLR out to get results of 100%, in other way, you'll notice a effectivity of only 80% on ground loop and noise reduction. Finally have to comment that the noise gate effect is only needed at 30% after use this direct box, before, was mandatory use it until 100%. Guitar signal does not get any kind of weird color, remains pure. Last step in my effec loop before recording, it is to use the radial StageBug® SB-6 Isolator to kill the noise spreads from effects!... Thx

I always use a DI box to isolate my acoustic guitars from the mixer. It precludes any issues with phantom power (kind of a better safe than sorry mindset).I had a Whirlwind DI box I bought a few decades back and didn't think much of it. However, I saw a recommendation for this device elsewhere on Amazon and gave it a try.I'm glad I did. The sound quality is orders of magnitude better. The case is rugged as well. I highly recommend it.

HI,I picked up the Radial JDI to use with my Rare Earth Banjo pickup from Fishman. Wow, right out of the box this DI sounds better than any Ive used before. For an active pickup like the Rare Earth one, this Passive DI is perfect for taming and really bringing to life the banjo like been looking for! it really sounds good, natural, and musical! I was using an LR Baggs Para DI but never got a good banjo tone for live settings. Found out I was using an Active DI instead of Passive and the difference is very noticeable to my ears. The Radial JDI definitely brings a professional sound and build, highly recommended for situations like mine.

Wish I had known about this item a long time ago. I am using this box for a Fender Jazz bass. There is absolutely no hum associated with the signal coming out of this box (can't say that about the other DI's I've used in the past), nor does the signal appear weak. The construction of the box itself is nothing short of the highest quality -- as sturdy as anything I've seen (and I've seen quite a bit in my 40 years as a bassist). Don't let the price fool you. If you are looking for a DI that delivers a pure and strong signal, it would be worth your time and investment to give this a try. Chances are you won't be disappointed, and your sound man will love it.

Arrived a tad shaken up in the box, but seems to work fine. I like the form factor a lot. Surprisingly thoughtful use of the rubber pad on bottom for vibration isolation and sticking to somewhat irregular surfaces. Sonically, what can you say about something in this product category except it's very transparent (no color/EQ added that I can hear) and the output is quiet.