DIVerse, the armored DI boxes made by OteCables

By an interesting coincidence, three DI boxes by a Czech company OteCables made it to my chopping block for review. Some time ago, I was looking for any passive DI boxes I could find to compare, and I got a message from Filip Otevrel and Petr Valihrach. They offered to send me their new line of DI boxes, which they poetically call DIVerse. Even though the price is fairly north of the other DI boxes I got, my curiosity got the better of me. I had a conversation with the fine gentlemen from OteCables and a few days later, a got a visit from a facemask-wearing delivery man with a package from Brno.

If you haven't heard about OteCables, it's a subsidiary of the live sound and rental company OteSound., who basically decided to manufacture their own cables, custom splitters and other gear, with their latest addition being the aforementioned line of DIVerse DI boxes. As a proud patriot, I am always happy when a local company manages to design and build a world-class product that becomes successful on the international market. I can safely say that I can get behind the first part of the sentence (see the rest of this review). As for the second part, I think that is only a matter of time. But let's not get ahead of ourselves (or as my kids would say, no spoilers!) and let's take a look at the three little bricks that landed heavily on my table after opening the package. Thankfully, I have a massive wooden table that can take the beating.

DIVerse, the diversity of divine verses

Before we get to each individual DI box, let's talk about what they have in common, which is quite a lot. Even after a brief look at the chassis, it is obvious that the construction is very well thought-out. All the models have the same chassis, the only difference is their color, and of course, the internal components. The boxes themselves are protected by a gold outer chassis, similar to the boxes made by the Canadian company Radial, but here, the engineering is amped up to a new level. Because it is difficult and expensive to manufacture four different kinds of chassis for four different versions of the DIVerse, the outer chassis is the same for all models, and the inner chassis just slides into it to create a fully-armored DI box. Maybe you think that fawning over such a small design feature is ridiculous, but from the perspective of the manufacturer, it's genius-level engineering. Try coming up with something like that on your own, see how far you get.

I already mentioned the Radial DI boxes, whose passive JDI direct box is an industry standard that is often requested in professional riders. That means that any professional DI boxes on the market will be compared to the JDI, and that includes the DIVerse. The first thing that piqued my interest is the fact that the metal plating is 0,3 mm thicker on the DIVerse. Radial's chassis is 2 mm thick, while the DIVerse is a little thicker, precisely 2,3 mm according to my measurements. I don't know if this is a countermeasure to deal with the infamously dire environment of Southern Moravia, but I feel that this is a little bit of an overkill. If I was to use the old cliché that it's “built like a tank”, I would also have to add with the same breath “also as heavy”. I'm not a fan of conspiracy theories, so I will interpret the fact that the column for weight in the data sheet is not filled out as a mere coincidence.

Comparing the size of Diverse and Radial JDI

I weighed the single-channel DIVerse 1ch HiZ (I would like to sincerely thank my wife, Eliška, for lending me her kitchen scale) and I got a reading of 813 g. For the sake of comparison, the Radial JDI is 670 g, which is definitely not featherweight, but it is a different weight category. Here, we get to the first gripe I have with the DIVerse. I understand that the guys from Otesound are used to massive splitters on wheels and a bunch of stagehands to do the heavy lifting, but what about us freelancers? A while ago, I weighed my “audio first-aid kit” and the scale got up to 17 kg, which in itself makes for some uncomfortable schlepping around, and that is even without any of the DIVerse DI boxes.

Besides the construction, what all the boxes have in common are the components. While Radial uses its own C-tek transformers for the cheaper lines of DI boxes, and equips only the pricier models with their Jensen transformers (did you know that JP Cabletek, who owns Radial, bought the company Jensen in 2014?), the guys and girls at OteCables have a different approach. Top quality, permalloy-shielded transformer by the Swedish company Lundahl are at the heart of every DI box in the DIVerse line. I consider this a great decision in every respect, which is also shown by the comparative testing.

The weight is really impressive


Can I go a little off-topic here? Isn't it interesting how many companies making amazing transformers are there in the Anglo-american world, while here in Europe, as far as I know, there are only a few manufacturers. Besides the aforementioned Jensen transformers, which serve as an industry standard for the American market (I will omit their OEM, JP Cabletek), there is also Edcor, Cinemag, Crimson, Allied, Hammond in Canada, Sowter, Carnhill, OEP, VTX in Britatin... And in continental Europe? Besides the undisputed industry leader – Lundahl, the only ones I am aware of are Haufe, Lehle and EXPERIENCE Audio in Germany, Amplimo in Netherlands and Neutrik in Lichtenstein (although here I have trouble believing that these are not imported from distant lands). Do you know of any other manufacturers of signal transformers suitable for DI boxes in continental Europe, namely in central and eastern Europe? If you do, please leave a comment bellow the article.

To sum up, using Lundahl transformers makes sense both because of their availability and their quality, and I can only commend the designers for going in this direction. All other components are of similar quality, mostly for protection (from DC voltage on the input or over-voltage), or other functions such as PAD (-20dB in all models). Overall, I have to say that in my humble opinion, the engineer (Karel Stouda) did an excellent job. The PCBs are designed practically and wired cleanly as far as the eye could see (which is about a centimeter behind the chassis) and contact points in the box are padded with copper plates to ensure perfect grounding. The manufacturer also remembered the little details, like a neoprene anti-slip surface on the bottom, and screw sockets on the sides that let you attach the DI box to a wire for theft protection, if needed.


The manufacturer did not forget to include anti-slip surface

I would also like to commend the connectors. Where Radial Twin-ISO uses standard XLR connectors without accidental disconnect protection, the DIVerse 2ch ISO uses connectors with protection. The same can be found on the DIVerse 1ch, which even has a 6,3mm TRS output jack, so the when lead singer passes by the cable that you forgot to fasten with gaffer tape, he trips over it and safely falls into the arms of his many fans in the audience while they cheer him loudly, but the cable stays in the socket. The build quality of the connectors, even though they do not have a typical brand-name written on them, seems to be very high-level. In contrast to many other manufacturers (Radial not included) who use TRS jacks that are directly mounted to the PCB and inevitably lose their integrity over time, everything is how it should be in the DIVerse, and all the connectors are mounted onto the metal chassis (albeit only with the plastic nut of the jack connector). There is one more thing I would like to thank the designer for: I count myself among the paranoiacs who use DI box even when taking a XLR direct out from AER or Gallien amps, just to be sure. Standard passive DI boxes usually provide only jack sockets in front, which makes my life a little harder because I cannot use a standard mic cable, so I always consider the XLR input (separate or in XLR/TRS combo jack) as a very useful addition and frankly, it baffles me that so many manufacturers do not include this feature.


The DIVerse uses sockets with protection against accidental disconnect

There is one thing I have to mention, so that I'm not only singing praises. I am not a fan of the labels, not only are they small, but often they are insufficient. For example, in the front, we have two TRS input and one XLR input, without any explanation other than a laconic “in” on the edge of the outer chassis. I hesitated upon first seeing the inputs, and contemplated the intent of the author, whether all the inputs are parallel or if there could be any surprises. All the while it would be enough to connect the sockets with a T shaped symbol or write “parallel” or “thru” somewhere on the chassis. Even though I commend the connectivity of both the input and the output sections, it is not clear at first sight what is going on with the connectors. Needless to say, in the manual, all the connectors are described in great detail, so after being acquainted with the unit, this will not be a problem.


The labels are not overly detailed

Before we get to the individual models, let me just mention one more sweet treat. While reading through this review, you might have been surprised that I dared to open up the chassis and take a look at the interior of the DIVerse, but the manufacturer even encourages the user to grab a screwdriver and get to the insides of the product. The transformers can be connected in two different ways, using a jumper cable that is included on the PCB. I really admire this “guerrilla” approach, but I cannot help but think if there wasn't any better way to solve this issue, like a properly protected toggle that is sunk into the chassis, similar to Radial SB-1's ground lift button. Not that I don't like to screw stuff, but the gold screws in the DI box are so soft and small that unscrewing them cleanly took a lot of effort and courage, and I wouldn't be comfortable performing the operation more frequently.


A great feature – jumper cables to switch transformer output ratio

So, you see that the three armored dreadnoughts have quite a lot in common, and you could basically apply three fourths of the review to all of the models. But here, we reached a point where we start talking about the differences between the particular models.

DIVerse 2ch ISO

One does not have to be a crossword puzzle champion to deduce by the name the purpose of the vibrant red DI box in gold armor. It is designed for galvanic separation of high-level audio signal sources, like inputs of professional mixing consoles and PA processors. I didn't come up with that, this is taken directly from the manual. This means that it will come in handy anywhere, where there is a need to galvanicaly separate two different worlds of electricity (to combat ground loops or mutual interference) while maintaining the the same signal level and a balanced connection at both ends. We can surely think of many real life examples, like connecting to video platform for streaming, which requires a master output from your mixing device. As you probably guessed, it's a stereo DI box, because even though there were various remarkable experiments, stereo is still a world-wide standard in audio.

DI Box OteCables DIVerse RED 2ch ISO

Included Czech manual is a big advantage for me as an author, and because I am not yet being payed for the reviews at FADER.cz, instead of trying to find a way to explain technical details in my own words, I will just quote the relevant parts of the manual.

This is a two-channel passive DI box, designed primarily for galvanic separation of complex stereophonic signal, or two channels of live-level signal, with high resistance against overloading, for example by a signal from a PA system. In the output section, there is a “lift” button (lift ground on pin 1 on output connector). Internal transformer is protected against distortion caused by DC magnetization due to residue DC voltage of some signal sources, and against damage caused by discharges of static electricity that can happen in larger installations. For signal processing, the Lundahl LL1588 transformer is employed.

From the manual DIVerse RED 2ch ISO

This short piece of text, along with everything I said before, tells you all you need to know about the DIVerse 2ch ISO. What can possibly leave you wondering is why there is no polarity switch function. It is not included in any of the DIVerse DI boxes and frankly, I always consider it an advantage. I don't know about you, but I was recently schooled so hard by two active DI-boxes that had the polarity unwittingly switched, that I now consider the polarity switch on a DI box my mortal enemy. Moreover, in these days it is never a problem to switch the polarity at the mixing board. Besides, I always carry two polarity flippers in my 17kg emergency suitcase. Looking at the front panel, I keep thinking how cool it would be to also include TRS jack inputs in front, which would further enhance connectivity of the device. All in all, TRS jacks are still used often and why not include the option to easily use the DIVerse 2ch ISO with stage pianos or older DJ turntables.

DIVerse with output impedance ratio 1:1

The blue knight in goldish shining armor is available in both single-channel and stereo versions, and because the number of channels is the only difference between the versions, I requested only the single-channel version. In contrast to its fully balanced red comrade, the blue-jay is primarily designed for connecting standard unbalanced audio sources, like keyboards, sound interfaces, guitar “stomp-boxes” and so on, where it has better protection against overloading. This DI box also takes unbalanced inputs signal, and turns it into a balanced signal.


DI Box OteCables DIVerse BLUE 1ch

From the manual DIVerse BLUE 1ch

For connecting instruments with passive pickups, the version with high impedance input and transformer ratio of 5:1/10:1 is more suitable (labeled before as DIVerse HiZ). If the incoming signal is too hot, it can be reduced by 20dB using the PAD button. In the output section, there is a standard “lift” toggle (lift ground on pin 1 on output connector) for eliminating ground loops. In case of extremely long signal runs or connecting low-impedance signal sources, the DIVerse 1ch is allows you to internally change the output transformer ratio to 2:1, with the corresponding 6dB of attenuation. For signal processing, the state-of-the-art Lundahl LL1570 transformer is employed.

A classic line DI box non-plus-ultra, with a handy feature of switching the transformer output ratio. I wish it was possible without using a screwdriver.

Instrument DIVerse 1ch HiZ

From the manual DIVerse GREEN 1ch HiZ

This passive DI box is designed for galvanic separation and impedance matching of high-impedance audio sources, such as guitar pickups, passive outputs of Hammond keyboards and so on. Internal ratio of 5:1 or 10:1 guarantees the option of running long cable connections or using low-impedance input signal without any loss of quality (dynamics and frequency response). The DI box is equipped with parallel inputs to route the input signal to another device. For instruments with active pickups, active electronics and stomp-boxes, the DIVerse 1ch with output ratio of 1:1 is more suitable.  In case of extremely long signal runs for connecting to low-impedance signal sources, the DIVerse 1ch is allows you to internally change the output transformer ratio to 10:1, with the corresponding 6dB of attenuation. For signal processing, the state-of-the-art Lundahl LL1935 transformer is employed.

DI Box OteCables DIVerse GREEN 1ch HiZ

Don't even ask about how my home-made DI box stacked up in the test against the DIVerse HiZ. The Otecables DI box is clearly a top-class device, and the only little gripe I have with it (besides what has already been mentioned above) is that it should be more clearly stated in the manual which transformer output ratio is the default. This could also be remedied by a toggle switch that can be operated without removing the chassis. For the sake of accurate testing, I had to get my hands dirty and go inside. On the other hand, I understand that for a regular user, this is not a huge deal.

Comparative “measurements”

Right from the start, I would like to explain the quotation marks around the word measurements. I by any means do not posses the necessary technology to dispute the data stated by the manufacturer, nor do I have any reason to do so. Because when testing such high-quality devices as Lundahl or Jensen, the biggest bottleneck for accuracy will probably be my audio interface, please take my findings with a grain of salt. The important word is not measurement, it's comparative. However the quality of my interface, the good thing is that the conditions for all the measured subjects were identical, so comparing the measurements makes at least some sense. Why am I writing this? Basically for no good reason, because both the JDI and DIVerse produced practically identical results. If you look at the included graphs, carefully look at the scale of the image and take note of how small the differences really are. The measurement was performed with signal level of 2,67V, because I simply cannot get any more out of my interface.

Just to be concise, let's add that the JDI uses a Jensen transformer shielded by a permalloy dome, Twin ISO uses a different model Jensen without the permalloy shielding, and the multimedia-focused PRO-AV2 uses a shielded C-tec transformer. At this point, you are probably familiar with the transformers in the DIVerse DI boxes.


Frequency response


Dynamic range




At the end, it is customary to list and ponder all the pros and cons. All of the praises and the few minor grievances I had have been already discussed at length, so let me give you a little summary. Otecables DIVerse are probably the most trustworthy DI boxes I've ever used, and can be compared without any hesitation to  long-time industry leaders, and in some respects even outperform them. If I forgive the little things, like soft screws, sometimes insufficient labels and weight, there is only one more possible issue: the price. 7,115CZK including VAT for single-channel passive DI-box is not cheap and for many sound engineers, this is not a price they will be willing to pay. However, if I compare it to Radial JDI stereo with the official price of 10,207CZK to the DIVerse 2ch at “mere” 10,043 CZK, it is clear that if you are looking for quality and don't care for the rider-friendly brand name, buying the DI box made in the Moravian metropolis is an altogether great investment. I also heard through the grapevine that OteCables offer discounts from time to time, so if you are yearning for a DIVerse and you are not in a hurry, you might get lucky at some point. Simply put, you already know what the DIVerse is about, and my work ends here. The rest is up to you.

PS: If you are wondering why the title of the third paragraph nonsensically refers to “the diversity of divine verses”, let me give you a little hint. An important man in the company, Filip Otevrel, MD. (yes, you guessed it, this is where the letters “Ote” came from) lives in a world where Latin language is his daily bread. The name DIVerse clearly came from his mind, and I think it is pretty spot-on.

Jan R. Šafařík  -  Soundman.cz 

... the original article was published on the portal



Back when I was reading reviews in print magazines, I always thought it's a pity that the manufacturer does not get to respond to the review of their product. In print, this is not possible, but it is possible online. This is why I am happy to forward the reply I got from Filip Otevrel at Otecables:

Right at the start I have to honestly confess that the state of our documentation is – as you rightfully insinuate – catastrophic. There was simply not enough time. But now, when the rental business came to a halt, we've put all of our energy into it and we're working on multilingual website with manuals, datasheets (including weight), photos and a blog were people could ask us about anything they want to know.

  • The diversity of the divine verses – yes, you cleverly discovered the wordplay on DI(direct insertion) in the word diverse, denoting dissimilarity, art, music, poetry and so on. I have to say, the divine part is new even to me, I did not think of that.

  • When you talk about “armor”, that is a nice description of the book-like chassis of the DIVerse. We make them (similar to Radial) from 2mm thick steel plates. The other 0,3 mm could be attributed to Komaxit, which normally adds about 0,1 mm to the material, in this case maybe a little bit more.

  • When it comes to weight, I am afraid it is probably due to the weight of the transformers themselves, metal connectors that we used etc. It is a trade-off that we think most customers will, at the end of the day, appreciate.

  • The initials “K.S.” refer to our electric circuit designer and audio transformer aficionado, Karel Stouda from Prague. We are proud to have him as our colleague.

  • The screw sockets on the sides of the chassis are mainly for fastening the DI boxes together. If you put 6 DIVerse boxes in line, they can be installed into a 19' rack, taking up 1,2U of rack space, which can be helpful for example when routing keyboards

  • Input and output connectors made by Neutrik NC3F/MDM3-H-B (along with their vertically installed siblings with appendage V-B) are in all of our products. The price is higher, but the metal part of the jack can be mounted directly to the chassis, they can be disassembled (they allow changing the PCB without unscrewing them) and the inside part of the connector can be attached to the PCB by a screw. We consider this the ultimate design solution. Also, one more little detail: if someone doesn't like the accidental disconnect protection on the female jacks, it can be taken out)

  • The 6,3mm output jack on the back with the accidental disconnect protection is Neutrik NJ3FP6C-B, and, unlike the parallel inputs on the front (Cliff connectors), gives you the signal behind the transformer, so the musician can enjoy the same “tube sound” that the sound person hears through their PA. You could easily say “transformer sound”, because high-quality tube amps use high-quality transformers that have a great impact on the sound. Typically, they introduce soft-clipping of the lower frequencies with a few upper harmonic frequencies which reinforce the fundamental and color it with aliquots. The same logic applies to DI boxes, only the highest-quality transformers will give us a linear transmission and when overloaded (except the red one, good luck trying to overload that) they produce the soft harmonic saturation that the musicians and listeners desire. This, however, comes with the higher price and weight.

  • The soft screws are a problem and we're working on fixing that.

  • With the labels, we wanted to stick to industrial minimalism, which sometimes means they will be a little more vague. For example, on the front side of the blue and green DI boxes, there is also a thru parallel input on the front panel. We want to hear feedback from more users, and we are prepared to react and change the design accordingly.

  • There is a similar story to the internal switching of transformer output ratio. We basically considered this an expert feature, through which the user can adapt the DI box to their particular needs (for example when rack-mounting the DI boxes, which means they have to unscrew the chassis anyway) which mitigates the risk of accidentally changing an essential setting of the DI box, similar to a polarity reverse function you mentioned. However, if there is an immediate demand for this function, I think we can make it work. This is definitely worth the effort.