DI inputs 0VU level was set to -18, so you can compare the relative outputs of the different DI’s from the amount above or below -18. (DI’s from interfaces and channel strips not included). For the TL;DR, again, the old myth “You get what you pay for”, soundly busted. Like so many other facets of modern life, once you get into the reasonable range, price and performance seem to be completely uncorrelated.
You get what you pay for?
40 dollar vs 200 dollar vs 300 dollar DI’s head to head. No doubt the Apologetics will fly and there will be numerous God of the Gaps claims, but until someone tells me how to measure “unobtanium”, “warmth”, “dimension”, and other nonsense religious terms, here is the reaity based version of it:
ART Dual MP DI – Talk about having to zoom out to see the frequency deviations! Youch. Not sure if this was a screwy unit or if this is really indicative of this unit’s performance.
ART Phantom 1
-10dBFS – The highest output DI Box I have tested so far
Countryman Type 85
-12dBFS – An active DI box with a very flat frequency response, decently low noise and very low distortion
Focusrite 18i20 Gen 2 – Interface DI’s are terrible right? Right??? Well, this one is for all intents and purposes ruler flat, and has noise and distortion specs which should be inaudible in any real world use. There may be better DI’s, but trying to blame your lack of a hit on this particular DI would be time better spent on self reflection
Focusrite Octopre MK II
An extremely flat, extremely low noise and extremely low distortion DI. Surprised at the performance here!
IK Multimedia iRig HD2
As screwy as the frequency response is, its actually within a pretty narrow range, and zoomed all the way in. On the other hand, the ripples sure look like phase issues! No ASIO driver.
Maudio Fast Track USB – One of the first USB audio interfaces. Quite ancient, surprisingly flat, but not so good on the noise end.
-18dBFS – Based on the ancient Jensen Direct Box transformer application notes, this is a modern version of the same circuit you would likely have used if you recorded with us at Vintage Recorders. Heard on countless classic albums and probably tons of modern ones in this form. Extremely good performance in all areas: noise, distortion and frequency response. I am always very skeptical about gear which has a lot of hype running around it (and as shown in so many of these charts, for good reason!) but this DI box deserves every bit of praise it gets.
Radial Pro AV2
-18dBFS – Strangely, extremely similar specs to the Radial JDI. At this measurement resolution, it is actually hard to tell these two apart, with the ProAV2 possible having better distortion specs than even the JDI. At the moment, this is 30 dollars cheaper than the JDI at Sweetwater, and with the AV2 you get TWO DI’s rather than one…less money, twice the DI’s, extremely similar performance.
Radial Pro D2
-18dBFS again, like the Pro AV2, extremely similar performance to the Radial JDI, and in this case, another ten dollars cheaper! Like the Pro AV2, the only obvious downside I see for at least DI applications, are the plastic jacks and nuts.
Radial Pro DI
-24dBFS – Not as you might expect, half of a Radial Pro D2, this unit has a lower output and reflects this in noise and distortion specs. Still, it is extremely flat, and the noise and distortion are not likely to be audible in normal studio use.
-12dBFS – Not a DI, but just in case you wanted to see just what these things do.
-12dBFS – I don’t really know what to say here, not just my love for the Jensen Direct box, or the less than 50 dollars I think these things cost, specs wise, this el-cheapo DI box dominates this category of devices. Lower noise, distortion and just as flat as the Radial JDI. I think this is one of those cases where confirmation bias and magical thinking are going to do their best to make us deny the performance of this budget, yet amazing piece of gear. There are other features that you may want that the Radial JDI provides and this does not, but lets be honest, this cheap box will not stop a great performance, and as far as I can tell, it would actually be better than most (all?) I tested.
Sonoma Wire Works GuitarJack Stage
Mainly mean as an iOS device, though it has ASIO drivers. Another one where the frequency response had to be zoomed out to fit the deviation. Used for its intended purpose, this is quite and awesome, ergonomic, and convenient device. As a studio DI? Maybe if you want that “character” shown in the THD measurements I guess.
Sonoma Wire Works StudioJack Mini
UK Sound 1173 – Another DI that needed to be zoomed out in order to see the deviations in the frequency spectrum (see a pattern with the “vintage” stuff?)
UREI 325 -24dBFS, the lowest output DI so far in this test. In the case of this DI, the frequency spectrum had to be zoomed out a bit to fit the variations in frequency response
Waves PRS GTR
Waves products are always a crapshoot – Sometimes they put out something great, often they’re duds or worse. In the case of this DI, not only is the performance bad, but it cannot be phantom powered.