I just tested 29 DI Boxes and...

[Mr_-G-]

I believe you when you say you hear differences, but to me that is not sufficient as we are all subject to the "placebo effect".
A scientific approach should reveal differences when they exist, without being subjective (i.e. you hear, but I don't type of argument) and (more importantly!) would also help understanding if those effects are above perceptual thresholds. Wouldn't that be informative and desirable?
The video linked above shows a scientific (i.e. non-subjective) approach to find answers to these questions. It also shows towards the end how parties interested in selling 'magic cables' are much against this kind of evidence.

[Elias]

DI boxes and cables are really a tool as far as I understand. This means that contrary to a guitar amp, it's much less about how good it sounds, and much more about what it does to the signal. Of course they affect the sound (because they affect the signal), and while that is relevant, it's not what DI boxes are about. This is why a scientific analysis would be more useful universally. Especially to combat unjustified marketing (like @Mr_-G- wrote)

[Hlaalu]

This might be my hobbyist psychology, but I feel like people respond to reported differences (about anything) in two ways:

1. If the reported difference is "felt" as such, they say what one feels is irrelevant because objective, measurable data is needed to make a true comparison.
2. If the reported difference is an objective "measured" data, they say measurements don't matter since what really counts is if and how such differenced are experienced (=felt) in real usage.

As Mr_-G- says, what counts is differences above the perceptual threshold. And they can be measured, but it's neither in terms of "I feel this or that way about X" nor "my spectrum analyzer tells me there are differences so they must be relevant". Rather, one would need to do a blind test with people (or even one person) trying to tell things apart. If they succeed in a consistent and statistically significant way, then there are relevant differences between X and Y. If they fail, then either there are no differences, or such differences are not within our capability to discern them, and thus are irrelevant.

Of course, there's also the case in which knowing that X is measured to be better than Y makes me liking it more and willing to spend a lot of money on it, even when it's incontrovertibly established that the difference between X and Y is well below the perceptual threshold...

[Kevinology]

What do you mean by customised at the j48 radial??

It is customized by modifier in Korea. He changed the transformer and some parts!

[Kevinology]

Guys, take it easy. I won't write down my personal opinion. As I mentioned in the last post, I think It's about taste, not good and bad.
But if you want to persist in your opinion, I want you to do a phase inversion test at DAW and ananlyze the EQ graph. There is an exact difference between each DI.
I just posted this because I wish all of you to find your best DI
have a good day, everyone!

[Elias]

a scientific analysis would be more useful universally

To contradict/clarify this earlier statement:
We are ultimately here to make music, right? So whatever helps with that, go for it. Data like these audio files is an awesome resource regardless.

[DavidSydney]

Hi all,
Nice work with all the testing Kevin, but I really think you should review your rather hysterical and absolutely incorrect statement about connecting to an audio interface without a DI.
I've just checked the specs on your interface to confirm there is absolutely no 'impedance mismatch' between the Nord's output and your interface's input.

I'm not sure where this idea has come from. Perhaps from a misinterpretation of the importance of impedance matching in radio frequency and digital connections. These are very different signals from audio and the same rules don't apply.

What you're asserting is just plain wrong. And listening to your 'WODI' recording against one of the DIs, I can't hear anything 'wrong' with the file.

By all means choose a DI that you like the sound and facilities of. But for playing into an interface, or any sort of solo playing, you just don't need one. And really, if one is needed or wanted by audio techs at a show (for their own reasons), they'll usually provide it.

Don't take my word for it. Please go and check some independent technical references discussing audio impedances. Somewhere like Sound on Sound is a good place.

Sorry to sound a negative note, because you've clearly done a lot of work, but there's a misunderstanding that I think should be corrected.

Hope this is helpful.

David

[Elias]

Nice work with all the testing Kevin...
...Sorry to sound a negative note...

Sounds about right to me as well.

A DI box will also make the signal balanced, which is relevant when distances are long and the outputs on Nords are unbalanced. So probably not relevant in a studio setting. However, the unbal-bal-unbal conversion might change the sound (like anything in a signal chain can).

EDIT: Also thank you for being respectful David.