Hi everyone.

So, not too long ago i got a Behringer UMC22 audio interface, the mic preamps are very good, low noise floor and low latency with the right drivers, all good, but the HI-Z input of it, its not very good.
I found that it was saturating when i picked the strings hard, also it sounded kind of "congested" and dark so i bought the cheapest passive DI Box (my guitar is passive too) i could find and man, it was a BIG difference.

The ohm input impedance of this DI box its 50.000ohm, which compared with other more expensive DI boxes, its quite low... so what? what benefit i would get from a more expensive DI box such as a Radial one?
My guitar already sounds much better and dynamic, but i wonder...

This picture shows the difference of the EQ curves of the guitar DI.
The red EQ is the audio interface and the green is the DI box:

 

Any bypassed guitar pedal will give you the best impedance to "attack" your soundcard.
Just try if you have a pedal, and please tell us.
If you find a used Radial Dragster, it is a great unit, I got one, it makes sound "smoother" or "harsher" when you turn the wheel (passive box) but it is a "soft" action, a pedal is enough to me https://www.thomann.de/fr/tonebone_radial_dragster.htm

 

Gonna give you somewhat a half baked response, from experience, and it's been a long one, connecting guitar directly to the audio interface, whether the hi z option is included or not has been a large hit and miss, especially with passive guitars, i know shit about impedance but what i know is that a DI box will help get you a more "natural sound", and a "fuller" one especially with an amp sim, the thing is there is two types of di Box, passive and active, passive DI box are meant to be used with active guitar pickups, to tame down the gain and volume and bring it down to a balanced volume for your amp sim, active DIs are meant for passive guitars that lacks that very same gain and volume and bring it up to a balanced a somewhat "loud enough" level.

i have used many amps simps, and i have been experimenting with a lot of audio interface from friends and my own, i'm lucky enough that my two Audio interfaces are up to the task, but i do own a passive and active di that i use when the need arise, for exemple a passive DI is mandatory for active bass pickups, and an active DI is really mandatory for most passive "low end" guitar pickups, but as i said in the past, the real secret is in the pickups themselves, if you have a great set of pickups, you're most likely not gonna need a DI (from my own personal experience) if you record a lot of clients a DI box or a set of DIs are really a must, because you never know what type of guitar they're gonna bring with them, pretty sure that those suckers can afford better guitar but they're self centered mfs, so to deal with them you need a set of DI boxes...

 

Passive DI boxes are a transformer, a case, a few passive components and some switches and connectors. However, the cost of switches and connectors can vary depending on their quality and reliability. The case is a cost factor too. You can throw radial box across the room it will survive, while some cheaper products will break while you press a button.

The most expensive part of a passive DI box is normally the transformer.
You can get some Chinese transformers for 1 buck, while the big brands like Jensen or Lundahl tranformer can cost you more than 80 bucks. They all do the same basic job. But the more expensive are better screened, have a wider and flatter frequency response and introduce less distortion. They can deal with high levels without distortion and have a better electrical safety isolation.

In short, cheaper transformers do not perform as well as their expensive counterparts. And most often you can hear this. It is like always - it is the icing on the cake

 

I find that the best DI boxes are from Farnells in the UK and are very cheap:
https://cpc.farnell.com/img-stage-line/dib-100/di-box/dp/DP26026
I use it in a reversed conection to send a line signal out from a Focusrite Scarlet Interface, to reduce the line signal to an instrument level, to feed into an external Boss Gt001 for reamping, and it works a treat. But I dont know how it works in a configuration that its supposed to work in.

 

Loving my Neve RNDI.

 

I will try someday, unfortunately i dont have any pedals with me, but i know someone mentioned once that you get a good signal when bypassing it. However, how much better could it sound? that is the question.

Right, Passive for Active guitar, Active for passive guitar, but this time i am using a passive di box with a passive guitar, and the signal is loud as hell already, at 50% volume it reachs almost 0db. So i wonder if an active di box would be really necessary... guess i will need to try myself someday.

Exactly, the transformer is what makes the difference... so far i am not having undesired noises or distortions, maybe its all stupid marketing and people think that a Jensen transformer is the best thing in the world?! hahaha. Joking, but yeah, what you said its what i thought too.

I dont really care for your super expensive DI Box.