I just bought 5 second hand Behringer DI 100 DI boxes, so I decided to test them, and they all performed pretty much the same. About the same amount of noise floor and pretty similar amount of THD distortion. While I was at it, I decided to test all of my DI boxes, and surprisingly – Other than the H&K (that has a cabinet simulation that can’t be bypassed) and Behringer DI20 (that was REALLY noisy), they performed pretty similarly.
Output levels were drastically different. I fed the DI boxes -18 dB level sine wave thru a reamp box to simulate guitar impedance and had the microphone preamp gain at zero. The DI boxes returned these values:
-10.8 dB – Radial J48
-15.1 dB – Behringer DI100
-17.0 dB – Behringer DI20
-21.0 dB – Sansamp BDDI
-34.6 dB – MXR Bass DI+
-36.7 dB – Hugnes & Kettner Red Box Classic
-40.6 dB – Radial Pro D2 (passive DI)
And naturally you can compensate for this difference with the preamp, so most of the time, it’s not a problem. If you have a really loud source, using a passive box such as the last three will help a bit, when with most sources, an active DI box will do the job. But do notice that the DI20 is not THAT noisy by default, but if you engage either of the pads, the noise levels go thru the roof. But it’s the only DI box from these in addition to the Red Box, that I would not recommend to use for capturing guitar or bass DI tracks.
edit: I just realized I took all these screenshots with 4.5dB/oct slope in SPAN so it seems like my interface (M-Audio ProFire 2626) has immense amount of noise even tho that is not the case. Here is a comparison of Radial J48 with 0 dB/oct slope:
Radial Pro D2:
Behringer DI 100 (note: harmonic distortion levels are at -87dB, -82, -113 and -106 dB)
Behringer DI 20:
with the -40dB pad on, we can see that the noise floor stays at the same level but the level dropped by 40dB, thus the signal to noise ratio got significantly worse:
Tech 21 Sansamp Bass Driver DI:
and BDDI with the XLR pad turned on:
MXR Bass D.I.+ M80:
Hughes & Kettner Red Box Classic:
And the cabinet simulators looked like this:
What about the sound?
And for the sound… Well, listen to yourself. I put both the clean tone and the distorted tone to the same clip. The clean is on the left and the distorted on the right. Same DI and settings used. No noisegate on the distorted channel so you can hear the difference in the noise floor. I used a single coil telecaster with new strings, so the noise sounds a bit different because I couldn’t find 100% the same position. First is J48, then SansAmp BDDI. So for the sake of capturing the DI track, I would be happy to get it from any of the aforementioned DI-boxes, except the Behringer DI20.
Any questions or comments? write them down below.