DI question

[AsgardFrank]

Hi guys, i'm looking after a di box but i'm quite confused:
i own a rme babyface (470 kohm impedance) and i'm using it for gtr/bass recording, vst processing (tse, lepou) etc.

Countryman 85 has a 10 MOhm input impedance while Radial j48 has only 220kohm, would you please explain me how does that work?
I know i need a hi impedance input, but here the radial's one is even lower than my rme instrument input.

Thank you

 

[AsgardFrank]

Anyone can help?

 

[deLuther]

Standard tube amp have 1 MOhm input impedance, tube screamers usually have 510 kOhm.
Lower impedance means less highs, but, in case of passive DI boxes due to transformer inductance highs can at good level (impedance due to inductance increases with frequency), while impedance in specifications not high. Usually mentioned impedance measured at 1 kHz.
Impedance higher than 1 MOhm gives even more highs, but this can be not too realistic compared to amp

 

[AsgardFrank]

Hi and thank you for you answer.

I think i understood what you mean, but what do i need then?
I knew i needed an active di since most of my guitars have passive pickups.
Countryman is not easy to find here and it would be anyway quite expensive.
For example i would be able to find a bss ar133 (1 mohm i.i.) at a really good price or, since a friend of mine is in the us right now, i could afford a radial j48 for 199$, but he's leaving in a few days so i have to decide quickly!

What do you think?

Thank you

 

[deLuther]

ar133 is good choice, but it can not hold large guitar levels (pad also reduces impedance to much lower value), if you have hot passive pickup you should consider something other (countrymans also have not large input levels and with significant distortion: 6 V peak to peak with 1% THD for Type 10, Type 85 have even lower level: 5 Vpp@1% THD). J48 claims to have big enough input level (even for active electronics at 18 V).

Russians just have other alternative to this DI boxes - microphone/instrument preamp Digilab SPM-100, works at least as good as AR133 (compared personally) and handles up to 16 V peak to peak with THD less than 0.1 %
(and slightly cheaper)

Not only impedance should be considered, but input levels as well.

 

[AsgardFrank]

Hi and thank you, i think i got the point.
I do have to decide in a couple of hours so, again, i'm asking your opinion:
since radial j48 input impedance is lower, would i have a lack of dynamic compared to the bss 133 (ii 1 mohm) beside highs?
I do really want a good sound for reamping too