DI quick question

[dalley]

Just wanted to know if there is any difference between:

A) Plugging directly into a DI input on a mic preamp that has one
B) Plugging into a standard passive DI box, which is plugged into a mic input on a preamp

I am asking this because some of the mic pres I am considering (DAV BG-1, Sytek) do not have DI inputs (which I want to use for bass, synth, etc)

Thanks

 

[Rodger Hartlett]

yes there is a difference. with a passive DI you would be going through an impedance matching transformer so you would be getting some transformer coloration in your signal. this would be more apparent the hotter the signal is as the transformer would start to saturate especially in the lower frequencies.
transformers (unless they are very expensive ) may also tend to roll off the very upper frequencies but this may not be immediately obvious.
a high impedance DI input is preferable for keyboards to maintain proper bandwidth but for bass and guitar the transformers might actually take off the harsh edge and sound more musical.