Quote Originally Posted by markb
You're feeding a passive DI box designed for line levels =~1V with an instrument signal much lower. Some kind of preamp would be useful, maybe your GT2 would get the levels up. Either of your multi effects would handle it but you'd need to use the headphone output on the ME50 or crank the output level on the Digitech if you use those. Plugging into a high impedance input just gets you into problems of signal loss unless you're using short cables.
Hmm. My current idea is to use the Behringer headphone amp as a booster before the DI box to give it a little more juice, maybe even taking one of the other headphone channels as a personal monitor, provided I can still hear the band mix from the monitors. I have been using the GT2 before the DI box as my 'amp in a box', but everything on that had to be absolutely cranked to get the signal within normal operating ranges in the mixer.

I think you are addressing my real question here, which is how voltages and signal strength are related. My understanding of line level was that it had mostly to do with a low impedance signal, but I did a brief search after I read this and it seems like there is a 1V reference voltage for line level, so I see your point. I take it a preamp serves to mostly increase the voltage then?

One last point/question: I thought a DI box was more or less a transformer, which I thought was really just a voltage changer. Why must voltage be addressed separately before the DI box?

Thanks for all of the info.