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.
FWIW, the sound guy says he gets a very low signal from the TM60 as well (I've been using that lately, going XLR out -> FOH), which I thought was very odd. I think that's a separate question really, but figured I would mention it.