Another thought, you probably need a mic pre-amp to go into the line level input.
If my other advice does not work. Another option is to buy a XLR to female TRS converter (or make your own
) and use the mic input on the 11 rack (
http://www.amazon.com/TRS-Female-XLR-Male-Adapter/dp/B0024X7XL0).
This is probably the best option as it will allow better control over the signal (pad/gain).