does anybody know if an adc-20 can work between my at-3035s and jb3? i just bought it and seem to be a bit confused and think i may have made a mistake
You need a pre-amp to provide gain & phantom power.
If if have or add one of those, you'll still need a converter to transform the AES (XLR) from the adc-20 to optical.
The Hosa ODL-312 will do the job quite nicely.
http://www.hosatech.com/hosa/products/odl-312.html