Recording drums with UR28M

I’d like to record drums and use at least 6 inputs. The UR28M has 2 mic pres. Then I can get we 2 external mic pres and connect them to the 2 line in inputs. How could I use either the 1/8 inch input or the spdif in? Anyone know a simple 2 Channel mic pre w spdif out?

ART DPS II.

Perfect. Thanks!