LP/SP filter vs. Mother-32

[soundxplorer]

Anyone have both to compare? Should the lowpass filters be pretty much the same?
I used to have a Little Phatty that I loved, and I'm considering a Slim Phatty now to get that sound again.

I do have a Mother-32 which sounds great, but one thing that bugs me is processing external audio through the filter. I guess because it was intended to be compatible with Eurorack the external audio needs to be boosted quite a bit with a preamp before going into the Mother. I don't remember this being the case with my old LP, can anyone confirm? i.e. Can you more easily plug line-level things into the LP/SP?

[bichuelo]

The Slim Phatty and Little Phatty have exactly the same synthesizer audio engine

Indeed, the audio input of the Slim/Little Phatty does not need any boost like the Mother-32 does