computer sampling into the 3000

Hi all - just got a 3000 today!! woooo, loving it so far. Have used the classic and xl in the past and jsut recently my classic died on me so i got a steal on a 3k and am loving it so far. Sampling question though that really doesnt have much to do with the 3k itself, heres the deal - hopefully someone can help out

Sampling from records, works perfectly fine, always has with my MPCs, I recently got a computer that I can use for tracking, editing and am running into a little problem with my first go at going from PC>MPC. Ive got a Presonus USB audiobox and am running the outs of that into the ins on the 3000. When i have cubase up and running and play a piano riff or something into the MP, the sample records - yet there is a HIGH FREQ hiss over top of the whole thing. In fact that hiss is there even if i try and record chops that i have done in goldwave/recycle. Any idea what the deal is? Ive tried messing with the record in levels and its always there, cant filter it completely out either. Im probably missing something completely. Anyone help out?!

Thanks

If sampling records is fine - I would wager its noise in your signal from the Presonus. I read it has balanced outputs but perhaps there is a mismatch in impedance causing this. Is the sound from the Presonus also hissy? That is, without going into the MPC? Also, what is your gain staging like? Though you mention having experimented with different levels, if you are whacking the Presonus up and keeping the gain on the MPC slightly low, you may be introducing more of the noisefloor into the recording. I don't think the MPC ADC can be at fault here as you state sampling from records is fine.