Roland tr-8 using multiple audio outs via USB in Cubase 7.5

Ah gotcha.

G-string - yes i do for the last three years. No problem whatsoever. Currently running RME MADI FX with real 32x IO (Ferrofish MKII two of them chained 32ch on 96khz), plenty of internal VSTi, NI, U-he, outboard gear (RS7000, mc 909, synths and fx) everything fine no problem here