I have a RME Fireface 802 audio interface and with Totalmix FX I can select the output level at +4dBu or -10dBV. Which is the best input level for the Eventide Space?
Probably either, as long as you set the Line switch on the Space appropriately. Can't give a definite answer as these level numbers are usually nominal, and it is hard to know what the actual levels are. -10dBu is probably safer.