Once again, thanks everyone for your suggestions and for taking the time to go into detail - this kind of knowledge is really useful. Jonesy and Jan make an interesting point about interface drivers - I hadn't considered that. I have a Zoom UAC-2 which works like a dream with Win7 and Sonar X1 giving me virtually zero latency. But the big question is whether it has Win10 drivers available - I'll certainly do some research on this.
 
Thanks again guys - excellent forum support from you all and very much appreciated
ji