Hi Stan,

Thanks for you message. I've just had a chat with another hi-fi geek at work and he suspects that it might be jitter from my poor spdif sources, an old slimdevices squeezebox or my asus motherboard. I'm going to try out a m2tech hiface 2 and see if I get a better sound with that. It does seem to be male vocals that were the problem. I was listening to blur parklife when I noticed it most.