Thanks to all your words of wisdom I've decided against changing the Rotel improvised preamp and going for a new dac. I've looked at the Beresford Caimen and the Cambridge DACMADIC 100 and the MAGIC 100 Plus. The later uses upsampling, which I'm suspicious of, and the other Cambridge only plays up to 96kHz files, so I'm leaning towards the Beresford. Anyone got experience of any of these dacs?
John