I which to purchase a DAC to sit between my ZP90 and amplifier. The ZP90 has opitical, coax and usb outs. Which connection do people recommend - What are the advantages of each? What would be a sensible amonut of money to spent on connecting cables? I will probably go for a DACmagic or beresford Caiman. Do people think that this £200 well spent? Would I also notice an improvement if i connect my Arcam alpha one CDP to either of these DAC's? Is it correct that arcam are about to bring out a DAC.