The Antelope Audio Zodiac Gold has been a favourite of ours for a year or so now. The new Zodiac Platinum (packaged with the new Voltikus power supply for £4,250) sets a whole new standard of performance, and features.
As well as incorporating highly effective upsampling of multibit data, the Platinum enables decoding of DSD. Antelope also tackle the inherent noise issue with DSD by incorporation of upsampling of this signal, enabling much gentler filtering of the analogue signal.