I have 2 Cambridge units. OneI use as a transport into my external DAC, a Bryston DAC3. The other sits in a midfi system and I use the internal DAC.
Obviously I ‘m a CA fan, and @oddiofyi suggestion is the way I would go,. OP has stated in the past that enjoys his CA streamer, so I’m not sure why he has now become dissatisfied , but if he is using the internal DAC I think he should notice an improvement with using a better external DAC