How can I tell if I need a better clock for my DAC?

Here's an article that touches om the subject even though ge talks more about usb inputs. He also has a list of components he recomends, including dacs.
https://darko.audio/2013/07/when-should-you-use-an-external-usb-spdif-converter/

I suspect a lot of new dacs sound better than your Cambridge but it doesn't have to do with just jitter.

Seems like even a dCs dac gets better with a better clock. Better clocks and cleaner power can probably help almost any dac.

https://forum.audiogon.com/discussions/dcs-puccini-clock