naim uniti star & griffin diablo 300

Can I run the uniti star through my griffin diablo 300 amp that doesnt have a dac installed.

You can, although the Uniti Star doesn’t have a line-out, just a pre-out, so you would be going through the Unit Star’s pre-amp and volume control.

If it’s just a. temporary thing, then probably fine, but long term you’d be better off with a dedicated source such as NDX2 or ND555.