@dill +1
@ecrotty Unfortunately this situation isn't so straightforward, as it should be. RFI, including FM signals often find their way into low level analog signals in phono stages. Your hiss could be from unoptimized gain or load setting as Dill mentiioned. But it could also be from your analog system acting as a low level antenna and pulling in RFI or simiilar. Grounding can impact it too.
Then if those issues are eliminated as the cause, yeah, maybe the Rega is noisier than you'd like. Borrowing a better phono stage would go a long way to narrowing things down. OTOH, if you bought from a local dealer or have a friend with a turntable, you could try bringing the Rega to them and seeing if you still hear the same issue.
I'd suggest those other potential causes first, and consider the upgrade after. Cheers,
Spencer