the op has really no way to know but to get both and try in his own system
short of that, he is asking for input
i have not heard a freya in my own system, but i have in others... but of course, not A/Bed against an sp15
i would say that so long as the unit is in good shape and checked out, no caps or tubes failing etc etc, the sp15 is one of the units that audio research built its name and reputation on in the 90’s, designed and built to take on all comers ... at the time it was its main linestage under the megabuck reference one ...
you can bet this preamp, while no doubt having its sound signature, makes absolutely no apologies to the linestages on the market today in the 2 grand price range
