Hey beowulf, not a dumb question at all; if you love the SQ of that DAC, one possible way to improve its performance is with something like the Audiophileo, or a Halide Bridge or other "async-USB-in-a-box" device. Depending on your DAC, and your computer/software combo's ability to deliver bit-perfect [pretty sure you use foobar, right?], then the $ for an async USB device could be worthwhile. They were for me. Of course, those things aren't cheap in their own right, and it may be worth it to spring for a new DAC, depending on your old one and your budget. But to answer your question, I think yes, you need to do something about the fact that right now, your computer is the clock controller for your DAC.

Our forum member who has the Empirical Audio Off Ramp, makes a very good argument for splitting out those functions, so you can keep pace with the techno arms race component by component. I think there is a lot to be said for that. If I was in your spot right now, as I was a couple of years ago, I would look hard at the Off Ramp or the Audiophileo. The flip side of that, is that really good async DACs are available for about the same price. The Mytek 192 for example, is not only async, but also plays DSD, has a headphone amp, is going for $1695. Teac has an async DSD DAC that goes for less than a grand, and has been very well reviewed.

beowulf, if you decide to keep the Rega, I would look at one of the three USB/SPDIF async converters/reclockers I mentioned above: the Halide Bridge, the Audiophileo, or the EA Off Ramp. See if you can get one or more to try out; I think you will be impressed at the difference clock improvement gives you. But in these price ranges...........you have a lot of choices that would give you a newer DAC, with likely improved analog electronics as well.