I put them in a Continuum 500 (same circuit as Capri according to Jeff Rowland) and I burned it in for 80-hours before really listening a lot. I did try it for an hour or so before burn in. When I finished burn in there was no earth shattering difference. It sounded good before and it sounded good after.
BTW, I've got a little reverse RIAA circuit which I put between a CD player and the phono stage to lower the gain and present a cartridge-like signal to the phono stage for burn in. I loan it out to friends in the Denver area for such things. Anyway, I don't think the Capri's circuit really needs much burn in.
Dave