Shindo makes some very good sounding tube gear, albeit, at a fairly stiff price. I think that a good competitive alternative would be Audio Note (uk) gear. They have a wide range of options and prices. The lower price models are quite a decent bargain for the sound they deliver, the pricier stuff being better, but not nearly as good a bargain. Like the Shindo gear, Audio Note's phono stages have only enough gain for moving magnet cartridges and are meant to be used with a step up transformer. As a broad statement, I would say these two brands have a similar sound (which I like).
Whether or not any alternative would sound better to you, would be purely a guess. There really isn't a "tube sound;" the differences in sound between high end tube gear is, to me, much greater than the differences between comparably priced solid state gear.
Given that the Devores are quite efficient and easy to drive, you have the advantage of being able to use low-powered amps. To me, low-powered tube gear sounds much better than higher-powered stuff. I find the O/96 to be a little on the "polite" side and not as lively sounding as I would like. That might mean that they could use the kind of "kick" that an output transformer-less (OTL) amp can deliver. While I have not heard the O/96 with such an amp, it might be worthwhile looking into the lower-powered Atmasphere OTL amp and their very good linestage.