I'd never use a digital pre. The Ayre's digital pre is about as good as I've heard and it's still not even close to using the pre on my AX5/20. I've had the Dave in my own system a couple of times and I've listened with borrowed LCD3's and the top Hifiman can's (don't love them like so many do). I like the headphone amp on the Ayre much better. It's just a more coherent sound than the Dave IRT to the bass. I've spoken to a couple of DAC designers now and they feel the same way. I love the Totaldac and if it was money no object and I had a set of Vandersteen 7's with reference amps/pre, then I'd get the Totaldac that is twice the price of the Ayre and much more expensive than the Dave. Again, I think it's a great product and whoever owns one will love it for a long time, but to ME, the Ayre gives me similar great mids and highs along with deeper and just as musical bass. I could have afforded the Dave and that's why it was in the house. It has a certain charm about it that most other just done. Honestly, I like the Ayre, TotalDac, Dave, Trinity ref and a few others better than I like the Rossini. The Rossini to me, like all the DCS DAC's are a tad dry. Accurate as heck and excellent DAC's (better be for that money), but they are not as musical to MY EARS as a Dave or QX5/20 or TotalDac. I know that I"m not the only one who feels this way either.
JMHO