Passive pre with class ''D'' power amps, issues ??

If I read the specs on it correctly the input impedance is high enough to work with most passives, but I'd be a little concerned about the gain (27db) and sensitivity (3V rms to full output). Typically something in the area of 1V would be ideal. However, this also depends on the source driving the passive. Most digital sources are 2V but some are higher. You could try a couple and see what happens.

You'll improve your odds of success with something like the Sonic Euphoria, which controls attenuation via multiple transformer taps rather than resistors. With no AC input it can provide (depending on the configuration you specify) anything from 2 to 10dB gain IIRC. As these things go it's pretty reasonably priced as well.

I would join Jonnyb53 with his recommendation. If to use passive preamp then transformer based. I have had good experience with Promethius (spelling...) Ref 3. It was much better (and cheaper) then famed Placette

Still, I wish to point out that not a singke passive preamp was as good as high quality active preamps (I use tubed ones only) not inresoultion and detail - despite many testimonials and never ever dynamic range and bass extension.

Good Luck