Let me guess... you asked this even without opening the Preferences window.
That's not how you're going to learn about FB2K.
Go read through every single dialog box and instruction; supplement what you don't know using the FB2K wiki, which is linked from the front page of HA.org.
Furthermore, this question has been asked many times, hence I recommend you use the Search function.
Only after doing these 2 things, and you're still clueless, then it is all in your right to ask.
Anyway, it's 24/96.
CD-music is indeed sampled at 16/44.1, but if you have ripped your CDs to a lossy format like mp3, ogg vorbis or musepack, well, these files do not have bit-depth per se (I'm not familiar with this subject though).
To change your bit-depth, go to the Playback dialog in Preferences. To resample your files, you have to get the standard DSP array from
here. Then go to the DSP dialog in Preferences, activate the Resampler DSP, then go to the Resampler dialog to modify the samplerate.
Do not activate slow mode.
I cannot advise you as to the sample rate you must set, because I don't know what to do on the A2 ZS.
Make sure to disable EAX and all other effects, and disable calibration, or set basic calibration only (there may be more to do, but again I'm also clueless). Otherwise, the A2 ZS will not play at 24/96.