I'm afraid that the actual answer may make the whole subject seem more complicated rather than clarify it... but here goes...
1.
The Little Ego (and the Little Ego+) use a Texas Instruments PCM5141 DAC chip.
The Big Ego (and the Big Ego+) use a Texas Instruments PCM5142 DAC chip.
Both of those DAC chips have "32 bit resolution".
This means that, in terms of things like linearity, and distortion, they are "32 bit DAC chips".
(They can actually "play 32 bit signals".)
2.
In digital audio...
- a 24 bit digital audio signal has a theoretical dynamic range limit of 144 dB.
- a 32 bit digital audio signal has a theoretical dynamic range of 192 dB.
3.
Both 32 bit float and 64 bit float are used internally by many digital audio editors, and are sometimes used to save files for editing.
(The reason is that doing so offers a massive amount of extra dynamic range which might be useful when applying major level changes and other effects in edit.)
As far as we know nobody is distributing 32 bit files for download (and, unless the dynamic range of those files exceeded 144 dB, there would be no practical benefit to doing so).
4.
The audio systems in various operating systems, like Windows, have internal limitations in terms of audio signal bit depth.
Third party USB audio drivers also have their own specific limitations - which may vary depending on other things.
Player programs also have their own internal limitations - which are often unspecified.
So the bottom line is this...
- The DAC CHIPS in both the Big Ego+ and Little Ego+ are capable of 32 bits of resolution (so, for considering things like linearity, and distortion).
- In theory it should be possible to send a 32 bit audio signal through from a source device to the DAC.
- We did actually have a confirmation that our Ego DACs were capable of playing 32 bit audio signals... but I don't know what operating system or signal source was used.
- We have no way to source such a signal, and no way to actually confirm that it is reaching the DAC as a 32 bit signal, so no practical way to confirm this.
(Therefore, whether your source, or your operating system, is able to do so, or will accurately report what it's doing, is anybody's guess.)
- Even assuming that a 32 bit signal would "make it through the software" the dynamic range of a 24 bit signal exceeds the dynamic range of the DAC hardware itself.
(So there would be no practical benefit to be had from the extra theoretical dynamic range of a 32 bit signal.)
And, of course, taking a 24 bit audio file, and "upscaling it to 32 bits so you can send it to a 32 bit DAC" would offer dubious benefits - at best.
So the less-than perfectly-clear answer is:
- as far as we know yes (32 bits)
- we have no way to actually confirm this
- it really doesn't matter because there is no practical benefit to 32 bits over 24 bits anyway
Both BIG EGO+ and LITTLE EGO+ has "Precision 24/384 USB DAC" written on them but the specs mention 32bits under "Bit Depths Supported".
Can I get some clarification on this, please? 
