[noggin]

Receiver confirms that it is really  like example 96 kHz  or 192kHz sample rate, but when we talk about bit depths it is not clear : is it 16bit or 24bit...
What is possibility to check bit depths output on vero 4K ? 

All Amlogic devices are limited to 16-bit output. An HDMI analyzer or a HDFury Vertex will show you the maximum word length (bit depth) set in the Channel Status Bits of the HDMI signal. 24-bit doesn't necessarily mean that the output is indeed 24-bit, but these bits are set to 16-bit, 24-bit output is completely ruled out and that is what you would see with Amlogic devices.

I have a post somewhere on LibreELEC forums on this topic. I recorded the HDMI output at 24-bit depth and then analyzed the real bit-depth of the output. It is only 16-bit for Amlogic devices.

Use your ears :-)

Yes, this is the cheaper way to test the audio bit depth and sampling rate. 

 So presumably whilst Dolby True HD and DTS HD Master Audio output WILL be 24 bit from these devices if bitstreamed, PCM is limited to 16 bit - so on-board decoding of 24-bit FLAC stuff will be limited to 16-bit output?