Started to dig around best quality sound source for Columbus (MIB2.5 as far as I am understand):

Investigation of the supported bluetooth codecs just leads me to nowhere as max ACC codec is supported and LDAC is not an option at least now.

Aux is not installed by defaults anymore , but looks like it very easy to retrofit. Connection via AUX will be probably ideal if you do have an external portable DAC or portable HiRes player. And looks like I am going to retrofit one , close to USB in ashtray. 

Another option is Android Auto , which support at least PCM 44.1/16 (CD Audio uncompressed format) via USB. I am not 100% if its supports higher sample rates and 24bit. But both Tidal and Spotify are supported as AA applications and Tidal HiFi giving you 44.1/16 lossless FLAC audio streaming strait in to your Columbus.

And the last but not least playing FLAC  files from SD/USB.  As per manual :

  

 

FLAC up to 96(/24 as I never saw 96/16) supported with stereo and even 5.1 and 7.1 (I am assuming 5.1 and 7.1 will work nicely in the systems with factory installed amplifier). But I always had some   "file with error" message when I tried to play anything higher than 44.1/16. Even 48kHz files did not work for me.  But couple of days ago I decided to get to the bottom of the issue and download sample files from here: http://www.2l.no/hires/. And surprise surprise I got 96/24 FLAC working on my Columbus. And to completely confuse me 192/24 working as well! Not that I really need 192 as I do not hear difference between 96 and 192 but difference between 44.1/16 and 96/24 exists and I can hear difference in the car and in my "proper" more less headphones connected to the SoundBlaster Zx.

 

Which formats and sound streaming services you are using ? 

 

On 14/06/2020 at 01:21, Shahoff said:

I got 96/24 FLAC working on my Columbus.

Cool.

With what did you play the files? And how did you connect it to the Columbus?

 

I have an iPhone and using Tidal to play music. Tidal uses Master and Hi-Fi like you describe. Spotify has a lot of loss in their music.