I've been using ROON for 3.5 years now and the Altitude 32 since February.
The Altitude 32 plays up to 192-24. You can verify this by using the audio mode "Native" and it should play 192-24 or 176-24 fine. However, if there is an issue, or if the playing skips, then there may be an issue with the firewire card, contact [email protected]
, and they will take good care of you. In my case I had the skipping, and Trinnov replaced the firewire card, and all fine thereafter.
Since the Altitude 32 only plays up to 192-24, set ROON to downsample to an even downsampling - DSD (or DXD which is 352-24) or multiples of DSD to 176-24; 384-24 to 192-24; but do not upsample, leave everything 192-24 and below at its native sampling rate (I find that sounds best). You can do this in the ROON DSP menu, which I do because there are some DSP filters that can only be engaged in the DSP section.
Now Auro-3D by design only plays from 96-24 or lesser sample rate. I love Auro 3D and play everything stereo in Auro 3D! So I have set the DSP menu in ROON downsampling not to 192-24/176-24, but to 96-24/88-24. Frankly, the difference sonically for 192-24/176-24 vs 96-24/88-24 in "native" stereo is so minimal I can not or barely hear any difference, but the difference using Auro-3D in terms of increased dynamics and even better soundstate is awe inspiring for me! If you input 192-24/176-24 stereo, and engage Auro-3D, the Altitude will ignore Auro-3D and play native 2 channel also using your subwoofer(s).
I have tried other sonic audio modes to expand two channel and I find them lacking, I'd rather use "native" stereo. But Auro-3D is another story totally, its amazing!
As for an external DAC for front left and right, why bother? I thought about this and decided against even the trouble. The Altitude 32 is so darn transparent - there's a lot more going on in the software than just the DACs. There have to be software reasons, and software integration, as to why the Trinnov Altitude 32's pro DACs sound so darn fantastic, at least for me in comparison to my prior Theta Casablanca IVA SSP's Extreme D3 DACs, the latter which are touted as easily the best sounding in the AV industry for SSPs. Yet the Altitude 32 sounds better to me in every way! If you have an external DAC, I recommend first using the Altitude 32 for several months as is, then trying the external DAC, I suspect the external DAC may well not sound any better. I debated getting a "better" external stereo DAC to try out and I decided against it, why bother?