Streaming clarification

[David A]

This is exactly my impression, not only for PCM to DSD conversion, but for any DSP I tried in Roon. Something of the naturalness and purity of the sound is lost...

I have the same impression when I activate the Devialet's DSP (for example, SAM).

Interesting. I have a bit of a love/hate relationship with SAM. When I got my 130 Pro nearly 6 years ago, before the CI board and the FW update that turned it into a 140 Pro, I was using a pair of Dynaudio Contour 1.3 SEs and I quite liked SAM. When I upgraded my speakers to Focal Sopra  2s I had difficulties with SAM. I've got an awkward room, it's L-shaped with 2 large open archways into it and no place where I can place the speakers in a symmetrical relationship to side walls because of the shape and openings. As I played with speaker placement for the Sopras and also with the placement of my physical acoustic treatments which are free standing I discovered that the effect of SAM was strongly dependent on what the room was doing to the sound in the bass region. Some speaker/acoustic treatment configurations made the use of SAM both highly noticeable and highly objectionable to me while SAM had a positive result with no drawbacks I could notice in other configurations provided I kept the SAM level very low. It took a long time but I eventually found a setup where the speaker and acoustic treatment placement worked really well without SAM and using SAM at 0%, just for the phase correction benefit, gave a subtle positive benefit without any drawbacks I could hear. That's the way things are running now.

I do think SAM is a useful feature with positive benefits but that its benefits are highly sensitive to room and speaker setup. Devialet's limited info on SAM suggests that you can just dial in the level setting for best results but I found that simply is not the case. SAM is said to work below 150 Hz and room effects dominate what we hear in those regions, exaggerating some frequencies and reducing other frequencies. SAM applies phase correction and the speaker's phase response varies immensely within the SAM range. Put the 2 together and the results are unpredictable. As I experimented over time I found setups I liked where SAM had a positive effect and other setups I liked where it had a negative effect. In setups which I didn't like, SAM didn't "fix" the things I didn't like.

SAM is definitely not a tool that always delivers good bass and it doesn't always make good bass better.  If you've tuned your room setup to get a result you really like then SAM may be just the right finishing touch or it may be the wrong finishing touch but if your room setup isn't giving you the result you want then SAM is not going to fix that. In my view SAM is worth trying if you like the result you're getting without it but you may find it doesn't work for you, at least with your setup at that time. If you're not getting a result you like without SAM then you definitely need to start playing with your setup in order to get a result you like because SAM on it's own won't fix your problems.