My main sources are Flac up to 384khz (most being 192 or 96) and some DSD files. I don't expect 768khz to be a lot better (or even feel a difference), but thats what Topping is selling and the drivers don't output that in my experience (tested both Asio and Wasapi).
At this level of sound sampling the sound quality issues I get concern the album itself, how it was recorded, mastered, etc. Some albums sound incredibly good, and others sound as good as an MP3 version of it (too much compression when mastered, etc).
On the sound quality overall topic, only a few of the best recordings I have sound really better (usually recent recordings of acoustic music such as classic music or jazz).
I dont understand why Jose Hidalgo got so nervous about my question. I am simply checking that the devices I have are correctly setup.
The only thing that doesn't make me happy with the Topping experience is that the L30 headphones amp gets hot like crazy and it's output is barely enough for some headphones (such as the Beyerdynamic DT 990 PRO) when listening to albums with high dynamic range and high quality (>96khz, DSD, etc), making the sound too low. I also think that it lacks a bit of bass punch (compared to the Musical Fidelity V-CAN II), but the sound is overall very natural.
Back to the DAC, as I said, I think it sounds better than the Audio Fidelity V-DAC II I had). But the difference is barely noticeable. The main reason I am changing DAC is because I am changing computer and I will no longer have a coaxial out (and old DACs are less good over USB usually)
I tried several DSD files on Foobar2000 after following the setup recommended by Topping and in my opinion the same files sound the same or even better when I read them on Aimp (outputs 384 PCM via Wasapi), because the DSD sound sounds a bit too crisp, sometimes with subtle cracks and less bass (some of these DSD files where recorded from LPs which seem to explain this). But really, I would say that I feel no difference between DSD and PCM on those tests.
I am not an audiophile fanatic. I want my music to sound good, as close as possible as being on stage with the musicians. And I want the devices I buy to work properly. That's all
I don't expect to increase sound quality by magic like in the Hollywood movies when they can zoom into a garbage picture and find incredible details thanks to some magic algorithm. I want realism... even when that means confirming that an album you love was really poorly recorded / mastered (both ?)
Aimp remains my main player because it is a lot easier, useful and sexier than Foobar2000. In my opinion it is just the best option (at least on PC), and I wasn't able to find any quality difference that would justify changing to F2000.