My audio DAC does nothing with the signal, playing it back with the exact information that it was recorded with, bit for bit and at the native sampling frequency of 44.1 kHz. The DAC does have all sorts of oversampling, which is manipulation of the bitstream, yet it sounds best, by a long ways, in its non-oversampling mode.
Still I owned a PS Audio DAC for many years and it sounded great too, although I like what I’m using now a bit more. However, both are musical. When it comes to audio design and life in general, different strokes for different folks.
There is a fundamental difference between purifying water through boiling and distillation vs. merely filtering it. The first fundamentally alters the source while the second just modifies it.
Of course, this is the basis of our Power Plant AC regenerators, units that fundamentally alter the power coming into your home.
I am reminded of another kind of regeneration vs. filtering and this time in the digital domain.
In the mid-1990s, as digital audio was just gaining a foothold in high-end audio, we had learned a new term. Jitter. Jitter is a timing error, a deviation in time against a fixed standard. If that deviation happens at a quick enough rate we can hear its distortion. Slowly deviating jitter—measured in seconds, minutes, or years—is not audible.
No sooner had the subject of jitter bubbled up to the attention of the high-end audio community than clever engineers offered us a means to reduce it. Jitter filters were suddenly everywhere. These filters typically used a PLL (Phase Locked Loop) which is a fancy term for a way to detect variations in timing, speeding up or slowing down the digital signal to compensate. Better, to be sure, but still a Band-Aid in the way those early products worked.
That’s when our chief engineer, Bob Stadtherr, and I decided to take a different approach. Instead of speeding up and slowing down the data stream to get closer to an ideal periodicity, we decided instead to throw out the original data stream and generate a new one with a jitter-free clock. In other words, we regenerated a new digital signal free of jitter and changes in speed.
We called it the Digital Lens because it perfectly focused the digital audio stream.
Cleaning up a mess is effective, but rarely as good as starting fresh.