Ted Smith said One of the obvious things missing from a flat FR is the phase response. If the group delay is constant (i.e. the phase of each frequency is such that the filter just looks like a simple time delay) then a flat FR should get close to neutral. If phase response is something else then non-steady state tones will get muffled, e.g. transients will loose their edge/timing.But Frequency response and phase response are measured with steady state tones.
The next detail is the simple distortions -
there’s time distortion, say small echos or acoustic feedback from the speakers affecting a turntable or the filaments of a tube or (thru a board vibrating) the capacitors in the electronics. Often this is perceived as adding richness if the feedback is in the right frequency ranges. Too much feedback at higher frequencies can detract from clarity and/or affect the sound stage.
there’s frequency distortion: e.g. harmonic distortion can add richness (“tube distortion”) or cause things to be a little harsh (old “transistor radio distortion”), intermodulation distortion is a little more complicated.
Then come less linear distortions - noise, jitter, etc.
If the noise is correlated with the sound then in the best case it can add a little richness at the expense of localization or change the tonal character of the sound, etc. - if it’s not correlated with the sound, but isn’t white it can be confusing to the brain. White noise can be fairly benign.
Jitter spreads each frequency in the audio outwards just a little - the audible effect is hard to characterize. I hear high frequency jitter as a little fuzz on the sound, and some loss of localization of the sound stage. To my mind it’s a big part of what people describe as the “digital sound”. I hear lower frequency jitter as messing with the foundation of the sound - sort of taking some of the realness/life out of the music.
I’m just rambling, but adding distortions digitally really doesn’t give the same audible effect as simply adding a (not quite perfect) tube buffer or putting some base traps in the right places in the room…
Thanks Ted!
Many aspects in its sound speak for the DS doing things more right than others, which could mean, previously existent more richness could have been due to existing Jitter/noise/phase issues/THD/resonances etc.
Aside of discussions around taste and preferences I personally have no problem accepting, that add. richness and harmonic structures, some might prefer, probably come from above mentioned possibilities of errors and have other drawbacks, no matter if in vinyl or other digital gear playback with richer sound.
Die hard vinylophobes might need also a theroretically positive aknowledgement of their preference, I don’t. Manufacturers of other, different sounding digital equipment with flat FR and lot of work invested in reducing noise/Jitter etc. might not agree, but that’s not my problem. I hear what the DS does better and what I have to accept as a drawback in my preference is managable.
I see the following facts and conclusions:
- All digital gear is mostly claimed by all manufacturers and reviewers to have flat FR but as we know can sound very different in tonality and intensity of tonal colors reproduced
- Out of your explanation I conclude (you didn’t say that and I understand it) that the additional richness other digital sources with flat FR reproduce in side2side comparison to the DS, could practically just come from less care taken in decreasing Jitter/noise/phase issues/THD etc. Thereby I take it that comparing digital sources in the same environment on heavy platforms doesn’t lead to any differently introduced vibration that could manipulate sound.
- A system can easily be setup, so that the DS makes fantastic and rich enough sound. In such systems, other clearly richer sounding gear (of which not just a few exist on all quality levels) must sound somehow „too heavy“. At least this is my experience and quite logic.
- Out of these conclusions and counting you as the master mind in the digital area, I currently see improvements in the digital domain going in a different direction, means that one has to search for add. richness (if he needs) somewhere else than in the digital source.
This makes it theoretically hard for colleagues like yacheah where to address the problem solving, as all parts should theoretically sound the same in tonality. Practically it’s different as we know and we all choose components or at least one component also by it’s tonal character, may it be source or amp or speaker.