Having a hard time tuning into organising an optical waveform 'cleaner' for the Edifiers ... I know what needs to be done, but my loss of energy in recent times is making my interest in sorting the technical design not intense enough to follow through, right now - yes, I could just buy something, and tweak that to get the job done. But that's not the point ... the goal is a low cost solution, commensurate with the cost of the audio components on either side of the conditioner; and requires most effective use of easily available, excellent value for money parts. This is not trivial - and hence the delay ...
In the meantime, , experimenting with ways to get the DVD player to deliver a better waveform over optical, by how it's operated. Warmup, and changing the sequence of operations to start play makes a big difference; and have evolved a pattern that gives good results. First of all, reload the first CD multiple times; which stabilises that side of the mechanical areas. Then, jump through all the tracks on mute, to the end and back - this exercises that part of the player's assemblies ... and only then, hit play. And do this routine for every new disk that's put in.
Tiresome? You bet!! Sometimes this is still not enough; a track will show signs of sub-par SQ - and for some reason, to do with how the machine's electricals alter with its operation, hitting pause and then skipping up and down quite a few tracks, with a final skip to the track not up to par, and starting play again, 'refreshes' the machine ... and SQ is back to a good standard, again.
Again, why? Well, the implementation of a low cost player means many electrical areas are borderline "good enough" - and doing things to 'wake up' the circuits can be of benefit - equivalent to revving a car engine "to clear its throat", when it's running roughly .
Of course, adding that waveform cleaner will make the need for this fiddling go away. But this interim, workaround kludge means that I can get satisfying playback right now, without jumping through hoops I'm not motivated to tackle yet, .