Does Digital Try Too Hard?


Digital glare. A plague of digital sound playback systems. It seems the best comment a CD player or digital source can get is to sound “analog-like.” I’ve gone to great lengths to battle this in my CD-based 2-channel system but it’s never ending. My father, upon hearing my system for the first time (and at loud volumes), said this: “The treble isn’t offensive to my ears.” What a great compliment.

So what does digital do wrong? The tech specs tell us it’s far superior to vinyl or reel to reel. Does it try too hard? Where digital is trying to capture the micro details of complex passages, analog just “rounds it off” and says “good enough,” and it sounds good enough. Or does digital have some other issue in the chain - noise in the DAC chip, high frequency harmonics, or issues with the anti-aliasing filter? Does it have to do with the power supply?

There are studies that show people prefer the sound of vinyl, even if only by a small margin. That doesn’t quite add up when we consider digital’s dominant technical specifications. On paper, digital should win.

So what’s really going on here? Why doesn’t digital knock the socks off vinyl and why does there appear to be some issue with “digital glare” in digital systems.
mkgus

Showing 2 responses by cleeds

terry9

It follows that some form of interpolation is being used to convert the discrete sample values ... There seem to me to be only two alternatives: (1) stick with a safe linear interpolation, or (2) guess. But with a guess ...

No, there's no interpolation going on here - unless there's an issue reading the disc that requires error correction - and there's no guessing either. Neither is needed because it's a bandwidth limited system.


terry9
All you have to do is draw a sine wave. Then make 250 equally spaced marks on the x axis, starting with 0 and ending at 2pi. Use each mark as the step boundary of a step function. Just like elementary calculus.

Now calculate the mean square difference between that step function and the sine wave, and divide by the sine wave area - it’s about 5%. You may infer that 250 samples per waveform delivers about 5% distortion. Now, how many samples per 20KHz waveform?
This argument suggests that you misunderstand the math that underlies digital audio. You might want to view this.

Don't get me wrong - I'm an analog guy. But we can't improve digital if we don't understand how it works, and how it doesn't.