Is less than 24 bits worth it?


I see so many attractive CDP's for sale on this site that have 18 and 20 bit resolution (Naim, Theta, Classe, etc.) Does it make sense to still buy one as a stand alone or should I only consider 24 bit? Thanks for the advice.
easy_e
I've heard it said that the state of the art advances by a little more than one bit per decade. Certainly right now more than 20 bits are lost in the noise floor.

As the others have said, a well-executed 16-bit player sounds better than a typical mass-produced 20-bit player, and usually by a wide margin.

It's just like with power amps: not all 100 wpc amps are equal, and there are lot of 50 wpc amps that sound far better than many 100 wpc amps with most speakers.
When the analog signal is finally created, both amplitude and phase inaccuracy create deleterious effects. Using 24 bit resolution, the last bit translates to a signal amplitude of about a 17 millionth of peak amplitude. You can get an "equivalent" effect if the exact timing of that 24 bit sample is off by mere nanoseconds (depending on the exact slope at the sample moment), which is nothing more than jitter. Jitter that can affect the difference in timing from one sample to the next is created by intrinsic oscillator noise in Phase Locked Loops (the thing that tracks and creates the internal clock) or by the very bit stream itself (a phenomenon called data dependent jitter). CDPs can be more successful than transport/DAC combos in addressing these effects. Both have a really tough job getting true 24 bit resolution.