A couple of points more here. When a 16 bit word is read from a cd, some form of processing, typically rate conversion, is needed to produce a 24 bit word from the 16 bit word. The rate conversion can be done inside the D/A chip, or it can be done in a processor preceding the D/A. The 24 bit word does not increase the information in the original signal, but just represents with higher precision the mathematical product of the 16 bit data word with the rate conversion filter coefficients. So Cjcerny is correct in assuming some form of processing to get from 16 bits to 24 bits.
Secondly, upsampling (typically done in a processor) can be significantly better than oversampling, 8x or otherwise, done inside the D/A chip because the quality of the upsampling filter can be much better than that used in most D/A chips - so there can be a significant difference in upsampling vs oversampling depending on where and how the rate conversion is done.
Thirdly, Cjcerny is correct in using the term 'bandwidth'. Bandwidth is frequently used in digital processing to mean total bits per unit time (e.g. the increased bandwidth of DVD), and not just to mean spectral bandwidth.
Secondly, upsampling (typically done in a processor) can be significantly better than oversampling, 8x or otherwise, done inside the D/A chip because the quality of the upsampling filter can be much better than that used in most D/A chips - so there can be a significant difference in upsampling vs oversampling depending on where and how the rate conversion is done.
Thirdly, Cjcerny is correct in using the term 'bandwidth'. Bandwidth is frequently used in digital processing to mean total bits per unit time (e.g. the increased bandwidth of DVD), and not just to mean spectral bandwidth.