Can anyone tell me what a 20 bit D/A does when presented with 16 bit data?
With oversampling a 16 bit D/A can output discrete levels corresponding to a 20 Bit D/A. That must be what is going on.
In any D/A the least significant bit, and sometimes two, usually toggles randomly from a one to a zero. If you use a 20 or 24 bit D/A to process 16 bit data, at least you can be sure that bit 16 is out of the noise level. For example, you could zero out bits 17-24, and essentially have a noise free 16 bit converter.
Oversampling came into the audio field with the first Phillips CD players. They used a superior quality 14 bit D/A with 4X oversampling whereas Sony used a true 16 bit converter that was less than perfect. The Phillips players sounded much better than the Sonys, but the part that really makes me chuckle is that Phillips, who was in partnership with Sony on the CD development, never bothered to tell Sony what they were doing until it was too late for Sony to react.
With oversampling a 16 bit D/A can output discrete levels corresponding to a 20 Bit D/A. That must be what is going on.
In any D/A the least significant bit, and sometimes two, usually toggles randomly from a one to a zero. If you use a 20 or 24 bit D/A to process 16 bit data, at least you can be sure that bit 16 is out of the noise level. For example, you could zero out bits 17-24, and essentially have a noise free 16 bit converter.
Oversampling came into the audio field with the first Phillips CD players. They used a superior quality 14 bit D/A with 4X oversampling whereas Sony used a true 16 bit converter that was less than perfect. The Phillips players sounded much better than the Sonys, but the part that really makes me chuckle is that Phillips, who was in partnership with Sony on the CD development, never bothered to tell Sony what they were doing until it was too late for Sony to react.