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Sorry, it is what you say that is wrong. Because the end result is standard PCM, the quantization can be only worse, not better. Oversampling ADCs push a much greater quantization noise into the inaudible range, and then, by low-pass filtering, reduce the quantization noise to the level of standard PCM. Oversampling ADCs are not better, they are much cheaper, because 16-bit or 24-bit quantizers with enough speed and accuracy are extremely expensive. Oversampling, i.e. sigma-delta modulation, in both ADCs and DACs, allows the use of much cheaper quantizers with low resolution, of only a few bits, or even of only 1 bit, and of much cheaper filters, which do not have to be very steep, without degrading too much the quality in comparison with real PCM conversion done at the Nyquist frequency. |