I'm looking at PCM1794 as the last performance DAC chips (if there's something better for 24/96 audio, please let me know; I decided against the PCM1704 due to not only price but also low dynamic range).
However, the oversampling seems to be fixed at 8x. According to posts by the respected DAC designer Dan Lavry in another forum, lower amounts of oversampling are better (with of course steeper analog filters) since there's less jitter problems at the lower frequency. So, is there anyway I can get those DAC chips to run with lower OS?
According to the PCM1796 datasheet, there are two places with oversampling in the DAC, one being the digital filter (fixed), then the advanced segment modulator, which is changeable by software: "The OS bits are used to change the oversampling rate of delta-sigma modulation." Now, in terms of jitter performance, is the overall rate important, and thus changing this latter setting achieve what I intended from the beginning? Also, it seems the PCM1794, which has better overall performance ratings, doesn't have this ability.
The PCM1794 datasheet has a section called "Application for Interfacing With an External Digital Filter". I'm not quite certain if that means it will bypass the internal filter and will thus allow 4x OS to be used. Also, are there any performance penalties from using an external filter?
However, the oversampling seems to be fixed at 8x. According to posts by the respected DAC designer Dan Lavry in another forum, lower amounts of oversampling are better (with of course steeper analog filters) since there's less jitter problems at the lower frequency. So, is there anyway I can get those DAC chips to run with lower OS?
According to the PCM1796 datasheet, there are two places with oversampling in the DAC, one being the digital filter (fixed), then the advanced segment modulator, which is changeable by software: "The OS bits are used to change the oversampling rate of delta-sigma modulation." Now, in terms of jitter performance, is the overall rate important, and thus changing this latter setting achieve what I intended from the beginning? Also, it seems the PCM1794, which has better overall performance ratings, doesn't have this ability.
The PCM1794 datasheet has a section called "Application for Interfacing With an External Digital Filter". I'm not quite certain if that means it will bypass the internal filter and will thus allow 4x OS to be used. Also, are there any performance penalties from using an external filter?
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