You should get informed about moving a 16/24 Bit bus value to analog output. You can do this the classical way to push it onto an DAC which performs ->Interpolation, or do it manually by creating a PCM wave yourself from the data and filter it appropriately. The common way is to add a more or less steep -> anti aliasing filter with an edge frequency much lower than the sampe frequency and high as possible, which will cause a -> tradeoff for filter frequency. A good option is a 15kHz Filter with 25kHz stoppband and a sufficiant damping at 20kHz already using classical 44,1kHz sample frequency. The less steep the filter is, the less distorsion will occur, but also the more oversamlping will be necessary.
If You are only using one resistor-capacity combination (-> RC-Filter) high head room is required. You will also add non linear predistorsion too the PCM!
In my DAW, I am using up to 384kHz with parallel DAC non predistored and 200 MHz with serial DAC in predesroted manner, which practically is a "one bit DA-conversion". The Filter has an edge frequency of e.g. 75kHz with a non linearity of 20ppm only in the audible range below 18kHz, which is the best quality one can achieve at all.
http://www.96khz.org/htm/cyclone4platform.htm
