Hi Pippin, to your underlying question: why do the filtering externally rather than in the DAC chip? The answer is "I don't know". When I bypass the internal filter and do it externally using a basic simple filter it sounds much better. And it's not just me. I've done this in blind fashion with a number of people and they all came to the same conclusion, the external filter sounded much better.
Looking at the spec sheets for the DAC chips you can tell that they are using cascaded filters. When I use an external FPGA to implement a filter and program it to be cascaded multiple filters, I hear a similar sound, when I implement a simple filter (no cascading) I get the better sound. The conclusion seems to be that it is somehow the cascading of filters that causes the problem. Again no clue at all why this is so, what the mechanism is etc. They ARE different filter functions, they do output different bits, but they are very close to each other. Whatever it is, its not a big difference in the waveform. John S. ------------------------------------------------------------------------ JohnSwenson's Profile: http://forums.slimdevices.com/member.php?userid=5974 View this thread: http://forums.slimdevices.com/showthread.php?t=99088 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
