(03-Feb-2016, 06:25)deviousalet Wrote: TI PCM1798 (Phantom): 123dB SNR, 123dB dynamic range, & 0.001 THD+N
TI PCM1792 (Expert): 127dB SNR, 132/129dB mono/stereo dynamic range, & 0.0005 THD+N
Indeed. I meant to look that up originally and forgot. The PCM1792 is a much more expensive DAC chip but it is a constant current output chip. This means it will generate more heat as mentioned in the review. I am assuming that the PCM1798 by virtue of the fact that it is not a constant current design means that it's specifications cannot be as good. However, although TI give those very high figures, it is near impossible to achieve them in practical designs. So possibly what Devialet meant, is that after they optimised the usage of the PCM1798 though clever design, that it measured about the same in "real terms" than the PCM1792. Or they just got it wrong! Either way, you could never hear the difference between 123dB and 127dB SNR, or 127 and 129dB DNR. It also wasn't clear to me if there is just a single DAC chip in there, or multiple ones which of course affects the numbers too. Also remember the Expert is a stereo device whereas the Phantom is a mono one.
