ProtoDAC TDA1387 X8 project

[hifinet]

ProtoDAC is NOS (nonoversampling) and it also does not have an output filter. The frequency response graph would look similar to the Pono Player. However, I think you would only experience the high frequency roll off (called the sync droop) if you can hear over 22.05kHz (for 44.1kHz recordings).  Using a sharp reconstruction filter with a corner frequency of 22.05kHz there would be no sync droop. This seems very counterintuitive.  Just like the other DACs with oversampling. Wouldn't normal human hearing provide for an adequate reconstruction filter? If the sample rate was 48kHz, you would need hearing > 24kHz to appreciate the sync droop. Subjectively, I have not been able to hear the sync droop. ProtoDAC does not seem to have rolled off high frequencies, but I am old and my hearing is no where near normal.

My own experience with power supplies. The Allo 5V 3A SMPS is clearly noisier subjectively than the 5V ultracapacitor supply in the PurePi.