Best spec ADC Chip currently.... ??

[Ralf Stocker]

Too bad the 7th and 9th harmonics are so big.

 

[pkane]

Yes, the ADC is tweaked but not for best performance with oine source. I tweaked E1DA using Topping with ES9038PRO and SMSL with AK4499 - both sources show now optimal results. AK4499 shows -122dB and D90SE -123dB THD+N. Both DACs has slightly different harmonics, so this is not tweaked for one DAC only

Spending some time and tweaking E1DA Cosmos just for one DAC/source and one signal level you can practicaly get rid of 2nd and 3th harmnoic completly

Maybe, but the fact that APx555 showed higher levels of second and third harmonics (the ones you tweaked) makes it a bit more likely that what you've measured was a compensated performance of the whole chain, and not the DAC itself:

 

[mdsimon2]

In this case I have DAC in mono mode and ADC in mono mode - yes, it gives better performance than stereo, theoreticaly +3dB because of noise

It will increase the SNR of the ADC by 3 dB but should not necessarily decrease the measured noise level by 3 dB. Unfortunately in my experience when measuring DACs where a 3 dB increase in ADC SNR should have no change in measured noise level (because the DAC noise is so much higher than the ADC noise) if you use two outputs from the DAC and route them to the Cosmos in mono mode without a splitter you will see a 3 dB decrease in noise which is not correct. I described this in a bit more detail here -> https://www.audiosciencereview.com/...s/diyinhk-dac-measurements.23629/post-1068777.

Michael

 

[IVX]

So, if anyone wants to know the truth about your DAC performance deeper, need to use Cosmos APU notch, in that case, your test performance level gets a precision unreachable for AP555b. 6x times less noise, 2x times less THD+N.

 

[McFly]