What determines the THD+noise vs Freq in DAC?

[mslim]

Comparing apples and oranges here (different sizes ones as well).

Both the RME ADI-2 DAC FS and E30 use the same AK4493.

Questions:

1. Quite different THD+N vs Freq in the measurements:

What makes the E30 more jagged?

I have also noticed very few DAC can achieve a smooth line - I think Matrix Audio, RME, Benchmark to name a selcted few. So obviously some better engineering with added cost here. If I'm not mistaken, John Siau said Benchmark pays more attention to this.


2. Can you hear any difference in this?

 

[March Audio]

There are many, many factors that affect this.

The dac chip is only the first part of the chain, so dac chip specs are not a useful indicator of of what ultimately comes out.

So factors including but not limited to:

. Basic circuit design, there are different ways to skin a cat
. Performance of active components in the signal path, ie op amps
. Performance of passive components ie resistors and capacitors
. Specific values of passive components
. Circuit board layout and ground plane regime
. Power supply quality
. Noise from other circuit areas


And so on.

 

[mslim]

Thx. Which numbers should I pay attention to in the graphs to make sure this is inaudible?

 

[gvl]

Note that this particular test uses 90kHz bandwidth and often results gets affected by ultrasonic elements that are not audible but fall within the test band. And they are typically not harmonics but images or noise shaping products.

 

[RickSanchez]

Thx. Which numbers should I pay attention to in the graphs to make sure this is inaudible?

This tutorial may be helpful for you:

• https://www.audiosciencereview.com/...-thresholds-of-amp-and-dac-measurements.5734/