S.MS.L D300 Native DSD DAC Review with Measurements

[pkane2001]

3 hours ago, Miska said:

Yes, for example Holo Spring (1) was doing that. Thus best way to verify is to play for example 1 kHz tone from 48/24 source and check with spectrum analyzer from the analog outputs that the output is actually 1 kHz...

 

I've run into this testing SMSL DO100 while using DSD. Everything looks great, except for the actual frequency of the test tone at the output not being 1kHz when using 48k-based rates. Instead it's at 1kHz * 44.1 / 48 = 0.918kHz:

 

 

 

EDIT: I lied about all else looking great. This is the difference between 44.1k and 48k with DO100 - check out the noise floor difference:

[pkane2001]

9 minutes ago, Miska said:

That noise slope lift from 40 kHz on doesn't belong to DSD256 data. It is the ADC? Or maybe it's the ESS chip in question, not sure.

 

Same ADC for both (RME ADI-2 Pro FS at 768k), so I doubt ADC is at fault. It knows nothing about DAC DSD rates. Seems to be something in the implementation of DO100 or the ESS chip, like you said. In any case, 48k rates appear very broken with this DAC.

 

PS: 64x, 128x, and 512x 48k rates appear to have expected (normal) noise floor. Only the 256x48k rate produces a raised one. 100% repeatable with my DO100.

 

[pkane2001]

2 minutes ago, Miska said:

So you get very clean output at DSD256. But then DSD512 seems to get decimated to lower rate and as result it triggers again those ESS modulator spurious tones and some noise aliasing at the top of the frequency band.

 

I'm not as concerned with noise floor above 100kHz as the noise floor being 20dB higher in the audible range :) 

 

DO100 has the same problem with DSD512 -- it appears to be reduced to DSD256 rate, instead, even though the display says 512.

 

 

 

[pkane2001]

27 minutes ago, Miska said:

 

You mean 44.1k-base vs 48k-base? For 44.1k-base the different rates should give same audio band noise floor (like they do for example on above DL200, and from earlier experience I know also for ES9038Q2M such as on Pro-Ject PreBox S2 Digital where also DSD512 works fine and which is synchronously clocked).

 

 

I was referring to the DO100 256x48k noise floor being 20dB higher than with 128x48k or 256x44.1k. I believe that rate is not recognized correctly by that convertor.