SMSL DO300 DAC Review

[IVX]

I'm an ordinary chinese worker. Aliens nowadays look like that https://en.wikipedia.org/wiki/Grigori_Perelman

 

[pkane]

I'm an ordinary chinese worker. Aliens nowadays look like that https://en.wikipedia.org/wiki/Grigori_Perelman

Then how did you come into possession of alien technology that beats an AP by 5-6dB?

 

[IVX]

the keyword isn't "alien" but "ideal analyzer", the analyzer with zero residual distortions and noise.

 

[jhenderson0107]

Here's Multitone Analyzer noise computation for APU+6dB notch into Cosmos ADC 192k (SMSL DO300ES 96k). Without bin subtraction, but with APU compensation curve applied.

Noise is -135 dBA as measured seems in line with your estimates:

View attachment 359356

pkane -

Eyeballing, the SFDR seems to be ~140 dB (H3), rather than the reported 149.4 dB. Please explain.

 

[pkane]

pkane -

Eyeballing, the SFDR seems to be ~140 dB (H3), rather than the reported 149.4 dB. Please explain.

On the chart, the result is indexed to 0dB, so what you're eyeballing (140dB) is relative to the amplitude of the signal. SFDR is reported in dBFS.

 

[jhenderson0107]

On the chart, the result is indexed to 0dB, so what you're eyeballing (140dB) is relative to the amplitude of the signal. SFDR is reported in dBFS.

I believe that spectral free dynamic range should be calculated in dBc, since it portrays the dynamic range between the carrier and largest spectral artifact. That's how I've always calculated it. But, perhaps I'm mistaken.

 

[pkane]

I believe that spectral free dynamic range should be calculated in dBr, since it portrays the dynamic range between the carrier and largest spectral artifact. That's how I've always calculated it. But, perhaps I'm mistaken.

Both are valid, but MTA computes it as dBFS.

 

[Blashyrkh]

Not by much. I'm measuring this with E1DA's APU notch + Cosmos ADC, so the result is different than Amir's as this setup has lower noise than APx555.

At -0.0dB THD+N is -127.3dB, and at +2.0dB it's -127.8, so 0.5dB better at +2dB setting.

View attachment 356565

View attachment 356566

So the default +2db is actually better and should be used?
Thanks for the test!