Picoscope 4262 audio DAC measurements - strange THD+N

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Joined: Sun Apr 30, 2023 2:45 pm

Picoscope 4262 audio DAC measurements - strange THD+N

Post by picolover2023 »

Hi all.
I'm looking to verify that I am using my new Picoscope 4262 properly.

I have a SMSL D-6 DAC which Audio Science Review has measured. I'm not expecting the Pico have anywhere near the resolution as the APx555 (obviously):

https://www.audiosciencereview.com/foru ... iew.36235/

But why is this THD+N and SNR so low in 'Spectrum' view but when I just switch to 'Scope view', the same measurement looks a bit more as expected ?

Spectrum view, THD+N and SNR at 54dBc (strangely low) - see attachment

Just switching to scope view, THD+N = 84dBc - see other attachment

As mentioned I don't expect to see SINAD of 113 dB like APx555 analyser found but there is huge difference between 54dBc and 84dBc

I'm obviously doing something wrong somewhere
Screenshot from 2023-04-30 22-39-11.png
Screenshot from 2023-04-30 22-40-08.png

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