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Take a look. It seems indeed high-level ultrasound blocks noise-shaping due to the risk of clipping at the tone frequency. The tone at 83 kHz has the greatest effect on Awt noise, although at this frequency the effect of the DAC LPF is already noticeable. The noise [20..20000 Hz] turns out to be...

I think it's too early to draw conclusions. I assumed that the white noise would block the shaping from working, but it looks like that's not the case. Even before your post I was unable to repeat the same experiment for the THD+N@1kHz test. Oh, sorry! I was incorrect, you didn't say exactly...

I'm pretty sure this combination is not good for producing high quality sound. I have never come across a high-sensitivity headphone among the best quality ones. Active use of the DAC as a preamplifier will surely degrade its performance. So, using the regular amp gain switches is still much...

You're right, it will have an effect. But we still won't get accurate data, because besides DRE there is also noise-shaping, which has different settings for different signal levels. Here is my post on diyaudio, where there is the measurement you suggested. The DRE can use a DAC modulator, its...

Look here: The CS43131 reproduces levels very linearly, so there is no audio noise reduction. In pauses, when playback is stopped DRE cannot work and the output signal is muted by other circuits or algorithms. DRE hides only its own DAC noise. All right. Let's check what the real dynamic range...

I believe that only technologies that are useful are interesting. There is no benefit from DRE, fake dynamic range will not improve sound quality. I agree that clicks are almost impossible to hear, and it is unrealistic to encounter conditions for clipping at 6-8 Hz, but the main question is...

Measurements are exactly what is needed to know the distortion added by the device. In this case, no one can say exactly what the THD+N will be. A difference of up to 6 dB is very large. I can't figure out how you have the stepped sine set to a negative step to generate signals down from 0 dBFS.

Uh, sure. This all makes the behavior of the device very unpredictable. By the way, can you describe how you perform measurements with decreasing signal strength?

Alas, that is what we are doing. I can't imagine any other possible cause for the 8Hz phenomenon. DRE will not have such consequences only if the chip has the ability to raise gain in advance, buffering a significant fragment of the digital signal. Clipping was observed only at signal levels...

The length of the FFT does not affect the result, except when it is too small. However, I have now noticed that this effect is not present on my cs43198 dongle. The smpte measurements above were made on CS43131 (meizu hifi), repeated tests of it show similar results with SMPTE dependence on Fs.

I see errors in your reasoning: 1. “JM20 Max H mode is turned off” - ok. I don't see any reason to doubt it, but it doesn't show a direct correlation. Here is the proof. I have two dongles with bare CS43131 and CS43198. Both exhibit clipping at frequencies below 8Hz and inaudible clicks. The...

Again I see unrealistically low SMPTEs. Intermodulation is one of the products of harmonic distortion. So it is very hard to imagine SMPTE -120 dB, while you get THD+N = -113 dB at 1 kHz, and at 7 kHz my CS43131 shows THD -108 dB. Can you please describe your measurement setup and show a...

Yes and yes. In any case you can point out logical mistakes to me. I don't understand what a multitone can show either. It is a periodic signal whose rms cannot cross the -11 dB level with a period of more than 5.5 sec. Varying the gain allows a high DR result, but the THD+N result on this...

Apparently you didn't read my post carefully. After the signal drops below -11 dB, it takes about 5.5 seconds before the amplifier power down is activated. Until then, no clipping can occur due to the H mode being activated. Therefore, there can be no more than 3 clipping events during the 10...

SMPTE levels far below -120 dB looks absolutely unreal. Check the manual fundamental override or something else maybe. Can you show the SMPTE FFT? You were able to measure distortion at high output levels. With my dl200 there was clipping in the APU. And THD start to grow a bit later. I've...

I'm not sure I understood you correctly. The external load on the chip was extremely low, about 200 kOhm.

@staticV3, @JIW, some time ago I measured such a series for a single cs43131 on a large bandwidth, but taking into account only 9 harmonics. The rise on the left is due to clipping, on the right to “pumping” harmonics by noise shaping. Curious what might change after averaging a few chips. I...

If you mean whether you can control the hardware volume from the USB host, no, that option has not appeared.

Only direct current or loud high-frequency content can harm your speakers. Neither of these things are generated by the CS43131 or others by themselves. The artifacts discussed may (or may not) be heard as features of the sound, but nothing more.

I tried Neutron HPF. To completely eliminate clipping at low frequencies with it, you need to have at least 36 dB of filter suppression at 8 Hz. For this purpose you need to set the cutoff frequency not lower than 70 Hz... well, it is not worth fighting with hard to notice defects with such a...