Guermantes
Senior Member
The Topping D30 uses a CS4398 chip for DAC purposes. Its datasheet can be found here and shows two selectable filter settings: fast and slow rolloff. The appendix at the end shows frequency response measurements for each filter type. Page 11 indicates the fast filter has a stopband attenuation of 102 dB in single speed mode (48 kHz sample rate), 80 dB at 96 kHz and 90 dB at 192 kHz. Page 12 lists the equivalent specs for the slow rolloff filter as 64 dB, 70 dB and 75 dB respectively. Cirrus do not indicate whether either filter is linear or minimum phase, though I suspect the fast rolloff filter is linear phase. Perhaps someone else might like to shed light on this. The DSD module has it's own filter fixed at 50 kHz.
I have a device (Fiio X3 II) with this DAC chip that allows selection of the filter type. It seems the Topping does not have that option. The Fiio doesn't produce the aural artefacts you are describing with either filter setting.
I can't see anything in the datasheet that might allow Topping to spoof the measurements as alleged. Amir has done a teardown of the D30 with no sign of extra DSP: https://www.audiosciencereview.com/...ds/hardware-teardown-of-topping-d30-dac.2230/
I've done my own ad hoc tests on my D30 and compared it to a Topping D10, Apogee Rosetta 200, HifiBerry DAC+ Pro, HifimeDIY Sabre USB DAC, RME Fireface UFX and whatever DAC is inside the Genelec 8260A monitors (listening only). I used track 15 from this classical piano album as one of my 24 bit 96 kHz test tracks: https://www.deutschegrammophon.com/au/cat/4798308.
All of the DACs had their pros and cons. The D30 had more electrical hum than the pro gear but slightly less than the D10 and HifiBerry. None of the DACs exhibited anything like the artefacts on the piano recording you are describing, even when switching between linear and minimum phase filters on the HifiBerry (in fact, the HifiBerry measured relatively worse than the others for aliasing artefacts because of poor stopband attenuation). I felt the D30 was good enough that I pressed it into service as my main DAC in my music streaming rig at home. I listen to a lot of complex orchestral, choral and solo instrumental music (like this) and don't have any issues.
Perhaps your Topping D30 is performing below spec and producing more harmonic distortion than it should?
I have a device (Fiio X3 II) with this DAC chip that allows selection of the filter type. It seems the Topping does not have that option. The Fiio doesn't produce the aural artefacts you are describing with either filter setting.
I can't see anything in the datasheet that might allow Topping to spoof the measurements as alleged. Amir has done a teardown of the D30 with no sign of extra DSP: https://www.audiosciencereview.com/...ds/hardware-teardown-of-topping-d30-dac.2230/
I've done my own ad hoc tests on my D30 and compared it to a Topping D10, Apogee Rosetta 200, HifiBerry DAC+ Pro, HifimeDIY Sabre USB DAC, RME Fireface UFX and whatever DAC is inside the Genelec 8260A monitors (listening only). I used track 15 from this classical piano album as one of my 24 bit 96 kHz test tracks: https://www.deutschegrammophon.com/au/cat/4798308.
All of the DACs had their pros and cons. The D30 had more electrical hum than the pro gear but slightly less than the D10 and HifiBerry. None of the DACs exhibited anything like the artefacts on the piano recording you are describing, even when switching between linear and minimum phase filters on the HifiBerry (in fact, the HifiBerry measured relatively worse than the others for aliasing artefacts because of poor stopband attenuation). I felt the D30 was good enough that I pressed it into service as my main DAC in my music streaming rig at home. I listen to a lot of complex orchestral, choral and solo instrumental music (like this) and don't have any issues.
Perhaps your Topping D30 is performing below spec and producing more harmonic distortion than it should?