Explanation of the report from Astell&Kern AK300

AK300 plays an audio stream of 44.1 kHz on the DAC is not direct. AK300 uses resampling. This is evidenced by the aliasing graph.

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AK300 have AK4490 DAC. AK4490 DAC have five presets digital filter. it's Sharp, Slow, Short Sharp, Short Slow and Super Slow. Aliasing graph from AK300 dues not similar to them presets.

AK300 have a similar graph as KANN

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if KANN connect to USB (as USB-DAC) digital filter works default preset Short Sharp. SRC off from Astell&Kern.

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SRC does not off in AK300 with connect to USB.

Quality of SRC is good. SRC have not visible distortions. Probably, sound stream 44.1 kHz upsample to 174 kHz. This algorithm replace path algorithm of digital filter from DAC.

Общая информация о характеристиках цифровых фильтров для ЦАП рассмотрена отдельно.

if external dac connect to spdif to AK300, soundstream out is correct without SRC.