我根据 1794 年的手册制作了一个 PCB。IV和LPF都使用手册中的原始电路，并以单声道模式运行。左右通道采用8x TPS7A系列超低噪声LDO芯片，分别负责+3.3V、+5V、+15V和-15V。音频通道采用4层PCB，0.1%精密薄膜电阻和NPO滤波电容。通过合理的布局和去耦，得到了非常漂亮的信噪比和博士。这是我第一次接触音频测量。我使用的是e1da ADC，它具有与ap555相同的精度，因此测量结果更可靠。这次我做得好吗？也许它不能与ESS或AKM芯片相提并论，但在同一个PCM芯片中？
我注意到dddac在论坛中使用了nos1794。该方案的参数是否足够低
我注意到dddac在论坛中使用了nos1794。该方案的参数是否足够低
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I would suggest its possible your supplies for analogue reference are not up to the job, or there is an issue with your layout in that area.
My friend told me that the distortion at 44.1 sampling rate is really different from that at 192 sampling rate, which may be a normal phenomenon, so this is no longer a problem. I don't think the PCB I painted will cause so much distortion. Maybe it's due to IV and LPF.
This is the latest test result. There is still some gap with the 0.0004% thd + N in the manual. I'm wondering where to improve and where the source of thd is. Do you have any better suggestions?
