I would be curious to see the diagram, not doubting you but sometimes the details get lost in those not really well and clear manuals. For example, in the SMs that I do have, the 1020, 1025, 1018 mentioned, the DAC WM8728 is for the digital path, whereas for the analog, for some strange reason they use the AK4588 (for the 1020/1025), and in the case of the 1020/1025, the AK4114. Again, to me, and likely to many others, this is mostly academic, DACs at those level, while not great on specs, usually are not the bottleneck for most people with normal or less than normal hearing. But people hear, or think what they hear, so I stopped debating on claimed audibility a while back.