Topping NX4 DSD v DX3 Pro or DX7S

[Iain]

I recently purchased a Topping NX4 DSD DAC that was DOA.  I exchanged it for a new one and now the replacement seems to be misbehaving, as well. That said, do Topping have a QA problem?

 

The NX4 DSD appears to be unable to switch modes from DSD to PCM and will erroneously decimate DSD to PCM. The rear light is constantly blue, never red which will indicate DSD processing. Is this normal?

 

So it now appears time to make a decision. Do I try for yet another NX4 or look higher up the food chain at the DX3 Pro or the DX7S? Will these be better behaved?