I think we need to clarify the USB Audio issue. When I said we are trying to improve the USB Audio performance through firmware and Driver update, I was referred to the noise and stability issue when N5ii or N5iiS works as USB DAC. On the other hand, the delay is NOT a bug. The USB DAC of N5ii and N5iiS has been advertised and documented as operated in Asynchronous transmission mode. This is a natural design choice when we design an audio product for high fidelity playback and we have explained the issue upfronted, please check out explanation HERE. If you want to cross check with other audio manufacturers, the following video from Cambridge Audio explained the various options (synchronous, adaptive and asynchronous) briefly. Additional reference are available HERE, HERE and HERE. I hope you can accept the industrial consent that Asynchronized USB transmission is the appropriate choice for a Digital Audio Player.