Do I really need an " Audio Grade Network Switch "?

The timing information for a digital music stream is encoded into the data. The exact timing and rate at which packets are transferred makes no difference unless so many packets are dropped that the playing device's input buffer is drained. The only hardware clock that might affect the music is the one that the DAC uses.

I think we are all making the same point and my English is not good enough and I got too technical.

All I wanted to say was that even the little timing information provided by RMII could not be used for anything else than to ensure the RX processes the the data symbols correctly.

Thus claiming that an "audiophile" switch can enhance how the encoder/decoder process data is non-sense because the only refclk reference the encoder/decoder has it is in its bus.

Need to get ready to work, good night to the USA.

@astolfor 

The interface between a PHY device and the CPU are *INTERNAL* to the design of the device.  Once the signals reach the PHY and are emitted to the Ethernet wire, there is no clocking involved.  You are looking at BOARD LEVEL HARDWARE design (RMII bus).

This has nothing to do with how the signals on the Ethernet wire travel.

Using Audiophile so called Network cables and switch and additional network gear to improve the sound made some difference with a poorer quality Network Streamer like SOTM and other Chinese made stuff.

Once i moved to a Quality Product, Like the Playback Back Design Dream Series DAC and Streamer which uses a proprietary fibre optic cable all the Network stuff i had made no difference whatsoever.

So it depends on the Streamer and DAC your using and how that can isolate noise and interference.

Personally i think So called Audiophile Network Cables, Switch and clocks are not needed at all and most of them are substandard off the shelf and rebranded as audiophile stuff.

It really comes down to how your Streamer can isolate noise and your DAC.

Yes, and preferably with a Linear Power Supply.