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

No you do not.

Also, for the un-informed, there is NO such thing as ethernet clocking. It is an ASYNCHRONOUS stream.

An el-cheapo switch like this will more than be enough:

It is also known as the "self learning bridge", plug & play, no configuration required. As long as you buy devices which are TRUE to the 802.3 and 802.11 standards, there will be no problems whatsoever. Cables will not matter diddly s..t either, AS LONG AS they are spec’ed to the standards.

Spend your money on a proper streamer and/or a DAC instead.

What is important however is NOT to place their SMPS wall warts next to sensitive analog electronics, like MC phono preamps.

@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.

Here is what this is all about, in a summary form:

- Cables and switches themselves do NOT in any way affect the system.

- However, the noise that they and/or their power supplies may produce, MAY
affect sensitive analog circuits if they are placed close enough and may lead
to the mistaken conclusion that the devices & cables themselves are affecting
the sound.

As long as you buy cables and switches which are compliant with the 802 standards, AND they are placed away from sensitive analog signals, you will have no audio issues whatsoever.

Galvanically isolated (optically coupled) devices will also improve  the noise floor.

Spend your money on better streamers or DACs instead.