Which company manufactures this Ethernet switch for the other?

Let's see, these Ethernet switches support 100/1000 Base-T gigabit, which means the signal travels point-to-point over twisted pairs at speeds of either 100 million bits per second, or 1000 million bits per second.  This is much faster than Redbook Compact Disk needs which is about 1.4 million bits per second.

Please note carefully that Ethernet is not slowed down to match the audio rate! Instead the audio stream is chopped into packets up to 12,000 bits long (Gigabit can have non-standard longer packets if both ends agree!).  This means there is much more silence on an Ethernet Link than signal, punctuated by very short bursts of signal.

Each packet starts with a preamble, then the address of the sender and intended receiver (these are the Media Access Code or MAC addresses and are globally unique).  Finally, there is a cyclic redundancy check which allows corrupted packets to be detected.

The preamble is 56 bits alternating between 0 and 1 which allows the receiver to match the clock rate of the sender. 

When the receiver has to turn the packets into an audio signal, it has to assemble the incoming packets into a memory buffer, and then clock them out at a much slower rate which has nothing to do with the clock rate of the Ethernet!

Ethernet is essentially a broadcast technology, so all a connection box needs to do is listen to any transmission and broadcast it on all other connections.  This is what an Ethernet Repeater does.  An Ethernet Switch is slightly smarter - it looks at the MAC addresses in each packet and works out which physical cable connects to each address.  Then it only has to forward a packet down one cable (OK there is an exception for a broadcast message where the receiving address stands for all addresses).

My conclusion: jitter in an Ethernet switch is inconsequential because the audio stream has to be re-clocked from a memory buffer anyway. Errors in the digital payload are always detectable.  If you can hear a difference between switches, be suspicious of the EMI they are generating which affects your other components.

@drmuso 

The video absolutely refutes that jitter is a problem with Ethernet.  I tried to show why this is true!

Further, why anyone would want to convert Ethernet to USB is beyond me, unless it is the only thing the poor audio device can connect to.  There are many versions of USB to confuse matters more.  At least Ethernet is designed to be a local area network spanning entire buildings!  

There is really no merit using fibre-optics instead of twisted pairs for either external electrical noise-rejection or to reduce EMI from the cable.  We are talking GHz frequencies!

But an Ethernet switch is a switched logic device and just may inject nasty electrical noise into your other components via the power supply.

@audphile1 

All devices which are fed Ethernet must process the data packets and cache them into a buffer before reconstructing the data stream. The buffer acts like a solid state disk without the added complexity of file systems and disk blocks!

You mention using a completely different power circuit. For most dwellings, ’completely different’ circuits are joined together at the main distribution board which is often just a few feet closer to the power station grid. They are not really separate at all. My house is fed three phases, but all the single-phase circuits are joined to the same phase.

Strictly, wireless networks are not Ethernet at all. They obviously are more susceptible to interference from the plethora of other wireless transmissions and RFI.

Hardwired Ethernet is less susceptible but not immune. The topography particularly when crossing mains is important. Ethernet can be made 100% reliable by detecting and retransmitting faulty or lost packets, but this is not what streaming does!

Your Purist Audio Cat7 cable is built as shielded twisted pairs and many other cables are unshielded twisted pairs. The effect might be fewer corrupted packets but why this might translate into ’smooth and clean, just as the artist intended" is beyond me!

Not sure what this has to do with Ethernet switches, either ...

@cleeds 

Oh dear, you are way off reality here and the key to it all is the word 'streaming'.

The Internet can indeed be used to deliver bit-perfect transmission using the TCP/IP (Transmission Control Protocol / Internet Protocol) stack. This guarantees all packets are received and error-free even over unreliable transmission components like Ethernet.  Think file transfer and downloads.

However, streaming cannot afford the time to request retransmission of faulty packets.  It does not use TCP and instead uses the UDP/IP (User Datagram Protocol / Internet Protocol) stack which prioritises delivery timing over accuracy.

There is no guarantee that the stream of packets that arrives at your Internet gateway from Qobus or Tidal is perfect, or even complete.  (You might call your gateway a modem, or router, or switch, or somesuch but it actually mediates between your Wide-Area Network and your Local Area Network).

Finally, your gateway pushes the data packets over WiFi or better, Ethernet.  Ethernet on its own guarantees neither delivery nor timing.  You need higher level protocols like TCP to detect errors, missing packets and retransmission.  UDP does not bother with these niceties.

@audphile1 

What happens if the catching midget drops a catch?  Or the throwing midget has not received the next one to throw?

So where do your dedicated circuits join?  What devices, if any, isolate them from each other?  This is a serious question ... my dealer wants to loan me a power isolator which sits on a single circuit