[slinkelist] connecting two toslink digital outs from two changers together

[PaulMmn]

A digital signal is a lot different from the traditional analog 
signals we grew up with.

Analog signals are like streams of water:  You can join them together 
by just pouring them through the same pipe, much like running 2 
garden hoses through a 'Y' connector.  That's what analog 'Y' 
connectors do, electrically speaking.  Similarly, you can split them 
with the same 'Y' connector (although, like a stream of water, the 
split stream is 1/2 of the original (assuming a 50-50 split)).

A digital signal, however, is much different.  Information is sent as 
a stream of bits, assembled into blocks or packets.  Each 
block/packet can be compared to a business letter:  it has a date and 
time stamp; a 'send to' address; a 'sent from' address; a body (which 
contains the data to be sent); and a signature block (which includes 
error correcting information in some systems), which ends the message.

If you wrote your letters on clear plastic, then stacked them on top 
of each other, you'd be unable to read either of them, because pieces 
of characters from 1 letter would blend with characters from the 
other.  That's like trying to run 2 digital signals through a fiber 
"Y" connector.  Bad news.

In the real world, a digital audio signal is broken into thousands of 
packets, which are all necessary (if you don't have error correction) 
to move your audio from point A to point B.

Because these packets are constantly flowing, you can't just join two 
streams together.  You'll have packets from one source landing on top 
of packets from another source, causing loss of -both- signals 
(because you've mangled the signal).

A computer, or Nirvis' DXS, can read signals from multiple sources 
and switch them to different outputs.

Some systems can multiplex multiple digital data streams together on 
the same wire or fiber.  You 'simply' read the packets from 2 or more 
inputs, and write them to an output.  There are lots of things that 
have to happen-- you have to read from all the inputs fast enough 
that you don't miss any incoming packets, and write the data fast 
enough that all of it gets written.

It's enough to say that using a fiber "Y" will -not- let you blend 2 
digital signals together!

--Paul E Musselman
PaulMmn@ix.netcom.com