I'm trying to run an optical signal from my PC (source) to 2 units: A
Cambridge Audio receiver (for driving my speakers) and an old Sony DAC/
processor (for my Stax headphone rig).

What I've done is taken an optical cable from my PC, put an optical
(1:2) splitter on the end, then run one cable from the splitter to my
Cambridge receiver, the other to my Sony DAC.

The Sony receives the signal perfectly, yet the Cambridge won't lock
to it. I've tried almost every possible combination of cables and
splitters, and experimented with other digital sources but no joy -
it's clearly the Cambridge can't cope with a splitter in the chain.
This is even when I just run one cable out of the splitter. Curiously
though, even with the splitter in, when I run a digital out of my Sony
DAC to the Cambridge, it locks on.

I've no knowledge of how optical signals work but can only conclude
that somehow the splitter halves the strength of the signal ans the
Cambridge isn't sensitive enough to lock onto it. And that when I put
the Sony DAC in the chaain, it must somehow boost it.

To be honest it's a right royal pain. Can anyone explain or speculate
as to why the Cambridge won't work, and offer a possible solution?