I had posted this same question last year and got a few suggestions for adapters that are available for sale. I didn’t try any of the splitter/adapters as further investigation into other forums gave mixed opinions when it comes to the use of passive devices.
Sonifex (UK) makes an active device for SPDIF distribution but I chose to steer away from it as it has all RCA connections and I wasn’t impressed with the asking price (around $500 USD).
This weekend I ordered a AES/SPDIF distribution amplifier from Matrix Switch Corp. It is a single input four output device and all connections are 75 ohm BNC. The device normalizes all outputs to 1 Vpp. Although 1 Vpp is higher than the standard 0.5V input consumer electronics use I’m going to try it anyway. A friend who designs audio electronics believes it should work fine- we’ll test it once it arrives. If you’re interested in more information you can find it here.