I have a need to split the outputs of a mixing desk to drive two separate
devices. Because a distribution amp provides more features than needed
(more than 2 outputs in most cases) and costs a lot more, I also looked
at using a mic splitter transformer e.g.
http://www.jensen-transformers.com/datashts/dinms2p.pdf

The main issue from what I can see is the maximum input level the
transformer can accept, around 2dbV typical. Specs on the mixing desk say
its maximum output is +21dBm, although the output impedance is 75 ohms.
The input impedance of the transformer is around 1000 ohms, so the
voltage across the primary would be quite a bit less than the desk
output.

As the desk is designed to drive a 600 ohm balanced line, I'm assuming
that driving a transformer would provide a similar load to it.

Obviously we can just connect our devices in parallel without a
transformer; the point of using the transformer was to match the
impedances on the various pieces of equipment.