Fully differential amplifier - adder?

Question

I have two signal sources providing the same differential audio signal (VIN1 and VIN2). I want to sum those signals. The result (VOUT) shall also be differential.

The idea is to take a fully-differential op-amp and to sum the inputs just as you would do it in a single ended inverting adder configuration.

Will this work?

A quick LTspice simulation seems to work as expected. However, I could not find any examples on the internet, so maybe I am missing something?

Answer 1

That works - both device inputs are virtual earths so the currents from the signal sources sum at these points and you make a fully differential adder.