I'm trying to learn how to select the correct output transformers to match the load impedance of my 23 ohm headphones.

So the output transformers are matching "line matchers".

The turns ratio is 5.1 with 15K ohms/600 ohms.

I'll use a matched pair (left/right) in my tube amp build.

Please correct me but my understanding is that

5.1 squared = 26.01

so then i multiply

26.01 x 23 ohms = 598.23 ohms

so then 598.23 is close enough to 600 ohms which means the above output transformers are perfectly matched to the 23 ohm load of my headphones.

Right?