Ummmmm, good for a fixed install background music/sound system for say making "voice" announcements over ceiling speakers.
For a premium audio path? Not in a million years!
I don't recall the details, but we sourced these transformers from China for bottom dollar (yuan). There is probably magnetic shielding inside since these modules plug into mixer-amps with up to 150W power amps, and 70-100V audio output transformers for constant voltage sound systems. The mic input transformer needs to ignore the magnetic field from the nearby output or power transformer or nasty hum and/or feedback happens.
These utility products can sometimes be much harder to design than they appear. I recall one difficult project that only had a 5W amp inside, but with 100v output transformer and mic input transformers all in a smaller than a shoebox package (much smaller). It was not trivial to keep it from taking off and oscillating all by itself, especially when no mic was connected.
I recall when we first tried sourcing audio transformers from China, they didn't have a clue about what mu metal was (at least the guys I was using).
It was an interesting journey to source parts and make inexpensive industrial products that didn't suck, and they don't suck, but they were designed to an industrial background music level of performance, and mic inputs would be optimized for speech not full range music. In fact too much LF is a no-no in constant voltage distribution systems since the puny magnetics can get saturated if too heavy handed with the low bass, but that is another long and winding story.
JR
