Hello,
It would appear that your EQ took the sacrificial hit and your H9 is going to be OK. The only thing that may concern me as an electronics tech is one aspect with semiconductors is they are able to take a bit of a over voltage or current hit and only degrade their functionality or lifespan. The source audio is probably not “true bypass” (using buffers) so the current from the speaker output did not jump over to the H9. Knowing Eventide the components are high quality and the input probably has some sacrificial diode which would fry quickly so the fact that your H9 is functioning properly and there’s no input audio degradation I would give it a 99% good diagnosis.
