"That is a surprise to learn that Eventide is cutting corners on the power supplies of such an expensive pedal?!"
I don't think so… Look around and you will see that a 9V, 12V or even a 24V power supply will cost about the same, for the same wattage (power). Higher voltage definitively does NOT translate to more expensive electronic (Luckily for EU contry running on 220V instead of 110V) 
Also, I'm pretty sure that the electronics inside is running at 3.3V or 5.0V and for that reason there's certainly a voltage regulator inside the pedal itself, reducing the voltage even lower than 9v. This is because ALL todays microprocessors, memories and other chips are running at either 5.9v or 3.3v…
There's maybe some "obscure" reason why one could see a difference between using a 9v or 12v power supply, but I believe this is mostly suggestive difference.
LA
