Maybe, maybe not - does the Yamaha have a pad switched in the line? Do you get the same relative levels if you use a dynamic? Is the input of the Yamaha low impedance and the presonus high impedance (I'm assuming the mic is high impedance)?

The little I've had to do with phantom power suggests that it either works or it doesn't, the condensor doesn't actually need much voltage to do it's thing though if there is a preamp in the mic. it might need a bit more.

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