Have also heard this happen on a EMB-120, Same situation on take off power.
It ended up being the torque signal conditioner failing which resulted in a zero torque output and auto-feather activating. Very hard to figure out what the actual torque was during the auto feather as the would have been no torque reading.
I also think there was advise coming out from Embraer to ensure that the pilots switched off the auto feather as soon as possible.