| If I was you, use the 'groany' one, it is much less noticeable on the water.
What you are seeing, sorry, hearing, is the quest for efficiency and 'improvements' in technology.
In the 'old' days all the manufacturers used the ZN409 chip for their speed controllers, a dedicated servo chip, but they were limited as to how they pulsed the electrical signal to the motor. But they did give a nice quiet motor.
All manufacturers gave up on this many years ago and went over to new technology to give better control to the motor, the only problem is the one you have now, they are so efficient, they give great speed control but you just got to accept the noise. Some motors are less prone to it than others, but high performance ones suffer the most.
Electronize do one where you can switch between high and low frequency control, so you can have both noises if you want to, but not at the same time.
A sign of technology, one step forwards, two steps back.
A nice loud sound board can cover up most of it.
John |