Reduce the fan noise at the 633 with a capacitor?


New member
If I put my fans to my 633 there is a noise.
It is caused by the PWM signal (like also said in the manual).

I tried several fans. All made this noise except a YS-Tech TMD-fan. The reason is that the TMD has the motor not in middle it is in the frame. Therefor it has a big mass and doesn't loose much speed then the power is off for a little time (in each PWM-cycle).

I thougt it would be possible to put a capacitor (e.g. 100...1000 µF) parallel to the fan to have a ripple rejection.

My question is:
Would it be dangerous for the 633?

Speed reporting is not so important. It would be only important for me to control the speed of the case fans.
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