I had this same problem, after "upgrading" my 600rpm motor with the 300rpm kit. A LOUD snap when turning my motor off and forgetting to mute my preamp, and a lower level pop, even with the preamp muted. The situation could be mitigated, somewhat, by SLOWLY operating the switch. Either way, I found the situation completely unacceptable, so finally I got around to soldering in a snubber circuit.
I used a five watt 180 ohm resistor, and a 630V .033mF film cap I had lying around.
For those of you who may not know what a snubber is, in this application, its just a capacitor in series with a resistor, wired in parallel with the switch. Problem solved.
I used a five watt 180 ohm resistor, and a 630V .033mF film cap I had lying around.
For those of you who may not know what a snubber is, in this application, its just a capacitor in series with a resistor, wired in parallel with the switch. Problem solved.