Merlin New Book

[Windcrest77]

180kHz is a little dated these days.
300-1000kHz is quite normal these days and very easy to filter out.
The downside is that linear regulators won't do much anymore at those frequencies in sense of filtering. Even at 180kHz one has to check the datasheet.

I built Merlins XL4015 buck converter with linear regulator follower filament supply, seems to work pretty good and efficient. Designing a PCB for it next. I'll have to look at the output on the scope to see if there are parisitics. But the utter convenience of precision bucking really makes things cooler than dropping all that voltage in the linear regulator alone with way less power loss.