Found: The quietest, lowest EMI residential dimmer switches

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Joined: Tue Feb 02, 2021 1:56 pm
Location: Detroit, MI USA

Found: The quietest, lowest EMI residential dimmer switches

Post by Sundown »

Hey all,

I've been on an EMI journey lately given that my old bedroom home studio had some ground loops and EMI buzz. When I recently mapped-out all of the breakers and saw which rooms were sharing circuits, some of the root causes became clear. With the new setup I'm building in my basement (shown here) I want to make sure I'm getting the cleanest, dedicated power and minimizing EMI to the furthest extent possible.

In this journey, I've learned what many know already: Dimmer switches are the enemy. A powerful LED dimmer switch anywhere in the house is enough to generate a lot of EMI noise. My first step was to get rid of all dimmers that were unnecessary, but in the few cases where a switch was absolutely needed, I wanted to find the unit that produced the least EMI.

I didn't have the advantage of an oscilloscope so I used an AM radio and a simple power source, dimmer, and LED downlight setup. The units I tested from Lutron, Leviton, and Eaton were garbage. The Lutron Diva in particular could qualify as a radio tower. You can pick up the interference several rooms away with even one of those units in the house.

The unit that produced the least amount of audible interference (by far) was the Legrand/Pass & Seymour Radiant switch (shown here).

I have no connection to the company, so this is just information sharing from my own journey. This is also not the most scientific or precise approach to comparing dimmers, but having found no resource or article that compares dimmers in this way, I figured I would share my own findings and experience.

The best outcome is no dimmers at all, but if you have to put one somewhere in the house, try the Legrand/Pass & Seymour Radiant switch.

All the best -