LED lights and "inductor whine"

I recently purchased a Fenix L1D Q5 (in olive) and really liked it's output, but I had to return it due to the "whine" noise it made (on two of its' levels). I just felt this would be annoying to listen to, especially in a quiet environment. I've read that some people have had an issue with "inductor whine" on the Fenix LD01. Is this just a random issue, or something you have to ultimately accept with multi-level LED lights? Is this an issue with any Surefire lights? (I plan on purchasing a Surefire light one of these days..) Thanks for your help!

Very little issue with my LD01, I have to actually place the body adjacent to my ear canal to hear anything, and my hearing is probably at least average. They considerably upped the PWM / inductor frequency for the LD01 due to that issue with the older L0D, perhaps it's higher than your L1D?

All my multilevel SF's have zero noise at any level, they use a resistored tailcap to drop the current down. The newest SF model (LX2) uses the tailcap resistor to signal the drive circuitry to change outputs, my guess is that this doesn't involve PWM, but perhaps someone who is more familiar with the latest SF circuitry might chime in here.

Inductor whine is not an artifact of PWM, it's an artifact from the inductor... Which in the simpliest sense is for voltage manipulation.

Most multi-levels seem to have some whine if you're ears are sharp enough. Mine aren't.

Geoff

I have good ears. Some of my lights have the whine others don't. Seems hit or miss.