I only have 3 of the drop-ins and I do not hear any buzzing at low in any of the lights. I think you may still have a problem if there is an audible buzzing.
Can someone with more experience with these drop-ins weigh in if this is not an uncommon problem?
It is a common phenomenon for budget lights. Nothing to it... If you don't hear it, put a black t-shirt to cover the front and put your ears beside the T-shirt. I can guarantee you that you will hear it clearly. :)
Probably 98% of the premium lights would not have that though.... And I know 1 budget light, the $29 Xeno E03, does not have that. The $14 UF-2100 doesn't seem to have PWM but it does....though it's at 4.75kHz. It's measurable, and if you put a black t-shirt you can hear that 4kHz squeal.
The light is supposed to be hitting the black surface and when it hits it, the air expands. When it is OFF, it does not expand. Do this 4000 times a second, you hear the 4kHz squeal. You can put a black wallet in front of it and you will hear that.
Thats odd. I wouldn't think the light is strong enough to produce audible vibrations, but it does indeed work. I'm going to have to record the sound & take a look at the frequency sometime.
Those that normally hear buzzing (without a black shirt) can try coating the inductor or whole driver with epoxy. Sometimes the inductor vibrates & perhaps other components as well.
PWM is a weird thing..i'm not sensitive to it but it's weird to see water flowing or shaking your hand in front of the light..my zebralights and sun v60c are current controlled and much more efficient at lower outputs..budget lights have their place but everyone can appreciate the higher end lights when you start to see and understand the differences..
A driver swap is the easiest way I know of. I swapped out the driver in my MF/UF drop-in with one of the 3040ma 7135 based drivers from KD and the PWM banding in medium and low is gone.
Yup this is a common thing with budget drivers, pwm and also could be inductor whine. Did someone say Xeno is a "budget" brand? I would throw Xeno in with Fenix, Olight, Jetbeam and such, so not a budget brand to me.
Sorry, I'd say that Xeno E03 XM-L is a budget light. A very good one. I have 3 Xenos and 2 E03s. NW is 31 and CW 29. Why wouldn't that be budget enough? A C8 XM-L of good finishing quality (of course that is bigger) runs about $25 cheapest. A Uniquefire G6 XM-L (great finishing for the host!) is 24 bucks and has PWM.
As for the brand, Xeno does make good stuff, but there are small differences. Stuff in the details like the lens (check out any SWM and you'd know why), heft of tailcaps etc.... And also a very big differentiating point is the UI. Shadow lights are also very good lights in their own right.
Yeah I can see how the Xeno E03 would be considered budget, but barely if that...though I would say Ultrafire and generic 1AA lights that cost $12-$18 more of budget lights in this catagory.
Often in this forum, the folks would recognise 2 types in the budget cat : Good budget lights and CCC. Eg my Ultrafire C3 metal tailcap is 19 bucks, 1xAA and is a good budget light. There are like 10-12 bucks AA lights that usually people would not mention.
My $9 TK703 is a good budget light as well...
PS. Even TF/UF have been producing some good and interesting stuff lately as well...like the Ultrafire T60, TR-3T6 / TR-J12.
