Or lower, too. Lower frequency will be less likely to make parts this size move in a way that makes audible noise. Like if you take a poly done tweeter and send it a 200hz signal, it will move but not enough to make a noise you can hear.
The fast PWM in STAR works well with the K4212... I accidentally did that when I was testing the momentary at first. Forgot to switch it...the low modes just weren't nearly as low, high modes were the same. Never tried it with the 70N02 but it may just work as well.
The inductor/etc. seems to definitely add a lot of squeal depending on the size and as Comfy has noted, the size of the capacitor. The problem is that a large inductor + large capacitor = not enough room!
I’m about to put my very 1st scratch built driver together. I’ve got the 17mm FET board, V1, and all the components. But now I can’t seem to locate what goes where and in which direction. This is pointed at which resistor is R1, and which direction does the diode go? Is the line on the diode the positive?
For the diode, best to check the datasheet for the specific one you have. They don't all follow the same rules.
Pics or it didn’t happen 
Tom, I'm still young and I need a headlamp strapped on and glasses as well. My hearing is still good though! 
You really don't want to see this ... Can't believe I'm planning on playing softball again this year - first game this Sunday morn. These guys were begg'n me - dunno why, accept maybe for a few laughs as I stumble down to 1st base. Actually my reflex's are still pretty good - been playing ping pong and can still keep up with the quickness. I pitch, so reaction time is extremely important against these roid rage kids and their shaved bats... (ooops, off topic). Well, bats that are high powered and mod'ed -- sounds familiar...
Sure you can… just don’t shower or change your underwear for a couple of weeks. You’ll be smellin’ big time in no time. J)
Welp, my old standby version of luxdrv doesn't work on the 17mm FET board (sometimes a half-press gives two mode changes instead of one, sometimes none at all), even though with the same components on a 105C PCB it works fine. I think I need a nap.
Based on the components as they were on the Qlite. I wired it as it seemed best and the DMM shows power, but no light. I’m at a loss.
Only to others though 
"Based on the components as they were on the Qlite. I wired it as it seemed best and the DMM shows power, but no light. I’m at a loss." which board?
Matt’s first FET board, the one with no ground pads on the spring side.
Can you post a photo of both sides and I can tell you if it's a hookup issue or if there is (I hope not) a potential trace issue?
Mine acts like the early attempts when the code didn't work right without an added capacitor. Just weird, unpredictable mode changes. Sometimes it even does a strobe mode that's not there. Sometimes it does weird patterns of blinks like morse code. Checking the board with the meter, the cap is connected to where it should be.
Check the Vcc voltage of the MCU to make sure the diode is not connected in reverse.
If the diode were backwards it wouldn't work at all.
The diode seems to be compatible with what comes on the 105C, I get 9 blinks in luxdrv's battmon mode from a cell that measures 3.87v, close enough for me.
Now that I think back, on the big 46mm version, mode changing went goofy as well when I was testing without the big 470uF cap. I'm using this one, should be correct right? Does it just need one rated higher than the 105C's original?
Comfy, I think that capacitor is correct, I think I've seen mentioned that the stock cap is also 10uF. This one should even be better since it's an X7R from a name brand... dunno what's going on there. You could try and stack a second cap on top of that one to see if you get any better results.
Pics of your build please?
Diode backward?
What OSHPark board are you building the 15,17, or SRK?
Comfy…is that the 17DD initial release the one w/o the ground ring on the battery side…might not be getting a good ground (floating ground)
Looks to me like he's got a wire soldered directly to the FET pin for ground, is that correct?