Can we get some photos of the driver? Is it a 12V 2A driver?
Yay! Canāt wait for the 519A, and Iāll be putting in an order, or 4.
Speaking of drivers, I have a KR4 with SST-20DR that I rarely use. So Iām thinking a changing emitters so it getās used more often. Am I correct in assuming that a new driver is all I need if I want to change this to 519As? Emitters I already have and can just reflow onto the existing MCPCB right?
I assume the same linear driver is used with the FET disabled, you should be able to swap the leds without other modifications, only flashing the FET enabled firmware if desired.
Ah that would be great. I havenāt really looked into it since so many other projects always seem to pop up, but Iāve always assumed it was a dedicated driver due to the lower Vf. But purely based on an unfounded assumption. Have the flashkit, so this should be easy to tryā¦. soon-ish 
Edit:
Itās a white PCB marked with a blue dot. For comparison, a KR4 with E21As does not have the blue marker dot. Indicates different firmware? Or difference in resistors?
Just got my DM1.12 (SFT40 + 219b 2500k) and 2 channel D4v2 (W1 + LH351D 5500k). Love both of these lights, they just need some firmware alterations. The D4 turbo definitely needs fixed.
Did you try the standard 9.3 target too? EDIT: all K9.3 builds are broken according to the latest revision of Anduril 2.
Are we missing much by using the regular 9.3 target that the light came with stock vs the tintramp version?
3 clicks to unlock to off.
Itās great to see the boost drivers!
How low is the level 1, lowest brightness, with this driver compared to the linear 7.5A linear driver. Iām asking for a quad d4v2 e21a specifically, but Iām also curious about other emitters (if thereās any difference).
Lowest mode of boost driver vs linear driver?
Lowest mode of boost driver vs dual channel driver?
the boost and dual channel drivers have comparable moonlight levels, typically around one lumen in the six samples I have measured.
The linear drivers are typically much lower, closer to 0.1 lumen in the samples I have measured.
When can we expect the 519aās to be available? The new boost driver seems to be a perfect fit for themā¦
The 519A LEDs are supposed to be delivered to us one week ago from the supplier, but the tracking stops updating due to the shipping issue (very few flight service to China due to the COV-19), thus Iām not quite sure when they can be available.
Which CCTs of 519 A have you ordered?
Thanks for the update, Hank!
On a related note, do you have any plans to ever offer the KR4 in brass? An antique brass KR4 would look incredible.
sm453 M450 R9080
sm353 M400 R9080
sm273 M350 R9080
sm573 M450 R9080
Hey, good news! I heard back from someone in US sales after my contact got bounced around other countries for awhile. They will, indeed, be producing an SFT-20 white in the future, but likely sometime in 2023. They are focused on the money makers first (larger dies like ā40 and 70) and will be ramping up mass production of the SFT-40 and SFT-70 this yearā¦.then the SFT-20 will enter the picture. Iāve asked if he has any idea about bins and such, or perhaps a prelim data/introduction sheet, but it may be too early for any of that. But itās on their radar and plans are in the works just wasnāt quite important enough to put the resources into considering market and world conditions lately. He sounded somewhat aware of the general flashlight market but was interested that the small flat Osram emitters have seen some popularity.
If I hear more or get some numbers/sheets, Iāll update then.
KR4 boost driver with 519A, This will be my first high CRI light from Hank 
ā¦ always went with the higher lumen choice before.
Sounds interesting! Please ask also if they plan to produce a 4000K 95 CRI SST40 or SST70 because flashlight enthusiasts are waiting for that, too.
A good idea would be to put together four SST40 led dies and make a 7070 led with 95 CRI.
Thatās better than I was expecting based on some reports, but still sad we donāt get a ~0.1 lumen moonlight with the boost driver. That makes it a harder decision, better runtimes and sustained output vs. better low modes (and FET turbo).
It seems like the next logical development would be to improve the boost driver to get a lower moonlight. High efficiency along with excellent low levels would be the ultimate light in my mind (never really needed the short lived FET turbo). (It would also be nice to get lower levels with the dual channel drivers as well.)
One option might be to burn off some of the power coming out of the boost driver at the lowest level in a small variable resistor. Obviously the runtimes would be worse doing that, but for the lowest modes runtime isnāt really whatās important (since they are so long anyway), what matters is keeping the light level low enough to preserve night vision, not wake up your partner, etc. I donāt know the details, but I think the SP10 Pro does something like this where it has a really low moonlight mode, but itās not very efficient in that mode.
Another option for existing lights might be to add an firmware mode to make the aux lights easier to adjust. e.g. a ānightmodeā where you step through low aux red~~red+green>whitehigh aux red>red+greenwhite>level 1level 3~~>level 10. Obviously not as nice since you wonāt get the superior primary emitter light, but might do the trick. If I get some time, I might try coding up something like that myself.
Thatās a great selection! It might be interesting to get some of the `50e` bins as well and offer both as options. For example, sm5750e, sm4550e, sm3550e, and sm2750e. In theory those would be rosier on average - for people who like that. I personally like things more neutral, and itās better for tint ramping lights, so Iām happy with that initial selection. However, the `50e` bins are likely really interesting to some as well, since it should make for a rosier emitter without the need to dedome.
This has probably already been answered, but the thread is 169 pages long and I havenāt seen every single post yetā¦
Does the boost driver support a lighted switch on the D4SV2?