No, it was a GA3, right on the BBL. That’s what Mouser told me anyway.
The problem for these LEDs is that they tested very slightly below the BBL, or on the BBL.
That means while an LED might pass Luminus’ binning tests, it might not for us flashlights.
Actually it is slightly above BBL even without reflector or optics. Once you add the reflector or optics and/or run it on low output, it will always be above the BBL, so it is not like the 3000k HD2 tint bin that is always below the BBL. GA3 tint is supposed to be entirely below the BBL.
This is really useful data.
I was really hoping the FA3 bin would be below BBL even at low power, but it looks like it still isn’t. Great tint at higher power though. I should put some on a MCPCB to see how it looks during use.
Would it be safe to use SST-20 with a FET driver in 18650 light?
They are unobtainium apparently. TA keeping his stash secret for production lights 
A single SST-20 fries at about 7A, so triples or quads are your best bet when using them with a FET. Otherwise with a medium drain cell like NCR18650GA and a light that isn’t SUPER low resistance a single one should be fine, people have been using them in the D1S and other FET lights.
Texas_Ace had his supplier send me a few, totally out of the blue. I’m not sure why. I don’t have good test equipment like maukka does, and I’ve never actually reflowed LEDs onto a MCPCB. But perhaps it’s time to start.
Based on what I have seen in maukka’s review for CRI and output, the high CRI SST-20 is best used at around 1.5-3.5A as max current. Under 1.5A, tint is not pushed enough to or below the BBL, above 3A, but especially above 4A, color rendering for deep red (R9) starts to get somewhat worse (still above 60), and regarding efficiency, my choice is also max 3.5A, because when the current is raised above that, the gain in output is not really perceivable, but both heat production and battery runtimes go linearly worse - and above 5.5A, probably LED will degrade much faster during usage.
So if a FET is considered, a single emitter configuration will probably fry the emitter, unless other specific circumstances get the current down enough.
(But I would happily take a look at those posts, which confirm, that single emitter FET thrower builds are possible).
Thanks to those of us who actively attract regulated drivers there are now more of them. I recommend you to stop the anathema of FET drivers and start thinking higher. Believe right, there are no limits.
Well, I was worried that SST-20 and FET were not a great combo. But it was at the edge of my understanding of the stuff so I was not sure. Thank you all for the confirmation.
Yeah, that’s right.
FET+SST-20+low resistance circuit = poof. Magic smoke is released.
These newer SST-40/8A high current linears Simon requested being made feature an Atmel MCU onboard. Playing with the sense resistor also helps. I will use one as it comes for a White Flat 2mm² in a C8 but inside an S2+ with LH351D I will replace the stock R005 with an R010 (4A) or R010 plus R050 (4.8A).
They have solder mask down at the spring base. Can fix that with Cu sheet + thermal glue but it is another bummer for my spring bypass technique. 
:-)
Since your FET-driver crusade started, I never stopped thinking higher, and believe me, my thoughts have no limits. Unfortunately, reality does not listen to my wonderful thoughts and existing well-regulated drivers are often bulky or expensive, or at least have a medieval user interface that after I started using TomE’s and Toykeeper’s firmware, I will never tolerate.
So I keep thinking, and using my pleasant and convenient BLF-A6/bistro/biscotti/Narsil/Anduril flashlights, keep not noticing that regulation is not perfect, and in the meantime wait for the small and still powerful affordable current-regulated driver with TK-quality UI to appear from some heaven.
Same here. I love the idea of linear FET driven lights.
Power density is great.
Efficiency is slightly better than with our standard FET+1 or FET+N+1.
I don’t think the hardware is inherently expensive - though I am uncertain here.
Flexibility of adjusting current to match one’s needs is great. F.e. I’d love to PWM SST-20 with 2A at moon and limit to 4.5A at Turbo. Wouldn’t go particularly low but it would have good performance and consistently great light quality.
But such driver is not available.
There’s Texas Commander but it never took off.
There’s Lexel’s driver but it’s in progress.
There’s Led4Power driver but it lacks good UI.
There are several other drivers that have, yeah, medieval UI.
So for now we need to settle at sub-optimal choices. Like PWMing a FET to reduce current. Or adding large banks of 7135s. Or adding resistance. Or using only well-matched cells.
I really hate the state of affairs. But it is what it is and I am unable to do anything about it.
Reality does listen to your thoughts, albeit not everything you think is something you believe.
You allowed yourself to become addicted to those firmwares. Despite being your respectable choice, as any other addiction that is bad. And those last words I left in bold in the above quote are terrible.
Cheers :-)
In real life I can be be very tolerant, as that is often needed to operate well as a human being, but in my hobby I allow myself some plain intolerance at times 
Non customizable UIs have slowly became intolerable to me… as well as Low CRI, gritty threads, mushy button, ringy beams, and so on… I’m a flashlight integrist 
Nah, I am not keeping them, I can’t get them myself.
I tried yesterday to get my hands on the FA3 but the manufacture is holding them with an iron grip. All I managed to get were a few samples for myself and a few others.
I can get FD2 SST-20’s but I don’t know if it would be worth the hassle as I would need to get 500+.
Consider it a peace offering after all the bugging you about firmware issues lol.
I knew you like high CRI LED’s and tint mixing so when they said they were sending you a box anyways I asked them to send you a few of these LED’s as well. I think they were supposed to send some FD2 as well?
I am actually going to try tint mixing a 2700k from KD, the FA3 sample I have + a 5700-6500k 70CRI SST-20 in my EDC with a 10511 optic to see if the final tint can get that rosy range we love so much.
I did this with XP-G3’s before and the final tint was surprisingly good, I ran that setup in my EDC for the past 2-3 years.
I’d be in for 20 if by some chance a group buy was put together.