Thanks nocturne and BurningPlayd0h for your replies, but I don't care much about PWM, my question was more tintwise.
The E21A version is rated at 1200lm, whereas the 219C is 3000lm, which makes quite a difference. Not that I am in the "lumen race", tint and beam shape are more important to me, so how do these two LEDs compare in terms of color and hotspot vs spill?
Whether you care about PWM or not, it is useful information to know that the KR4 effectively uses two different drivers, at least the implementation is drastically different, and, in fact, one is likely more efficient than the other, and it isn’t necessarily the brighter of the two that is more efficient, because the emitters also play a role and have their own efficiency aspects.
I can’t answer your question directly as I have not seen either emitter’s output, but I do know that 3000Lm is only 40% brighter that 1200Lm, and anything less than 300% brighter is going to only be negligibly brighter, even if you can tell the difference in brightness, because for a light to appear twice as bright as another to human eyes, it needs to actually be 3 times brighter.
If the best tint is your goal, I can only help a little, and only by deduction and transitive law say the Nichia E21A tint is superior to the tint of Nichia 219C, generally speaking. To explain this, from what I have read here at BLF, the gold standard of tint among the tint mafia is the 219B 4500K, and this is apparently superior to any version of the 219C, again, tint wise and generally speaking. Yet the tint of E21A somehow competes with the tint of 219B. So if X is competitive with Y, and Y is better than Z, then X is better than Z, iow the transitive law applies.
I also suspect that if beam shape is another goal, then you should be made aware that a single emitter will have superior beam characteristics to triple emitters, and triple emitters will have superior beam characteristics to quad emitters. It might make more sense to compare single emitter beam characteristics, but become vastly more complex comparing 4 of one emitter to 4 of another, or it might not make sense to suggest that if one emitter has better beam characteristics than another, that anything at all can be said accurately about 4 of one emitter compared to 4 of another. I could be mistaken, but I think the beam characteristics in a quad are going to depend more on the optic than the emitters themselves.
I know none of this is what you want to hear, so I’ll just tell you what I think you really want to hear: if you put weight on brightness over tint, then get the XP-L HI V3 3A 5000K, because it is actually not a bad compromise in tint for the 4300Lm you’ll get out of it. I think maybe your attraction to Nichia 219C may have to do with an assumption (that I have seen at least a dozen times already) that the 219C tint is good because the 219B tint is good, and this simply doesn’t follow. Most tint snobs here, from what I have read and have had explained to me, aren’t all that impressed with the 219C.
That said, I personally am curious about the 219C, and from the beam shots I’ve seen, I think it is very attractive, and I intend to acquire a light with 219C no matter what the finely tuned tint tastes are of those that best know tint, and I’ll certainly choose it with a constant current driver over one burdened with PWM. Over just a handful of years considering the opinions of those that know drivers best I have gleaned that constant current drivers are more efficient than drivers with PWM, so this will help mitigate the fact that the emitters with the best tint are the least efficient emitters. Plus, it is hard not to notice that PWM kind of sucks.
I hope this helps.
I just got a KR4 and also a D4v2 with Nichia E21A (selected different color temperature for each). I notice they do not have PWM on all levels.
I’m wondering about the “D4v2.5” you mentioned “CC driver by request” = what does this mean?
Does it mean that if ordering the D4v2 with say XPL-Hi LED, then it will use the normal FET +1 driver and will have PWM on all levels except the “1” (0.35A) and Turbo.
But if I want the “CC driver” with an D4v2 (or KR4) with XPL-Hi, then I have to specifically ask Hank to install the CC driver, which will have NoPWM up to 5A and have PWM only when using higher levels (uses FET)?
Thanks nocturne for this very informative post.
Re. 219C, here is what Maukka said in his Astrolux S43S (4x219C) review:
With regard to tint, the beam is very even. There’s some artifacts at the edges, which may be because the optic might not sit perfectly on the LEDs. This was the case with the Astrolux S42 as well. It’s not noticeable in actual use though. I haven’t seen this with lights using Carclo optics.
and:
Some modes between the 7135 and FET get a bit greenish in tint, but low modes and turbo are very nice
In his conclusion:
The tint consistent throughout the beam and neutral on most modes. It still doesn’t achieve the rosy beauty of some 219Bs, but can be altered using filters
Re. brightness, I don't think I will ever need the extra 40% over 1200lm, I assume the latter is enough to blind an assailant and impress friends.
Re. beam shape, in fact I like a very smooth transition between the center and the edges, like e.g. on my Zebralight H51Fw. As far as I understand this can be achieved whatever the LED using the 10623 optics or d-c-fix film.
I made a poor assumption. Throw has a distinct cohesive beam, but with floody lights, and especially if using a decent diffuser or certain optics, the beam sort of disappears and the light seems to come from no where, kind of a cool effect, wall of light. Both have their places, equally useful, equally valid when applied to what is needed. Since carrying the Lumintop FW1A, which is throwy/spilly, lacks flood, I noticed I prefer the mix of throw/spill and flood in the Zebralight SC5c II, the shallower reflector has a far wider illumination, but I can still throw the spot, within reason.
Forgot to mention the D4v2 w/E21A, yep that uses the CC driver with FET disabled.
You’re right on the money, you can email Hank and request the CC driver with FET enabled for any of the standard emitter options too.
I have two of KR4, black one with E21A/5K and gray one with E21A/4.5K. I would like to learn more about this driver. Does anybody have more information? I think it is a linear driver because it is with FET.
Also, does anybody have a photo of this driver?
Thanks.
Do you still have this light? Would love to purchase.
AFAIK FET + sense resistor for constant current linear driver that can be set to anything up to the max - 7.5A for E21A, 5A + fully open FET channel (PWM used between 5A and full turbo) for other emitters.
With delay.....Excellent review maukka 
Why does the short tube not allow use of the lanyard ring? Can I put a foil ring on the inner tail cap to allow the inner tube to touch?
It looks like the beam is much nicer without tint shift after sanding the optic. I will need to remember this for next try!
not same driver but most likely the same type of implemenation. Previously I saw loneoceans make a schematic of the K9.3, so this is probably the same but with only one channel.
I haven’t tested it myself, but that should work.
However some caution is in order:
Thanks for the response. I will try the stripped wire solution under the cap ring. The foil does work, btw 
I just find it odd that the small tube was built to not have any kind of lanyard solution. I’m afraid I may drop the tiny thing. I can now fidget with other things while out walking the dogs
Ok then, I bent a stiff wire just slightly larger than the bottom cap and pressed it in. Works perfectly with the small tube. Unfortunately it won’t allow the long tube to seat completely and the lanyard ring spins. It’s ok once I decide to leave it as short or long. I just find it odd that the Ti version will work with a lanyard ring with the small tube, but the Aluminum version won’t without mods.
I posted the D4v2.5/KR4 CC circuit previously here : Adventures in TinyAVR 1-Series - #91 by thefreeman
Indeed it’s the same except R3 which sets Vsense to 50mV (5A) instead of 90mV(9A).
AFAIK the KR4s and D4v2s w/ the CC driver still have the FET physically present, it’s just disabled via firmware by using the “noFET” version. At least one person has received a 3535 emitter light (where the FET should have been fully enabled) where it mistakenly wasn’t and a reflash solved the issue.
Can anyone tell me the r9 value of the Nichia 219C (SM503) 5000K 92+ CRI? I tried looking at the spec sheet and I can’t find it and don’t know where to look.
New to flashlights, I can’t find a 30q battery. It has 15a discharge rating. Could I use a 20a discharge rated battery. Same 3000mah capacity. It’s an efest battery. Is the efest k1 charger good? This is all in regards to the noctigon flashlight. I want to purchase one but unsure of what battery and charger to use. There is so many options. I was looking at a Sony battery very similar to the Samsung but also found this efest. I’m really iffy on chargers. Not sure what is good. All my other flashlights have usb chargers on the battery. I don’t wanna screw up and mess up a flashlight or blow something up.
Does anyone know where to source the very tiny rubber washer that stops the lanyard ring and the clip from rotating? I have broken 2 so far while changing configurations. Thanks