Ordered Kr4 e21a,will order Ti Kr4 e21a(hopefully Ti body with copper head design) as soon it become available.Thanks for your time answering our questions.
I'm just getting deeper into this topic, so please excuse me if this is a FAQ:
I'm trying to wrap my head around the whole "no FET" business. If understand this correctly, a common driver design is using a combination of linear regulators for better efficiency on lower brightness levels and a FET to switch a pseudo direct-drive straight from the battery for the top end. So when you're referring to "no FET" does this mean that linear regulators are used all the way up to the brightest output level? Are there physically no FETs populated on the PCB or are they bypassed in firmware?
Are there schematics available for the driver used in the KR4 or similar designs? I want to understand this!
DHart, it is not just the CRI to be considered. It is also the tint. The E21a offered by Hank are all under or on the BBL, if I am not mistaken, while the SST-20 are above it. Also, the SST-20 have a notorious tint shift.
People call FET what is infact direct drive, most imagine a buck driver does not have a FET or for that matter it can have more than one FET easily after all it is a MOSFET.
You do not need a combination of linear regulator to regulate current ( maintain it constant as long as the Vin+voltage drop is above VF) just one linear regulator is enough and a FET is needed to achieve that.
A linear regulator is a regulator, not to be confused with direct drive that as a resistor in series just to limit current like it was done several years with flashlights, then they added a FET in order to PWM it for having modes.
Thanks for the info. I have a KR4 with the SST-20 3000k 95CRI and the tint looks awesome to me!
I don’t understand what the BBL reference is, though. Can you elaborate on that.
And, as for notorious tint shift with SST-20, does that mean the tint changes over the life of the light? Or the tint shifts while using the light?
So, I take it the SST-20 3000k 95CRI is considered a poor choice of emitters? I like my KR4 with SST-20 3000k 95cri emitters so much that I ordered a D4v2 and a D4Sv2, with the same 3000k 95 cri emitters, due to arrive from Hank next week!
Thanks for the education. I’m one who does prefer rosy over green, but fortunately, I don’t see any green going on with the KR4 SST-20 3000k version, just a delicious warm, candle-like color. In fact, I use it as a bedside candle-mode, flickering ceiling bounce light, every night! Fantastic for that use.
I take it the E21A is a noticeably nicer emitter (I like warm color temps) than the SST-20. I guess I jumped the gun on ordering my D4v2 and D4Sv2 lights with 3000k SST-20 emitters. :person_facepalming:
Oh well, I know I like the SST-20 3000k.
It is true that in warm CCTs, like the SST-20 3000K, the green is not very apparent as it is covered by the yellow warmness. Moreover, the tint tends to shift towards pink at higher power levels, so the most green is at ther lower end where it is even harder to spot. I got an SST-20 D4V2 Ti, thinking Hank had a below BBL bin, but I was wrong (my information was very much outdated). I liked the tint and only saw any green when compared to Nichia 219b sw30. As I liked that option far more, I modded the D4V2 Ti to 219b sw30 (3000K) and flashed it with the Nichia firmware. I cannot describe how happy I am with it.
If you have modding skills or can get someone to do it for you, it is well worth it. Lower output, of course, but soooooo much lovelier. So, no, you did not jump the gun. D4V2 will not be made available with E21a, as Hank said. SST-20 3000K is the best option for a light that is very much worth it.
I have four Nichia 219BT SW30 3000k emitters… perhaps I should send the D4V2 off for a transplant? Does the Carclo lens need to be changed when switching from SST-20 to 219BT? And is flashing with Nichia firmware necessary? Does that eliminate Anduril? I really love Anduril!
Lens doesn’t need to be changed, and the Nichia firmware just limits the FET so you don’t burn your emitters out. Still identical in all other aspects.
It’s not very fun putting it back together after an emitter swap….