Anybody used one of these yet? In What? What Driver? How hard driven?
http://intl-outdoor.com/noctigon-xp20-mcpcb-cree-xpe2-r4-1c-led-p-771.html
That must have just come out in the last day.
that one wasn't there on the IO site yesterday, nice!
I have used the xp-e2 for several mods (eg, in a sk68 mod) (the 1D tint that Illumination Supply sells), all dedomed because that is what you want the xp-e2 for: minimum die size driven hard for maximum throw. If throw (or a bit less exteme: a tight hotspot) is not the goal, you should use the more efficient xp-g2, can be driven harder as well.
The maximum output (on a Sinkpad), as measured by match, is reached at about 2.5A, so it is counterproductive to go over that.
Thanks, got 2 coming …
this is good news! so far the other places that have this charge for shipping to Australia. Nice to have a free shipping option
Upon dedoming you would expect this led to come out a bit more yellow than the 1D tint from IS.
There's no other places that have the R4 bin
I hope they’ll stock bare emitters because that’s what I need in my Nitecore D10.
If it is released to the chinese market, it will likely to show up at other sites, no? No doubt there will be bare emitters soon
I have used several of the ones IS sell mounted on Noctigon in various lights. Some de-domed.
In normal sized single emitter lights Id take XP-G2 over XP-E2.
Just for comparison, here is XP-G2.
In not into pencil beams, so I don't find the XP-E2 in a larger reflector lights to be useful. Especially not if its de-domed. Tint wise id stick with the ones from IS for de-doming..
XP-E2 in small reflector lights makes sense for me... :) Especially lights using 1-2 nimh batteries where current is limited. At low currents output is almost similar to XP-G2 but in comparison it throws much better due to the smaller size.
I plan to stick several XP-E2s in a 5 emitter SRK sized reflector. Ill mix in an XM-L2 and do some tint-mixing just to make it interesting. Im curious how that compares with a similar sized reflector using XP-G2s or XM-L2s..
I installed the CREE XP-E2 R4 1C LED on Noctigon , dedomed, in the Uniquefire UF-T20 from wallbuys.
The flashlight came with a XML T6 emitter, and the tailcap current was 2A.
the driver :
The new emitter was installed also with much thicker wires.
The problem is that, after the emitter swap, the tailcap current decreased from 2A to 1,3A .
Is it something wrong with the new emitter? Why I see this current drop?
I need to drive this emitter at 2-2,5 A.
It’s probably direct driven so don’t forget that when Vf rises you get less current. 2A is nothing for XM-L (so Vf is low) but it’s also 2x more then XP-E2s maximum current (but still 1,3A means very high Vf).
At 2A, the XM-L2 has a voltage of 3.2V (XM-L even a bit lower), the XP-E2 is 3.45V. So the driver has to push harder to get the same current through the XP-E2, and a direct driver does not do that. Best perhaps is to use a lineair driver, like a NANJG 105C (you can get one with 7 chips at Fasttech, giving a nice 2.45 A), it adjusts the voltage to provide a constant current regardless of the voltage of the led.
Linear driver is just a limiter, it regulates the current as long as battery voltage is higher than emitter Vf+0,1V. It won’t boost the current. And Cree specifies only typical voltage but it varies, sometimes by a 0,2V or more.
Thanks for the answers guys, it seems logical. Now let`s shop for new drivers.
What a little beast is this XP-E2 emitter 
A 7135 drops around 0.12-0.15V at 380mA rather than 0.10V