Just ordered a NW one, thanks.
James, there are E2 and E4 XHP35’s, and theoretically an F2 but I have yet to see it. The D4 is a lower output bin.
Edit: I see you were talking HI, I don’t use HI for a smaller light as throw won’t be a factor anyway and lumens is where I want to be. The D4 HI shows clearly that even Cree loses 2 bins of output when removing the dome. 
For the wattage people, both the D4 HI and the E4 HD are capable of 13.488 watts at maximum rated output, but the E4 HD is making 1712 lumens as compared to the D4 HI’s 1483. Same wattage, serious loss in output. Pushing them beyond factory specs only increases the output spread.
Edit II: Once again I see I am missing a point, this light comes with an HI emitter. So their claimed 1300 lumens is actually dang close to Cree’s stated max of 1483 emitter lumens. Interesting. Ok, sorry I keep missing the relevant details. I will still point out that the U21 was a tweaked driver design and it was having issues, failing. I am hearing that Manker stepped output down and according to the Manker website the U21 is now rated at 1300 lumens and 24Kcd, same as this light. This was from looking at both the Manker website and the Gearbest website on the Utorch UT02 yesterday afternoon.
Is this light using the D4 bin?
Code for NW please.
Forgive the ignorance, but……
I am not a modder by any means. Soldering skills are very low level.
- How hard was it to add that resistor? (there a simple way to describe it)
- Have you run any extended tests on it in that setup to evaluate increased output? Poorly managed heat? Shutdown? etc
Thanks for any input.
This light definitely use E4 bin maybe even 5700K as I said earlier tint is much better then usual HI emitter with 5000K like XPL HI U6 3A
Thanks Dale for bringing that up, and you are right about U21 driver, all review samples we have been able to see, came with different driver then the one in serial production…
The difficult thing was to solder again the switch & led wires after you put the driver inside again (4 really small wires) . Resistor needs some skills too , it’s 0805 or 0603 size .
I will measure output when i have time .
Exactly . Production driver has a little lower output .
Yeah…I definitely don’t see myself doing that then. Anybody in the U.S. want to offer an affordable modding service if the mod proves significantly beneficial? 
My U21 review sample measured at 1345 lumens stock, very close to the 1,300 claimed. As far as I recall, it was always rated at 1,300 lumens. Mine was even an engineering prototype sent out accidentally that had a small bug in the firmware, never released. My driver died quick, as well as one other I'm familiar with.
According to my notes, back on June 11th, I rcv'd it, dropped in a EFEST 5200 cell @4.20V, and measured 5.44A at the tail with a clamp meter, 1,345 lumens @30 sec, and 127 kcd measured at 5m. Output actually held steady for the first 30 secs - no drop at all.
I am supposed to be testing the 2 lights side by side soon, of course I’ll be reporting my findings ASAP.
Thanks Dale 
Groupbuy time has been extended too .
Tom E numbers for the U21 on turbo pretty much matches other’s people measurement, between 5 and 6 tail amps and slightly above 1300 lumens at startup, NikolaS 2,57 tail amps and 1240 lumens at startup is twice the efficiency of previous U21 data, one thing is sure NikolaS’s UT02 doesn’t use a D4 bin (wich i was under the impression was the bin in the U21 unless that was the XT11GT)…
giorgoskok when is the new groupbuy deadline date?
Ordered NW, thanks!
I don’t know if I should say welcome to BLF , one post since may 2012
Mine arrived today, I think it ’s a great little flashlight fit and finish on the one I got is very good. UI is good one click from off is low, long click is last used mode and you can memorize turbo. The amp draw on mine is 2,67A at the tail. It’s a shame with the low amp draw, because it has a lot of mass and should have been driven harder. The only fault in my eyes is the amp draw, the rest is perfect, if they had advertised it as a 1000 lumen flashlight I would have been a happy customer.
Thanks George for setting this up.
Just ordered another
Jaxman X1 XHP35 HI 0,6A @ the emitter (left) Utorch UT02 turbo (right)
The tint of the UT02 seems a bit green to me ( I am a tint snob )
Is it just me?
It has been said that some 2.6A at the tail yields 0.70A at the emitter for ~1300 lumens, right? So if Tom’s light was pulling well over 5A at the tail and still only making 1345 lumens, what gives? Sounds like two different lights, the one having a 12V XHP-35 and the other having an XP-L HI… or so it would seem.
Funny, the little BTU PK26 on turbo draws more amps, resulting in more lumens that these bigger lights. My PK26 draws ~7.0A at the tail (clamp meter) and the XHP35 HI does about 1,650 lumens @30 secs.
I’m really not understanding the comparative amperage to output in some of these lights. 2.13A at the emitter yields over 2000 lumens. I’ve seen 3.13A at the emitter making right at 3000 lumens. Perhaps it’s the smaller diameter reflectors in these smaller single cell lights? Or is the efficiency really low on the boost drivers?
Can i have code for one nw please