I originally considered swapping a LH351D into mine, but decided not too. Pushing a LH351D at 6 amps is past it’s peak and well past it’s sweet spot.
It probably won’t be anything revolutionary, but I ordered some 3V XHP50.2 to try in my SP35. I’m curious in the impact on raw output (lumens) and to see if it runs any cooler in Turbo (depends on how the vF compares vs the SST40). We’ll see. I know the beam will be ugly but I can’t help playing around.
Just curious, what is a safe sustained max current for an LH351D (assuming somewhat properly cooled)?
I tested tailcap current of SP35 (with a nearly full charged battery), and getting around 5 Amps max current consumption on Turbo mode (using a UT210E clamp meter), with a nearly full-charged 21700 battery. (although I’m not sure if the power consumption will vary depending on battery voltage for the SP35 — since it uses a buck driver.)
I believe around 5 amps, that is where Wurkkos’ FET powered LH351D lights max out also.
And with a buck driver, the amps at the LED can/will be different than what you see at the tailcap. It will vary based on cell voltage.
And yeah, at least based on maukka’s test, I’d prefer 5 amps max with a “sweet spot” around 4 amps.
I got 2 units SP35, ordered at slightly different time (from 2 different official Sofirn online stores).
Was wondering why their beam pattern has a bit of difference.
The units looks physically the same, nothing that I can visibly observe that’s different with their head or reflector (I haven’t tried to get out their reflectors to take measurements).
As can be seen, the head/reflectors look the same:
but there is a slight difference in beam pattern:
The left side is a slightly newer SP35, while the right side is the earlier SP35.
The left side SP35 has a more solid hotspot, whereas the right side SP35 has a smaller hotspot, but the hotspot (or is it the corona) is bigger.
Interesting! I wonder if this is a consequence of the updated reflector after the first ~100 units
Perhaps the curvature is just slightly different to focus the beam better.
It’s difficult to tell from the picture, but is the reflector on the right side sitting further down on the centering gasket?
Thanks for that post — that must be the correct explanation.
I ordered the “early SP35” quite early, so it likely belongs to the first 100 units (with the different reflector) mentioned in that thread.
From visual observation, my eyes couldn’t notice difference with the 2 reflectors though…
Would the buck driver in this be more efficient with a Luxeon V LED as it has a lower Vf?
Marginally. According to djozz’s test it looks like at 6 amps, the Luxeon V has a VF that’s 0.1 volts lower. Probably not enough to make a big difference though. Lumen output looks nearly identical despite the Luxeon V being a 4000K LED. So if you’re going for a CCT change, the Luxeon V could be a good fit. You might have to modify the V’s 4040 MCPCB a little to accommodate the screw sticking up to prevent it rotating. I measured the stock MCPCB at 16.7 mm. Honestly, swapping for a different SST40 would be a much easier option.
I recently tried swapping mine with an 3V XHP50.2 just for fun. Lumens increased a little, but it also got hotter faster. I will say, I expected the tint shift to be worse than it is. On a while wall, I can see it but it’s really not too bad.
Better order N5 DD SST40 from KD. I was lucky to get slightly rosy bin which looks way better than stock 6500K.
The code: WND9F7HE does not work.
The coupon code WND9F7HE is invalid. It has expired.
They might be giving me a new code after CNY. Currently, there’s no one there to ask for a new code.
Odd that the 50.2 made more heat with a regulated driver. Do you have data of high on the SST40? I wonder if it just conducted it faster? Better mcpcb or thermal paste / clamping in your swapped setup? My best guess here is that the lower voltage of the 50.2 allowed the driver to squeeze out a little more current. Above 7A the 40’s Vf isn’t that low.
Also I’m going to buy one as long as it can be confirmed that the ATR free version. A code would be a nice bonus 
Can someone send me a working 15% off code for the Sofirn web site?
Thanks
Update 1: For the moment, there will be no new discount code for SP35. You may save $ 3 upon orders of more than $ 30, that's what I was told.
Update 2: Stock of SP35 without ATR is getting low, so the odds are good to see SP35 with the new improved ATR anytime soon. Sofirn told me maybe in two weeks from now.
Update 3: SP35T (using a secondary, mechanical tailclicky) is in planning now. Sofirn wants to take SST70 into consideration. As this is a 6V LED it would require them to either develop a sophisticated buck-boost driver (if kept as a single-battery flashlight) or to adjust their new buckdriver from SF47T to work in 2S mode (6.0V - 8.4V) with a 6V LED and two batteries in a row. I doubt they plan to release a long-tubed SP35T, though.
I love SP35 size so without tailswitch please or add short tail without it as an option.
And yes, SST70 or xhp50 hi cri would be great.
Oh and the last but not least...tell Barry to include OP reflectors as option. Sick of artifacts and difference in throw is negligable.
I wonder what functionalities and UI they plan to offer with the secondary switch. If it's a mechanical switch (which is 99% certain), it will most likely reduce options to turn off/on and momentary. At least I hope they will bring back the "standby-feature" (soft-off) they had offered in SP70 and C8F, i.e. side switch can power off/on the light while the tailswitch is activated.
XHP50.2 HighCRI? I saw on Simon Mao's thread a 4000K version but I can't remember if it had anything more than 70CRI. Very interesting option, indeed. In the past 3 months Sofirn had difficulties sourcing Cree LEDs, so let's see how things will work out in the future.
If I recall correctly, OP reflectors were a hot topic already with regard to some SP35 reviews posted on BLF. Not sure, if Sofirn is willing to change the reflector once again since they have updated their SMO reflector already. Not sure what they did, possibly a different depth ratio between emitter and reflector aperture. As far as I can see the beam profile looks pretty good, now.
gchart has apparently received one of the improved samples for his review and his beamshots do not indicate many artifacts.
Actually every Sofirn (but SP10S) i have, they all have SMO reflectors and ugly looking beam. And all got dc-fix over lens just to smooth out a bit while killing throw by a lot.
When talking about 90CRI xhp50 i was reffering to DIY swap since SST70 is 6/12V like XHP50 :)