[Modding] Astrolux MF01 --> OSH park NarsilM


I’m a big fan of the narsilM UI and i asked LEXEL to get a driver for me.
I changed the LED wires from 24AWG to 22 AWG (i think 20awg is really hard to fit)
I changed the driver for a OSH park NArsilM
Next thing to do is bypassing the spring from the battery pack

My ceiling bounce test for 219C version of the original MF01 give me 450 Lux
My ceiling bounce test with modded driver give me 600 Lux.

I gain output and the ramping function !
So great mod i recommand you the same.
The only drawback is that you loose led switch for battery level…but i don’t really care because driver is equipped with LVP.

Nice i got one being built by lexel now.Did you hook switch light back up?


no i did not connect the side led to the Br pad of the driver.

Can somebody make a video on how to do this lol. I also have MF01 coming my way and I want to mod it to produce more lights and better UI too


that’s easy ! You need to solder the 2 wires from the side switch :white and black
The green and red are left unused.
Then you solder the grey wires from the LEDS (positive) and blacks (negative)

Nothing more to do !

As a super noob with flashlights and tools…. I’ve never used solder before.
Could be the picture look like it has a lot going on…

Can you please make some pictures in some more details? (ex. w wires from side switch: what should they look like after solder together)
Sorry for asking if the question is kinda dumb… :cry:

Comparaison with MT07S / MF01 / L6

stock MT07S on turbo :

Video coming (uploading…)

Yea I’m sold… that MF01 Nichia after mod is crazy!!
So you got new wires yourself not from Lexel. Correct?

Question, anyone know if this harms the LED or shorten it’s life? Or as long as we keep it cool and don’t boost it back on after step-downs we should be good?

So I have an MF01 and was considering this. Is the brass driver ring that the battery tube contacts soldered to the stock driver? If so how did you remove it?

What settings did you choose for your driver?

the current is divided through 9 emitters 2 in series
so about 2.5A per LED

you have per emitter a relative low current compared to single LED builds

even if most people does not believe it if the LED stays cool a higher current it ages less than on normal current
and on low modes it ages a lot faster than on normal current
so moonlight is a real lifetime killer for LEDs

This is also why you often find minimum current requirements in datasheets to get to the right lifetime

LEDs age a lot faster on low currents? Any link/reference that supports this funny statement?

It is physics, the current protects the active zone from degradation

Watch this video

The picture before it plays shows the aging with current, the solid line shows longer life for 350mA, while the other for 100mA shows less for the same LED temperature, a DTP star keeps the LED a lot cooler than conventional cheap aluminum stars that are used in most application to save costs

There are tests that clearly show that if the LED keeps cool enough on the LED die a higher current makes in fact the LED age less than on lower current
LED ages from a process that is mainly rapidly increased at low currents like moonlight or low the LED can age 10 times faster than on full current

I watched this video multiple times

And I am native german, so I did understand well why low currents are far worse than heat to kill LEDs

The current protects the very thin active light emitting zone from electrically defective spots to migrate into it from the surrounding material, this active zone is a lot thinner than the rest so migration is a huge issue
Of course heat also increases the migration of electrically defective spots

On our CC moonlight flashlight the LED can age over 10 times faster than on max. rated current
You see the plot at 16:00 of the video
And that plot shows the LED running on 3% of its normal current
Our moonlights and firefliey modes on CC lights get below 0.1%

The odd thing is if we get good cooling an overdriven LED ages slower than at rated current when they got the same junction temperature

Ok, so what about PWM modes? if we have 1A with 0,1% duty cycle, will it cause LED to degrade 10 times faster as well?…

Pwm modes at LED nominal currents will be fine for lifetime
For XPL this means 0.35-3A on a cheap star if the junction stays within specification temperature limit

Basically the cooler it runs and the more current it gets the less it ages


thanks lexel for the details. interesting indeed ! i wouldnt imagine that behavoir for low current. physics are not always obvious

Thanks for the video, I'll check it later, but I can say immediately something is wrong in "less current - less lifetime" logic,

if this is correct then worst case for LED lifetime is not to turn LED at all (leave it in reel for 1 year).

If 10x lifetime decrease at very low currents (0mA must be the worst by this logic) is true, then completely new,never used LED 1 year after production would be at the end of its life (1 year is ~8000hrs, 10x is ~80000hrs).

Your claim that "more current - less ageing" is completely wrong, you can check some L70 tests for various LEDs, at same Tj, LED at higher current ages faster.

This picture summarizes temperature and current effect on LED lifetime(btw check LED lumen output at 350mA - no drop at all after 100000 hrs):

In the Osram video they talk about a 350mA LED
At 100mA and 150dC it ages slower than on 10mA with 55dC, if you compare both pictures

So why do have Luxeon LEDs the opposite lifetime correlation?

Likely because at some point another factor comes in play.
Maybe thermal stress, who knows

In any case if you cool the LED better the lifetime gets rapidly better as well.

At very low currents the LED gets damaged by diffusion of defective spots in the active zone.

At zero current or close there is not enough energy present to move defective spots.

Even if he drives a XHP70 at 6V 7.2A with a DTP star he gets thousands hours to 70% brightness
If he drives a XHP70 at 50mA it will age probably as fast as with 7.2A

In flashlight use noone will probably see a significant degradation of brightness with a lot normal use

Nice! I’ve been on the fence about this mod ever since I noticed that one bank of leds is a tiny bit dimmer than the other two when in low mode.

It looks quite do-able and I love ramping on my other lights (Q8 and D4).

Any challenges or bumps in the road to look out for? How was it taking off the bezel to get at the emitters? Wasn’t there a warning from Astrolux about removing the bezel and damaging the leds?

So in other words making a moonlight with very low duty cycle PWM should increase LED life while the same moonlight with constant current will make it wear much more rapidly (altough with little more lumens per watt)…
I wonder if 20+ kHz range PWM can have any negative effect on LED though…