When I bought my first Surefire 6P flashlight, I found that the Malkoff M60 (now replaced by the M61) was one of the best P60 LED drop-ins.
I like the beam profile produced by the optic in the Malkoff M60, a hot spot with useful spill. The disadvantage of the Malkoff M60 – for me – is its single mode. I do not need 100% brightness all the time – lower levels of light are sometimes more useful.
One of my favorite flashlight mods is using the DealExtreme 16-Mode 3W 3.7V 7135 Circuit Board for Cree and SSC Emitters (SKU 7612). I like this circuit board because one of the groups has only low-mid-high, with no strobe. I’ve modded my Lumapower D-Mini, an Ultrafire C2 and a few P60 drop-ins with this board.
The modes are in three groups:
1. Low (10%) – Mid (35%) – High (100%) – Strobe – SOS
2. Low (10%) – Mid (35%) – High (100%)
3. Low (10%) – Mid (35%) – High (100%) – Special Police Type Strobe – Slow Strobe (3Hz) – Super Slow Strobe (1Hz) – SOS
I recently bought a Surefire 6P flashlight body that was bored to accept a larger diameter 18650 battery. I thought the DX 7612 would be a good mod for a Malkoff M60. The main problem was getting up the nerve to try to mod the Malkoff M60 because of the possibly destroying a $55 drop-in, but I decided to try it.
The sealing material used around the circuit board and LED in the M60 is called potting. The rear of the drop-in is sealed with this material. I thought it would be a hard material but I found the it was actually soft and rubbery. I used a jeweler’s screwdriver as a chisel to start removing it. As I got close to the circuit board, I used a little lacquer thinner to soften the black sealing material. When I removed all the potting from the top of the board, I used some more lacquer thinner to soften the material in the gaps in the side. After removing the solder, I was able to pry up the circuit board and remove it.
The diameter of the DX 7612 board is about 17mm. The Malkoff had about 16.5mm diameter space for the board, so I used a Dremel sanding band to reduce the diameter of the 7612.
As I disassembled the Malkoff, the robust design was easy to see. When I desoldered the Malkoff circuit board from the housing, I could tell from the way it retained the heat (because of its mass), how well it would work as a heat sink inside the flashlight body.
With the DX 7612 on high and an 18650 battery, the modded Malkoff output looks pretty much the same as the stock Malkoff M60 on high with two RCR123s. I haven’t taken any measurements, but the specs for the 7612 says it puts out 1000ma @ 3.7v, and since I didn’t move the LED or the optic, it seems like my modded Malkoff M60 is just like the stock one but with different levels.