Modified Malkoff Devices M60 Drop-in

Modified Malkoff Devices M60 with 8xAMC7135 (2.8A) multi-mode driver
Modified Malkoff Devices M60 with 8xAMC7135 (2.8A) multi-mode driver

Malkoff Devices designs and manufactures high powered LED flashlight modifications for Maglites and Surefire flashlights and their own Malkoff LED flashlights. Their products are so well designed and constructed that they are coveted by professionals that depend on their flashlights and enthusiasts that appreciate their quality.

I bought my first Malkoff Devices M60 drop-in five years ago. The M60 drop-in had a Cree X-RE LED (Q5 bin) and Khatod 6 degree optic. This drop-in output 180 lumens driven at 1000 mA with a 2-3 hour runtime with two CR123 batteries. I wanted to update my M60 with a more powerful driver/LED combination.

In 2008, Cree XR-E LEDs were delivering 220 lumens at 1000 mA. In December of 2012, Cree introduced the XM-L2. Driving the XM-L2 U2 bin at 1000 mA will produce about 412 lumens. At 3000 mA, the XM-L2 will produce over 1000 lumens.

Multi-mode flashlights are more useful for me so I decided to use an 8xAMC7135 (2.8A) multi-mode driver and a Cree XM-L2 (U2 bin). The multi-mode driver has four configuration options, selectable during the build by grounding one of the four “stars” on the rear of the circuit board:

  • Star 1: 5/30/100/strobe/SOS
  • Star 2: 5/100/strobe
  • Star 3: 5/30/100
  • Star 4: 5/100
Modified Malkoff Devices M60 with McGizmo McR20J reflector
Modified Malkoff Devices M60 with McGizmo McR20J reflector

Because of the robust nature of the Malkoff drop-in, disassembly is basically destructive. The stock circuit board is potted and the LED MCPCB is securely glued.

To get the 8xAMC7135 driver board to fit in the Malkoff brass heatsink, I had to slightly reduce the 17mm diameter of the circuit board.

To solder the LED to the MCPCB, I used a lead solder paste with a SMD hot air rework solder station at 220 degrees C for 40 seconds. After applying some Artic Silver 5 CPU Thermal Compound to the bottom of MCPCB, I glued it to the heatsink with JB Weld.

After some research on reflectors, I chose the McGizmo McR20J (Joker). A glow-in-the-dark o-ring holds the reflector very securely in the heatsink.

I compared this mod to the EDCPlus/IS X60L3 Triple XP-G2 LED P60 Dropin. The Malkoff mod has a very nice hotspot while the EDCPlus Triple has a broad floody beam. I like the nice hotspot the Cree XM-L2 produces with the McGizmo McR20 Joker reflector. It also has a decent amount of spill.

Modified Malkoff Devices M60 with McGizmo McR20J reflector beam shot
Modified Malkoff Devices M60 with McGizmo McR20J reflector beam shot

For this beam shot, I converted the original color image to black and white. The drop-in was about four feet (1.21 m) from the wall. On this off-white wall, there is a slight, but noticeable green tint from the beam.

I put the drop-in in my Surefire C2. Instead of wrapping the drop-in with copper tape, I used some thin aluminum stock as a shim. I haven’t done any runtime tests but after 10 minutes on 100% power, the C2 bezel gets warm but not hot.

Parts sources:
Malkoff Devices Drop-ins for Surefire and Malkoff
Cree XM-L2 LED
8xAMC7135 driver board at Shiningbeam.com (2.8A) and Illumination Supply (3.04A)
McGizmo McR20J (Joker) Reflector

Malkoff M61 Modded Some More

After I put in a 3 mode 1.4 A driver in my Malkoff Devices M61 drop-in, I wasn’t too happy with the yellow/green tint of the Cree XP-G LED. I found a cooler tint XP-G and applied some Arctic Silver 5 Thermal Compound to the back of the LED board and used some Arctic Alumina Thermal Adhesive to hold the assembly in place.

Malkoff M61 with cooler tint Cree XP-G LED

Before I reassembled the drop-in, I wiped some hazing off the reflector with some chrome polish and inadvertently removed some of the reflective finish. I needed a new reflector.

Modded Malkoff M61 and McR-20 Seoul reflector

I searched for reflectors for the Cree XP-G and found positive comments about Don McLeish’s McR-20 Seoul reflector. I ordered one from the Sandwich Shoppe and it was delivered in 2 days.

There is a recess around the top of the M61 heat sink that the top of the stock reflector sits in – that’s the flat part of the reflector. I put a GITD (Glow In The Dark) O-ring in the recess and it held the McR-20S reflector perfectly. The new LED is mounted on a thinner circuit board than the Malkoff board, which in this case helps with the reflector placement. The bottom of the reflector (with a thin insulator) rests on the LED board. The other end of the reflector is flush with the end of the heat sink.

The beam is very nice. Compared to a M60 or M30, there is less of a hot spot and more spill. The stock M61, IIRC, didn’t have as much of a hot spot compared to the McR-20S.

So far in this mod, I have destroyed the Malkoff M61 driver board and damaged the reflector. But now I’m happy with a drop-in that has a great heat sink, a great beam and three modes. It’s now in my current favorite flashlight, the Surefire C2.

Modded Malkoff M61 in Surefire C2