As I mentioned in the [last post](https://old.reddit.com/r/flashlight/comments/1f4cr2n/nmd_zebralight_sc65c_hi_1_maximum_performance/), I’ve been doing a lot of tinkering with the SC65c HI since it was released last year. Most of that has been focused on using Cree XHP35 instead of the original Nichia 719A, for both the higher output and moderately throwy beam that made the discontinued SC64w HI so popular.
Zebralight drivers are quite flexible about output voltage, and simply reflowing an XHP35 will technically work. However, the output *current* remains fixed at 1.5A, which results in a very fast 30 second stepdown with the higher voltage XHP35, and other major driver components are poorly matched to this configuration. /u/m4potofu quickly discovered the original driver design was [missing critical components](https://budgetlightforum.com/t/efficiency-measurements-of-a-few-drivers/68528/92) that heavily impacted the efficiency even with the stock light, making this higher power mod even worse. Luckily he came up with an easy fix, and it hasn’t been an issue on new drivers since last October. I am also indebted to him for his helpful advice, as well as patiently listening to me complain about various issues I encountered 😅
As it turns out, the SC64w HI has a pretty appropriate maximum output for its body size, and with some careful measurements and well-chosen component values, it’s possible to essentially recreate it using the SC65c HI, with the added benefit of a slightly more efficient driver. This is by far the most complex Zebralight mod I’ve done: all told, I replace or add a dozen components, including the addition of a small circuit to fix a significant bug that impacts normal operation with XHP35. This is the general configuration I’ve been using for most modded SC65s I’ve shipped this year, and I thought it was probably time to make a post about it.
To give a good demonstration of the mod, I made this SC64w HI clone using a CRI 80 XHP35.2 HI. I also chose the SC64w HI with the nicest tint from my collection. As you can see, these lights are very closely matched, to the point they are functionally identical. The one difference I’ve consistently noted is that the SC65 has more conservative PID tuning, probably due to the lower original output. Bumping the temperature calibration a couple degrees higher resolves this to my satisfaction and gives extremely similar runtime performance to the SC64w HI.
1 Comment
As I mentioned in the [last post](https://old.reddit.com/r/flashlight/comments/1f4cr2n/nmd_zebralight_sc65c_hi_1_maximum_performance/), I’ve been doing a lot of tinkering with the SC65c HI since it was released last year. Most of that has been focused on using Cree XHP35 instead of the original Nichia 719A, for both the higher output and moderately throwy beam that made the discontinued SC64w HI so popular.
Zebralight drivers are quite flexible about output voltage, and simply reflowing an XHP35 will technically work. However, the output *current* remains fixed at 1.5A, which results in a very fast 30 second stepdown with the higher voltage XHP35, and other major driver components are poorly matched to this configuration. /u/m4potofu quickly discovered the original driver design was [missing critical components](https://budgetlightforum.com/t/efficiency-measurements-of-a-few-drivers/68528/92) that heavily impacted the efficiency even with the stock light, making this higher power mod even worse. Luckily he came up with an easy fix, and it hasn’t been an issue on new drivers since last October. I am also indebted to him for his helpful advice, as well as patiently listening to me complain about various issues I encountered 😅
As it turns out, the SC64w HI has a pretty appropriate maximum output for its body size, and with some careful measurements and well-chosen component values, it’s possible to essentially recreate it using the SC65c HI, with the added benefit of a slightly more efficient driver. This is by far the most complex Zebralight mod I’ve done: all told, I replace or add a dozen components, including the addition of a small circuit to fix a significant bug that impacts normal operation with XHP35. This is the general configuration I’ve been using for most modded SC65s I’ve shipped this year, and I thought it was probably time to make a post about it.
To give a good demonstration of the mod, I made this SC64w HI clone using a CRI 80 XHP35.2 HI. I also chose the SC64w HI with the nicest tint from my collection. As you can see, these lights are very closely matched, to the point they are functionally identical. The one difference I’ve consistently noted is that the SC65 has more conservative PID tuning, probably due to the lower original output. Bumping the temperature calibration a couple degrees higher resolves this to my satisfaction and gives extremely similar runtime performance to the SC64w HI.
#Output
Level | SC64w HI (spec) | SC64w HI (measured) | SC65c HI CRI 80 XHP35.2
— | — | — | — | — | —
H1 | 1300 | 1149 | 1093
H2 | 814 | 703 | 707
H3 | 467 | 397 | 404
H4 | 245 | 212 | 212
M1 | 118 | 101 | 90
M2 | 52.5 | 45 | 38
M3 | 21.3 | 19.0 | 20.4
M4 | 7.9 | 7.1 | 8.1
L1 | 2.7 | 1.8 | 2.6
L2 | 0.86 | 0.80 | 0.62
L3 | 0.24 | 0.25 | 0.19
L4 | 0.06 | 0.08 | 0.06
#Colour
**SC64w HI**
Level | CCT | Duv | CRI (Ra) | CRI (R9) | Rf | Rg
—|—|—|—|—|—|—
H1 | 4569K | -0.0008| 81 | 9 | 79 | 98
M1 | 4157K | 0.0012| 83 | 16 | 82 | 96
L1 | 4089K | 0.0008| 84 | 21 | 82 | 96
**SC65c HI CRI 80 XHP35.2**
Level | CCT | Duv | CRI (Ra) | CRI (R9) | Rf | Rg
—|—|—|—|—|—|—
H1 | 4715K | -0.0009| 81 | 10 | 78 | 100
M1 | 4359K | 0.0009| 83 | 18 | 82 | 98
L1 | 4306K | 0.0013| 84 | 19 | 82 | 98