Die porn shot, A5 bin from previous sampling on the left, and the A4 (mass produced) on the right.
Color variation test on two LEDs @4000k: not exactly equal but at least both can be considered in a rosy territory.
As happened in the djozz's samples, the chip on the LEDs indeed aren't perfectly matched. At 9.0v we might see an entire row almost gone missing.
Bumping the voltage slightly to 9.3v and the entire array now lit up fairly evenly. Luckily, at 9.3v my lab bench didn't even register 10ma current-wise. So, the voltage mismatch doesn't seem as serious as it would look at 9.0v. For aesthetics reason, however, you might want to keep the voltage (esp. for ultra-low mode) at 9.3v or above.
Just curious, how do people intend to use this emitter? Which host have you identified that could make use of this emitter? Since it’s 12V, and most XHP 70.2 lights are 6V, doesn’t seem like a lot of opportunities to use this. XHP35 lights are 12V but the optics/reflector will not fit over this.
I’m planning to try the 22mm 2.3A Convoy XHP35 boost driver. I ordered it but have not received it. The mod is probably a Yootoo SD2, because I think it fits the driver reasonably well (stock driver is 23mm). Not sure how the reflector will fit, it needs at least reaming to fit around the led.