See Maukka's report on 4000k here: https://budgetlightforum.com/comment/1747794#comment-1747794

The 4000k is still in stock, here's final pricing (all transfer fees included)

Item Cost: $12.6 $11.0 (effective december 2020 onwards)

Shipping:  Refer to this thread instead: https://budgetlightforum.com/node/69056

Pay: https://paypal.me/rngwn

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Following the discussion on http://budgetlightforum.com/node/68689

Djozz's test: http://budgetlightforum.com/node/68899 

Meet the GT-FC40, the domeless sister of the XHP series. The one in the picture (on the left) is a 40w LED 5000-5500k (I'd say 5300k) that produces up to 3200lm at 95 CRI.

The one on the right is CREE's XHP70.2 5000k 90 CRI.

Specs (5000-5000k version)

Voltage: 12-14v (13.3v @ 3.0A)

Current: 3.0A (may tolerate above 3.5A, but not recommended) -- Djozz's test indicated that the LED may survive up to 7A (92W) for a few minutes with proper cooling

Output: 3000-3200lm (at nominal current)

CRI: 95+

Construction: Flip-chip blue LED, Silicone-based phosphors

MCPCB: 20mm star

The one above is on A5 bin (5000-5500k), but A4 bin (4000-4500k) is also available.

Anyone who are interested can sign up here, specify the amount and color. You can sign up for both colors, of course.

for example:

• A5 bin 2pcs, A4 bin 3pcs.
• 4000k 2pcs, 5000k 2pcs.

The regular price will be $12/ea, but if a color has the total order of at least 45pcs, OR at least 80 pcs for both color combined, the price for the people in the list will be $11/ea (the discount only applies to the color you signed up with).

I am targeting at least 35pcs/color or 60pcs  total before it's financially viable for me to buy.

The minimum you can buy is 1pcs, but you can contribute to lower pricing for everyone here by pushing the total. There are two methods of shipping: $4.5 Standard (Tracked, 2-4 weeks delivery time), $1.5 Economy (Untracked, 2-8 weeks delivery time *use at your own risk*).

Be responsible, I'm presuming that everyone signing up here are reasonably determined to buy. My motivation to find more stuffs in Alibaba depends on the success of this GB.

Here we are, 4000k has arrived. The 5000k will have to wait.

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.