Q5 emitters. Where do the *picky* guys here get them?

Can they be had as bare emitters and not on a star?

Is there anyone that sells hand picked ones for accurate binning?

Thanks.

http://cutter.com.au/proddetail.php?prod=cut651

I can tell you Mark at cutter have the real goods. I have been to their place myself and saw with my own eyes Q4, Q5, reelssssss in numerous tints, authentic reels of Crees in anti-static packaging. What a sight. They are a little bit higher in price but can be sure of what you pay for.

IMHO, Cree and SSC are very accurate in binning. LED of the same batch are hardly distinguishable in terms of tint. I dare say as accurate than Luxeon, if not more. You should not trust me on this, I am not a high volume buyer.

I bought a few from cutter but I also buy from the online HK stores.

I have bought several Q5's in WG tint from CPF member "endevour" that are really nice.

http://www.cpfmarketplace.com/mp/showthread.php?t=167863

HTH
AlexGT

Got about six WC tint Q5s from Cutter. they shipped pretty fast and they all arrived well packed and working just fine.

katsyonak said:

Got about six WC tint Q5s from Cutter. they shipped pretty fast and they all arrived well packed and working just fine.

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I'm glad you got your order from cutter quicky many other including myself waited over a month to get our orders

Mac

Have you all been checking the Vf? What has it been?
Thanks,
Mike

Thanks guys! I sent Enrique a PM about some. If he doesn't have any I'll buy them from Cutter.

cmacclel said:

I'm glad you got your order from cutter quicky many other including myself waited over a month to get our orders

Mac

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Yes, I heared about it.
I ordered other things as well from cutter (total of 3 orders) and all of them were okay, so either I was just very lucky or who knows...

I've heard "Kai******" in dealer section claims bins that some people doubt very much about.

Has anyone tried and checked? Would you consider this dealer as reliable?

It's so easy to sell P4 WG and claim they are Q5 WC (for either luminous flux and tint, who on this forum can actually bring any proof that it's wrong binning?)

I have bought from both DX Kai and Cutters... The performance has been better on the ones from Cutters everytime.

I've purchased "bare" Q5's from Cutters and been happy each time.
In case location makes a difference to delivery I'm in Australia.
I've also purchased star Q5's from DX and had no problems.
As far as I can tell there is no difference in output between the Cutters and the DX Q5's. (there was an earlier thread discussing this).

vetkaw63 said:

Have you all been checking the Vf? What has it been?
Thanks,
Mike

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Vf with Cree LED's is a CRAPSHOOT. I have never seen LED's vary as much in both tint and VF until these new Xr-e's came around. From the same reel you will have practically every tint available and the VF varies up to a half a volt. Most of the Q5's I have tested are around 3.4-3.5 vf at 700ma and some are 4.0v at 700ma.

As for output. I tested a handful of the Q5's against some Q2's and P4's I had on hand and some of the Q2's where brighter. Needless to say Cree's binning is horrible. At least with Lumileds you knew EXACTLY what you where getting.

Mac

As for output. I tested a handful of the Q5's against some Q2's and P4's I had on hand and some of the Q2's where brighter. Needless to say Cree's binning is horrible. At least with Lumileds you knew EXACTLY what you where getting.

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Oh good, I'm not the only one. I recently got a Q5 from a group buy, and it was just barely brighter than a P4, and noticably underperformed a Q4.

The results were so unexpected it led me to start to doubt my measurement system. I re-tested many different aspects, to verify my previous results. I finally came to the conclusion that the Q5 I got just wansn't a Q5. I've also sent it to another member to verify my measurements.

I feel bad for those who paid a premium for a Q5 only to have it be less efficient and dimmer than the LEDs they already have.

QCG sells them in WC tint. No clue how accurate they are in advertising though.

evan9162 - I do believe that you have a proper setup for testing. Q5 and P4 is way far apart. I have different batches of Q5s they are quite close in terms of light output. I do have a Q5 which is a fluke, after a 2.5A attemp

For others, proper testing of the vf and current requires a semi-permanent testbed. There are certain variables that may or can affect your readings such as die temperature, ambient temp. Some metal oxidize over time, make sure that you use silver plated connectors. If you are using sense resistors/shunt for current reading, it's best to solder the reading points permanently. You will also need something that can read the temperature of the die. It doesn't need to be the accurate real die temperature but note the location the reading was taken. The precision of your equipment is also important. Have you done a 1yr calibration lately? Finally let the CREE, power supply, and multimeter warm up to a stable temperature before tests.

As I said, from my experience the Cree from the same batch are consistent. I have to add that they do differ from batches to batches. I know I have a reliable source, the cree Q5s I have was removed from sealed reel. I marked them, I use them as a 'benchmark' control to test other Crees.

If you have a Cree Q5 that outperforms the others, you can make it your 'real' Q5. If new Q5s performance that you have is not even close to your real Q5, then there is something to suspect. Could be a problem with your source.

I have purchased hundreds of Cree's directly from a Cree Authorized dealer and found the VF and tint from the same reel differs greatly. I have not tested brightness of the previous LED's I purchased but may start.

Mac

Mac, I believe Cree does not bin their LEDs for vf so they can be high and low. How far apart is the tint. How do you measure them? Do you use a reflector to collect the light? Very interested to know from a high volume user point of view.

koala said:

Mac, I believe Cree does not bin their LEDs for vf so they can be high and low. How far apart is the tint. How do you measure them? Do you use a reflector to collect the light? Very interested to know from a high volume user point of view.

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The tint variation between emitters from the same reel I have had has been huge. From white to yellow to purple. It is so bad I prescreen all my LED's before installing them into muliple LED lights.

Mac

On a tri or quad Cree mod, it is very easy to mask all LEDs except one, and then rotate your mask to compare tints.

I've just tried on a quad P4-WC and YES the tint is very different from an emitter to another. All four Leds were taken out of the same reel :huh:

Two are pretty snow white, one is more yellow and one is more blue. Doesn't really matter, since they are working together... and the "average" when using all four normally is a perfect and nice white tint so I guess I can't complain.

But thanks for pointing this out, I have totally discovered this today. That said, by doind what I just said you switch from an emitter to another very quickly, which makes any difference in tint look dramatic. If I had to test these leds separately, I can't garantee I would have seen a clear difference.

cmacclel said:

The tint variation between emitters from the same reel I have had has been huge. From white to yellow to purple. It is so bad I prescreen all my LED's before installing them into muliple LED lights.

Mac

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+1.
I have two emitters from the same reel, neighbors actually, one is a perfect WC tint and the other one is a yellow green WH? at the same V & A levels. Same goes for vf, one can be be 3.54 V at 1 A and the next one is 3.99 V at 0.7 A.
Stefan