Thrunite Neutron Series (XM-L) 1C, 2C, 1A, 2A Review: RUNTIMES, BEAMSHOTS and more!

Warning: This round-up review of the Neutron family is a LOT more pic heavy than usual. :sweat:

Following in the style of my other series round-up reviews threads, this review will look at all members of the Thrunite Neutron family of lights - 1C (1xR/CR123A), 2C (2xR/CR123A), 1A (1xAA), and 2A (2xAA).

For the sake of clarity, I will only use representative body pics (mainly from the 2C) for the general overview discussion below. More specific pics (including beamshots) will be included with the individual light runtime graphs and summary tables.




Common Manufacturer Specifications:

• LED Emitter: Premium Cree XM-L T6
• OP reflector
• Stainless steel bezel
• 5 current-regulated output levels (Reviewer's note: the Neutrons are actually PWM-regulated)
• 2 flash modes: Strobe, SOS
• Reverse-click switch
• Square threads for a lifetime of smooth operation
• Type-III Hard Anodized finish
• Sapphire coated lens
• IPX-8 Waterproofing
• T-6061 Aircraft-grade aluminum body
• Capable of standing up securely on a flat surface to use in "candle mode"
• Two modes (7 types) of output selected by turning the bezel:

Neutron 1C Specs:

• Dimensions: Length: 3.5 in (88.9 mm), Diameter: 0.87 in (22.1 mm), Weight: 1.69 oz (45 g) (without battery)
• General Mode: 0.09lumens (100hrs) 9 lumens (33hrs) -> 50 lumens (6hrs) -> 120lumens (2.1hrs) -> SOS
• Turbo Mode: 255 Lumens -> Strobe
• MSRP ~$60

Neutron 2C Specs:

• Dimensions: Length: 4.9 in (124.46 mm), Diameter: 0.87 in (22.1 mm), Weight: 2.65 oz (75 g) (without battery)
• General Mode: 0.1 lumens (325hrs) -> 9 lumens (65hrs) -> 65 lumens (9hrs) -> 120lumens (4hrs) -> SOS
• Turbo Mode: 330 lumens (1.5hrs) -> Strobe
• MSRP ~$70

Neutron 1A Specs:

• Dimensions: Length: 4.1 in (104.14 mm), Diameter: 0.87 in (22.1 mm), Weight: 2.12 oz (60g) (without battery)
• General Mode: 0.09lumens (100hrs) 9 lumens (34hrs) -> 50 lumens (6hrs) -> 105 lumens (2.2hrs) -> SOS
• Turbo Mode: 145 Lumens -> Strobe
• MSRP ~$60

Neutron 2A Specs:

• Dimensions: Length: 6 in (152.4 mm), Diameter: 0.87 in (22.1 mm), Weight: 2.65 oz (75g) (without battery)
• General Mode: 0.1lumens-> (260hrs) 9 lumens (33hrs) -> 50 lumens (6hrs) -> 120 lumens (2.1hrs) -> SOS
• Turbo Mode: 255 Lumens -> Strobe
• MSRP ~$65

Packaging is fairly typical for these sorts of lights (i.e. simple cardboard box with molded plastic insert). Inside you will find the light, manual, wrist lanyard, spare o-rings and elastic belt holster.

All dimensions given with no batteries installed:

Neutron 1C: Weight: 45.2g, Length: 91.5mm, Width (bezel/tail) 22.0mm
Neutron 2C: Weight: 57.6g, Length: 123.8mm, Width (bezel/tail) 22.0mm
Neutron 1A: Weight: 60.4g, Length: 156mm, Width (bezel/tail) 22.0mm
Neutron 2A: Weight: 76.4g, Length: 250mm, Width (bezel/tail) 22.0mm

Scroll down to the individual light reviews for comparison pics to other lights.







The Neutron series build is pretty much what you would expect for this sort of family of lights. The components are generally interchangeable among the family (i.e. common threading and diameters for the heads/tails).

On the whole, they look the most like the 4Sevens Quark lights, but there are some similarities to the Fenix and Olight lights as well. The most distinctive aspect is probably the consistency along their lengths - the Neutrons are among the most cylindrical (i.e. cigar-shaped) of all the lights I've tested (e.g. bezel and tail diameters are identical, and the body tube is only slightly thinner).

Black anodizing (type III = HA) is matte-finish, and lettering is bright white and clear on the black background. Knurling is generous and reasonably aggressive (more aggressive than most). :thumbsup:

Tail threads are anodized at body the battery tube and tailcap regions, allowing for lock-out. The lights can tailstand, but there was a bit a wobble on one of my samples. Note the switches are all reverse-clickies.

All lights except the 1C come with a removable forward-facing pocket clip (with a ring cover over the attachment point). Note the clip is not reversible. And although the heads and tails could be reversed on the body tube (i.e. common threading), the anodized tailcap threads would prevent you from using most of the modes if you tried this.


There's nothing wrong with the emitter above - that's just a shadow from the camera angle.



The Neutron family comes with the latest high-output Cree emitter, the XM-L. Reflector is common to all models, and is fairly deep and MOP-textured. Emitters were all well centered on my samples.

Due to the larger size die of the emitter, I would expect these lights to be somewhat floody - but with a narrower spillbeam width due to the deep reflectors. Scroll down to my individual reviews for beamshot comparisons to other lights of their respective classes.

User Interface

The UI will feel familiar to users of the regular 4Sevens Quark or Fenix LDx0/PDx0 series lights.

Turn on/off by fully pressing the reverse clicky switch (i.e. click needed to turn on).

With the head slightly loosened, you get one of five possible modes. Soft-press the switch to advance through Firefly, Lo, Med, Hi, and SOS, in repeating sequence. The light has mode memory, and retains the last setting used when you come back into the head loosened state.

With the bezel fully tightened, you get Turbo. Soft-press to advance to rapid Strobe (soft-press again or turn off to get back to Turbo). There is no memory for the head-tightened mode – you always get Turbo on activation with the head tightened.

PWM/Strobe

Despite the claimed current-control in the specifications for this family, I found all lights used pulse width modulation (PWM) on the Lo/Med/Hi output modes.

The frequency on the 1C, 1A, and 2A lights was consistently high, measured at 4 kHz at all levels. This is sufficiently high that you won't see it in practice.



The 2C was a different matter, however. PWM was a very noticeable 110 Hz at Lo-Med-Hi levels. I found this to be very distracting, especially on the Lo mode. :shakehead



Strobe was consistently in the low 13 Hz range on my samples (i.e. 13.0 – 13.4 Hz).




Testing Method:

Effective November 2010, I have revised my summary tables to match with the current ANSI FL-1 standard for flashlight testing. Please see http://www.sliderule.ca/FL1.htm for a description of the terms used in these tables.

All my runtime graph output numbers are relative for my home-made light box setup, a la Quickbeam's flashlightreviews.com method. You can directly compare all my relative output values from different reviews - i.e. an output value of "10" in one graph is the same as "10" in another. All runtimes are done under a cooling fan, except for any extended run Lo/Min modes (i.e. >12 hours) which are done without cooling.

I have recently devised a method for converting my lightbox relative output values (ROV) to estimated Lumens. See my How to convert Selfbuilt's Lighbox values to Lumens thread for more info.

-------------------

Individual Light Runtime/Output Comparisons

Neutron 1C



From left to right: Surefire CR123A; Thrunite Neutron 1A; Foursevens Quark Q123; Liteflux LF3XT; Sunwayman M10R; Novatac 120P; Zebralight SC30; ITP SC1.

All lights are on Hi on RCR (AW Protected where available), about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.




















-------------------

Neutron 2C




All lights are on Hi on 18650 (AW Protected where available), about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.













UPDATE March 23, 2011: Summary tables and runtimes for the 2C have just been added below. Note that the 2C cannot take protected 18650 or 17670, so I had to use the much lower capacity 14670 for the runtimes.

















A note about the runtimes above - for some reason, the output levels of the 2C on Lo/Med/Hi are a fair amount lower than the 1A, 2AA or 1C versions. See my new Summary table at the end of the review for a comparison. There also seems to be a drop in efficiency on the 2C on the lower outputs, at least for the Med and Hi mode tested.

-------------------

Neutron 1A





All lights are on Hi on Sanyo Eneloop, about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.




























-------------------

Neutron 2A




All lights are on Hi on 2x Eneloop NiMH, about ~0.75 meter from a white wall (with the camera ~1.25 meters back from the wall). Automatic white balance on the camera, to minimize tint differences.























-------------------

Summary of Output Levels

UPDATE March 23, 2011: I have now completed all runtime testing (shown above). For your reference, here is a table showing the relative INITIAL output levels, in estimated Lumens from my lightbox, for all models on various batteries.



A few observations:

• Thrunite's official ANSI Lumen numbers seem reasonably good overall (see specs at the top of the review) - in fact, they seem a bit conservative on most models. Note again the table above is initial lumen estimates in my lightbox, not ANSI FL-1. For max and min ANSI FL-1 estimates, see the individual summary tables scattered throughout this review.
• The 2C is lower in output on Lo/Med/Hi than the other lights of the series
• The 1C/1A/2A head definitely seems to be common to all 3 models, given how they perform on various battery sources

---------------------

Potential Issues

The Neutrons use PWM for Lo-Med-Hi levels, not current-control as listed in the specs. PWM is high enough to be undetectable by eye on the 1C, 1A, and 2AA (i.e. 4kHz). However, PWM is a very noticeable 110 Hz on the 2C.

Output levels on Lo/Med/Hi is lower on the 2C compared to the other lights of the series, and there is a clear relative drop in efficiency at these levels (i.e. the 2C performs at below the level of a typical XP-E R2 light on Med/Hi).

My 2AA sample was defective on its Firefly mode (i.e. no light produced). All other samples performed as expected.

Switches are reverse clickies, and a feel a bit "squishy" to me.

Clips are not reversible, and the clip on the 1AA scratches the head slightly as you turn it.

Preliminary Observations

Ok, there's a lot to summarize up there. :sweat:

Build-wise, the Neutrons impress as solid, well-made lights. Styling is a matter of personal preference, and the Neutrons are fairly streamlined. They are also very functional, with generous knurling and removable clips (except for the 1C which has no clip). Note the clips/bodies are not reversible, as the tailcap threads are fully anodized for tailcap lock-out.

The first thing you probably want to know is the output – does the XM-L emitter make a difference over all the XP-G based lights? On higher voltage battery setups, the answer is clear – absolutely. I'm actually surprised at how much brighter the lights are on 3.7V Li-ion or 2xAA - in some cases, nearly twice as bright as their XP-G counterparts.

A point to keep in mind here is the relative beam pattern. With the larger die of the XM-L, combined with a small head (with small reflector), this will produce a more floody beam (i.e. less focused for throw). But the Neutrons are not really pure flood lights, as the deeper reflectors produce a narrower spillbeam. See the beamshots above for relative comparisons. Since we largely perceive brightness by how bright the hotspot is, the Neutrons may not look as bright as they actually are. But handle these lights in an enclosed space, and you will quickly see how much higher the max output is on most batteries. oo:

On 3.7V Li-ion sources, output/runtime efficiency is quite good at all levels, across the whole Neutron family. Runtimes on Max are very good considering the actual output levels, and the Neutrons' Med/Hi modes handily outperform the comparable output levels of the XP-G R5 lights, in every class. :thumbsup:

On lower voltage battery sources, efficiency of the Neutrons is still good but less impressive - typically closer to the XP-G lights, especially by Med output. I suspect the reason for this is the difficulty in boosting these battery sources to the level needed to run the XM-L emitters. The high frequency PWM may also contribute here.

UPDATE March 24, 2011: The 2C seems to have a relative drop in efficiency on the Lo/Med/Hi modes, compared to the other lights. See updated runtimes above.

On that note, I am personally quite willing to sacrifice a little efficiency for undetectable PWM, and thus appreciate the 4kHz PWM on the 1C, 1A, and 2AA. The 110Hz PWM on the 2C is very noticeable however, so I urge you to carefully consider before purchasing this model (i.e. if you are sensitive to PWM, you will find the 2C very distracting). In comparison to PWM, current-controlled would be better for max efficiency, but it also tends to produce some tint shifting at lower drive levels. On the subject of tint, all four of my Neutron samples were premium white – no sign of the "green meanies" of some XM-L lights. Of course, YMMV …

I like the wide range of levels, and their relative spacing. The interface will feel very familiar to users of the regular 4Sevens Quarks and Fenix LDx0, PDx0 series.

If you are in the market for a relatively floody light in the classic minimalist body shape – with extreme max output and good runtimes at all levels - the Neutrons may be the series for you. Given the output capabilities of the XM-L emitter, I have no doubt other makers will begin introducing them into their lines, so it will be interesting to see how they compare to these early offerings. But the Neutrons are definitely a solid opening salvo.

----

Neutrons provided by Thrunite for review.

Thanks for the great review! I was thinking about purchasing the 2C, but thanks to your input I will delay until I hear the PWM issue has been fixed!

Excellent review there as always Selfbuilt. I hadn't considered the narrower spill when I spoke of the floodiness of their beams. Honestly, I didn't realize that these were PWM. That's definitely saying something too since I am particularly sensitive to it normally.

awesome review, thanks for the write up

SoCal5150 said:

Thanks for the great review! I was thinking about purchasing the 2C, but thanks to your input I will delay until I hear the PWM issue has been fixed!

Click to expand...

Just heard back from Thrunite, and the 2C will remain at 110Hz. I will now proceed with runtime testing of the sample I have, and update the review when it's done.

Personally, I recommend people carefully consider this when deciding on the 2C model. If you don't notice PWM, you shouldn't find it an issue. But if you are sensitive to it (and I certainly am), the 110Hz will be quite noticeable. For some reason, I find it intolerable on the Lo mode (while just distracting on the Med-Hi). :shrug:

AardvarkSagus said:

Excellent review there as always Selfbuilt. I hadn't considered the narrower spill when I spoke of the floodiness of their beams. Honestly, I didn't realize that these were PWM. That's definitely saying something too since I am particularly sensitive to it normally.

Click to expand...

Yes, it's very hard to detect 4Hz PWM visually (i.e. 1C, 1AA, or 2AA). You would have to shine the light at a very fast moving fan, and look carefully for the subtle signs of it. In actual practice, I would consider it virtually impossible to notice. The 110Hz 2C is a different matter. I find the 2C Lo mode particularly :green:.

As for the "floody" aspect, the narrower spill actually helps concentrate the light more evenly, so the actual spill area illuminated seems brighter than on a light with a shallow reflector (e.g. 4Seven Mini). Still, I suspect a lot of people expect both a wide-spillbeam and reduced-throw for "floody" lights, so I like to clarify the difference when it exists. I do consider it very floody personally.

That's too bad about the 2c. I wanted to purchase one as my main work light but saw the complaints about PWM so I stayed away. Now that you've confirmed that's its deliberate and not an isolated issue ill have to pass on these awesome looking lights.

Neutron fun

What is the maximum input voltage? Can the 2A handle two 14500? (or 14670 + spacer)
Does a 17670 fit the 2C??

I think that the 1A will be the most popular. Alkalines (firefly, low, medium) EA91 (firefly, low, medium, high) L91 (firefly, low, medium, high, turbo), 14505 [3 volt primary], 14500's

Re: Neutron fun

MichaelW said:

What is the maximum input voltage? Can the 2A handle two 14500? (or 14670 + spacer)
Does a 17670 fit the 2C??

Click to expand...

You would have to confirm with Thrunite, but I seriously doubt the 2A can handle 2x14500. You would like need to use the low-PWM 2C head on the 2AA body for that. FYI, this likely explains the difference between the 1A/2AA/1C and 2C PWM - the first three likely share the same head, and the 2C has a different circuit for the higher voltage (which for some reason needs lower PWM).

Certainly a single 3.7V Li-ion should work fine in the 2A.

For the 2C, my AW protected 17670 don't fit. Aw protected 14670 does, though.

Re: Neutron fun

I re-read Neutron announcement, 4.2 volts tops, but that doesn't specify if it applies to all. How many people would use 2x rcr123 in lieu of 17670? Maybe Thrunite will commonize the 2C head with the rest of the family?
How hot did they get with Li-ion?
Because I'd like to see what 3x AA Eneloops in series can do, just not 3x AA long. {Imagine a snake digesting a pig; reverse hour glass; a short rolling pin}

I take it your move went well.

Re: Neutron fun

WOW! The XML is really impressive! Combined with the right light (contant current, slightly larger head) it could be freaking amazing!

Re: Neutron fun

Another outstanding review. How do you find the time?

Brightnorm

Re: Neutron fun

Excellent review selfbuilt!

I've got the 1C version and think it's a great little EDC light...solid build, great floody beam, nice tint...probably the brightest 1x123 form factor light I currently own. And as expected, you nailed the only criticism I have for the Neutron series...the dreaded "Squishy" clicky. It is by far the squishiest clicky/rubber boot cover combo I've ever felt. It's pretty obvious and sometimes I find that the rubber boot cover actually squishes so much that my thumb pushes the rubber boot cover to one side and fails to activate the actual clicky. The Neutron is a solid light and I'm happy to carry it, but I'm just not sure why Thrunite would put out such a "squishy" clicky...

As a long time lurker here I've been awaiting your review regarding the Neutron 2C. I've previously purchased the 2A and just loved the light, so much so that I was considering the 2C version but read negative comments regarding the PWM issue. Now that you have confirmed the annoying PWM (your reviews have been a deciding factor in many of my torches), the 2C will be a pass....

It's too bad to as the Neutron series is a great light, at least in the 2A version which I have. The cylindrical body, you mentioned, is very nice in its consistent diameter throughout. No weird cutouts or shifting diameters, just a nice moderately knurled tube. The knurling is a little more aggressive than some of the other lights in its class, (i.e. 4Sevens, Fenix) and provides a very good grip.

You nailed everything else I observed regarding this series of lights, no need for me to expand but thanks for another helpful review!lovecpf

Nice! When do the neutrals and warms start coming out?!?!

Lost my old QAA, need a replacement but want a different tint.

Excellent review and thanks for hard work.

I think the runtime graph of 2A shows the almost flat curve and regulation is maintained nicely untill batteries run dry among Neutron series.

By the way, Can your 1A tailstand stably? My 1A can't, but 2A can do that stably. :shrug:

Thanks for the support everyone. :grouphug:

MichaelW said:

Maybe Thrunite will commonize the 2C head with the rest of the family? How hot did they get with Li-ion?

Click to expand...

No, they wouldn't do that - there's an efficiency hit by supporting wider voltage ranges. Every series I've ever tested always used a different circuit for the 2xCR123A model (e.g. 4Sevens, Fenix, Olight, etc.), and a common one for 1xAA, 2AA and 1xCR123A.

As for heat, I didn't notice anything too unusual during handling - they warm up, but not uncomfortably so in the hand. Runtimes are all done under a cooling fan, though. I would personally limit the time I ran any of these on Turbo, to be on the safe side (and ensure hand-cooling or a fan on them, not just tailstanding).

brightnorm said:

Another outstanding review. How do you find the time

Click to expand...

I ask myself the same question. :sweat: This review took awhile, given all the runtimes and data analysis needed (basically, almost as long as doing 4 separate reviews - the review text takes the least amount of time). From now on, I am not likely to be doing full series reviews - just one or two lights of a class.

HIDblue said:

EAnd as expected, you nailed the only criticism I have for the Neutron series...the dreaded "Squishy" clicky. It is by far the squishiest clicky/rubber boot cover combo I've ever felt. ... but I'm just not sure why Thrunite would put out such a "squishy" clicky...

Click to expand...

I'm experienced a lot of "squishy" clickies over the years (can't think of a better way to describe them). While noticeable, the Neutrons are not the worse I've come across - but it can be mildly irritating.

Oddly enough, I find lights with perfectly plat boot covers are more likely to have this problem. And hard surface covers are often even worse - the Tiablo A7 and Jetbeam E3P (the one with the stainless cover, not the rounded plastic boot cover) come to mind.

MAGnot said:

As a long time lurker here I've been awaiting your review regarding the Neutron 2C. I've previously purchased the 2A and just loved the light, so much so that I was considering the 2C version but read negative comments regarding the PWM issue. Now that you have confirmed the annoying PWM (your reviews have been a deciding factor in many of my torches), the 2C will be a pass....

Click to expand...

:welcome:

I am glad my reviews can help be a deciding factor - both for and against certain lights. Personally, I wouldn't go with a 110 Hz PWM light, but I know a lot of people here don't seem to be bothered by it. :shrug:

candle lamp said:

By the way, Can your 1A tailstand stably? My 1A can't, but 2A can do that stably. :shrug:

Click to expand...

My 1A has the most wobble of my four samples, but I suspect that's just random chance given the tailcaps are interchangeable.

But something else is odd - the wobble is much worse when clicked on. :thinking: Something I've never seen before - usually clicking-on improves tailstanding.

Yea that PWM issue on the 2C version is truly a deal breaker in my favorite battery form factor. I really thought Thrunite hit a homerun with this light, having a true low (with no preflash), nicely spaced modes, memory and being subtley beautiful. The XML emitter is very nice for every day use, Im finding, and is my favorite (until the next best thing). I don't understand why they have the PWM frequency so low on just the 2C verson, what are the benefits?

I was thinking that they commonize as many parts of the low-voltage head, but scaling up maximum voltage just enough to accommodate two brand new cr123.

For goodness sake, please don't lower the PWM frequency on the other three.

MichaelW said:

I was thinking that they commonize as many parts of the low-voltage head, but scaling up maximum voltage just enough to accommodate two brand new cr123.

Click to expand...

Ah, that's a little more doable - but it is still not a popular solution.

I would have leave this to the circuit experts to explain why, but I believe the real problem comes when you try to support 2x 3.7V Li-ion (which can over 4.2V to start, meaning you need more than 8.4V max - typically 9V to be safe).

If you just wanted to support 2x 3V CR123A, you could go a lot lower (i.e. a little over 6V, which is apparently easier to do in a multi-power circuit - especially regulated). But the few lights that have done this (the Tiablo A8 comes to mind, but I think there are some new Xeno lights as well) don't seem to do sell as well as those with full multi-power support. The problem seems to be that fresh CR123A cells can be a little over voltage under load, so you need to run them on a lower mode for a few minitues to drain them down to the point where they will activate on Hi. And of course, there's a risk someone will pop 2xRCR in there and blow the circuit. So, on the whole, manufacturers prefer to go with full 2xRCR support, which requires a whole new circuit.

No idea why they couldn't get the PWM higher on the 2C model's circuit, but it seems to be what it is stuck with. :shrug: