I was wondering if anyone had a good comparison of the two as I can’t find much more than a listing of specs and while I’m tying it will be a while before I’m far enough down the rabbit hole.
Thanks
Bump
From what I (think I remember) reading in past posts… the A has a removable brass shelf (which the MCPCB sits on) and can be raised or lowered for easier modding. While the B has the shelf machined into the body- so slightly better heat transfer out to the B’s host body perhaps, but not as easy to mod.
I JUST got the B version with the Osram CULPM1.TG and new ramping driver 
So I am hoping it’s a little “throw monster” I plan to use on an AR15 mount with a FET pressure (remote) switch. Yes… it will also be a “heat monster”… but on the gun used for 30 second views (or shorter) time-frames I’m not concerned. Coyotes beware!!!
I just need to wrap up deer hunting this next week so I have time (during upcoming cold, nasty weather) to build the FET tail pressure switches out and do some field testing in Late Feb.
I don’t have either but believe I read the same. S21A is like S2/S2+ and S21B is like S3. Interested to hear your thoughts on the CULPM1 and ramping driver!
does the ramping driver come as stock?
what driver is it? any more info? thanks.
Today I put together my C8+ with the Osram on my AR15 WITH my FET pressure switch (from my old Sofirn C8F 18650 mods- the tail cap lego’ed with the C8+). This is DEFINATELY going to be my NEW hunting light for sure! I am WAITING for it to get dark 
I also played with the S21b some and it’s also looking good (in daylight, next to the C8). I haven’t figured out the “ramping” yet, but it came out of the box configured for 100% ON. So given I HAD a pressure switch made-up already, I could have mounted it on my rifle WITH the switch. I’m SURE it would be a great performer on any rifle out to 300-400 yards from what I already saw today. But the S21b is not as easy to mount to a rifle’s scope or AR rail— as it can’t use standard rifle scope rings (* the C8 IS A PERFECT FIT in 1” rings though). The S2+ with the SST40 (I also have and will test for shorter range/wider flood rifle use) can be easily “shimmed” to fit 1” scope rings too.
Given all these models are available from Convoy (built and ready to use with whichever driver/emitter I specify), Convoy is going to be my go-to for rifle lights this year. And I have asked Simon already for an S2+ with an Osram emitter and NO thermal management. We’ll see what he says.
As I’m using these on rifles for short-time use I’m not worried about temps… BUT I also understand that these configs are not warrantied by Simon as they are “hot-rods” (literally). I probably will NOT use these lights (especially the S2+ and probably S21b) as hand-held lights. But maybe the C8+ can be run in the hand by those who can manage the heat (and the risk of burning out an emitter if run too hard/long).
More to come after I get some time outside with them… hoping tonight if fog stays away!
-The ramping driver is only available with the e-switch lights, such as M21C-U. The S21A and S21B come with biscotti UI which is programmable up to 12 levels, or a simple 4 mode non-programmable UI. Maximum 6 amp output for 3volt leds, less for 6v leds. (Old info - corrected by Zappaman, below, thanks!) Check out Simon’s official Convoy store, lots of lights, lots of options: https://convoy.aliexpress.com/store/330416?spm=a2g0o.detail.100005.2.3f94473dZczKKi [quote=virencelights] does the ramping driver come as stock? what driver is it? any more info? thanks. [quote=hodor]
I don’t have either but believe I read the same. S21A is like S2/S2+ and S21B is like S3. Interested to hear your thoughts on the CULPM1 and ramping driver!
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dmsoule…
Your post above is correct for standard stocking lights up until very recently. Both Funstastic and myself have several tail switch lights with newer “ramping” drivers (although… I confess I’ve had mine a few days and don’t know how to ramp them yet) 
But Simon is calling the new 8A driver (for both my C8+ and S21b— for use with the Osram) a “ramping driver” and they output 8A nicely —matching the Osram’s efficiency at peak output well.
AND… I JUST 20 minutes ago went out with my C8+ (Osram/8A ramping driver) mounted on my AR15. I have a dark field about 400 yards to the trees in the back—- Wow, wow, wow!!!
It’s drizzling here tonight, but I could have EASILY picked off a coyote (with the right gun) tonight with this set-up at that 400 yards (through my scope of course and given a good rest/low wind) 
The Osrams are real game changers for smaller lights with thermal management OR these hot-rod C8+’s (and S21b’s) that Funtastic and I are using on LONG-range rifles. Reviews to come soon!
Cheers Ears!
Did you figure out ramping Zappaman? I don’t see C8+ or S21B with ramping. I prefer ramping and don’t care for just side switch. M21c with dual switch like L6 would be great.
So the ramping is still a mystery to me…sorry.
But as I am using these lights (and an S2+) for gun use… AND these all come out of the box already set for 100% on- I’ve not tried to change modes. They will double click down to about 1/2 output (if you click it fast). But clicking on/off two times a second— they ALWAYS come on in turbo and I LOVE THAT!
Sorry, I should take the time to figure it out, and eventually I will. But if you want a gun light these two Osram loaded S21b and C8+ lights (and the SST40 in my S2+) are the cat’s meow for throw and decent flood.
I took the S21b out last night in total darkness and lit up an old barn out in a field at 200 yards easily seen with the naked eye. I’d probably call it a 300+ yard rifle light WITH good glass (scope) for coyote hunting. But mounting that one is tricky as it’s 1 1-1/16th” in diameter. Just a bit too wide to put in 1” scope mounts (darnit! -have to get the dremel out)
I also ran the S21b next to the S2+ with this same driver (*type of driver, it’s actually not the same 8A version used in the S21b or C8+ according to Convoy, but it runs the SST40 well). The S2+ has the same 100% on feature I asked for (“ramping driver”) and that little light was getting out about 150 yards to the naked eye. And the S2+ can be easily shimmed to fit into 1” scope rings and mount easily on an AR for a “killer” hunting rig for pigs, or coyotes out to maybe 225 yards (a lot depends on the glass in scope of course).
I do love my hand-held ramping lights like you though… and the new Convoy M3C (I got with these latest rifle lights) now ramps and… * it can run full speed for 5 minutes without dropping down. Much larger light, not for guns. The ramping is slower to initiate compared to other lights I have too… but once you get used to it- it’s a very cool flood monster with about 150 yards of throw.
I just need time to figure out and review some of these
I've tried the Convoy S21A with SST40 LED and the S21B with SST40 & CULPM1 LED. (12-mode driver)
Physically, the Convoy S21A looks like a 21700 battery version of the Convoy S2+ (which uses 18650), while the Convoy S21B looks like a 21700 battery version of the Convoy S11 (which uses 26650 battery).
The S21A uses an OP reflector whereas the S21B uses an SMO reflector.
S21A (SST40) and S21B (SST40) beam look fairly similar, while the S21B with Osram PM1 LED is more throwy. I believe the S21B with Osram PM1 I got is just the 6Amp driver, and not the ramping 8Amp driver though.
(I haven't found the link to the S21B with 8 Amp driver, can you point me to it, Zappaman?)
Convoy S21A (SST40 5000k, 12-mode, 6-Amp driver) vs Convoy S21B (SST40 5000k, 12-mode, 6 Amp driver):
(Left is S21A, Right is S21B)
Convoy S21B (Osram CULPM1, 6 Amp driver) vs Convoy S21B (SST40, 6 Amp driver)
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