The New Atomic TFX
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Geo7
Contributor
I think with all of us watching he is trying to do a thorough write up, and do our anticipation justice...
OP
I am also married...
After not two, but four hours in the pool yesterday, and 300+ CF of gas with eight second stages, and home to clean the chlorine out of my wing, I was reprimanded after tabulating numbers at the dinner table..
Tomorrow, my good friends...
But they're pretty damned sweet
(both the reg and my wife).
After not two, but four hours in the pool yesterday, and 300+ CF of gas with eight second stages, and home to clean the chlorine out of my wing, I was reprimanded after tabulating numbers at the dinner table..
Tomorrow, my good friends...
But they're pretty damned sweet
(both the reg and my wife).
I just assumed your lungs were bleeding from poor performance of the reg.I am also married...
After not two, but four hours in the pool yesterday, and 300+ CF of gas with eight second stages, and home to clean the chlorine out of my wing, I was reprimanded after tabulating numbers at the dinner table..
Tomorrow, my good friends...
OP
Well, thanks to my good friends at Marin Diving Center (shameless plug!) with their donation of unlimited gas and exclusive use of the pool, I was able to spend hours with the Atomic Aquatics TFX second stage, and then compare it side-by-side with many of my fave's. I of course ran the TFX alongside its center balanced historical sisters, the D400 and the D420. Recall that the TFX shares a design heritage with the D400, by way of Dave Toth, formerly of Scubapro and now a big part of Atomic. The D420 was Scubapro's resurrection of the center-balanced valve, covered ad nauseum here: D420! How about that?
I also compared with some regs also reviewed recently here:
D420! How about that?
A lot of divers on the board are hardware fanatics, wanting to extract the last ounce of performance from their equipment. A newer diver would be better to concentrate on ease of use, ease and cost of maintenance, and reliability. Have you read this thread in its entirety? I get the impression...
For testing, I had a 12-foot deep dive shop pool, so I'm limited to thin gas evaluations. None of the high-density comparisons that we did in Key Largo as part of Regulator Geeks III. Nonetheless, I compared:
- leisurely standard position noodling along
- max effort swims with heavy breathing in the standard position
- vertical position performance
- performance on my back
- incidence of wet breathing when inverted head down (or in the case of the TFX and D400, "inverted plus" to about 210 degrees from the vertical, which places the exhaust leaflets up and horizontal.
Just like ScubaLab and their annual entries in Scuba Diving magazine, this evaluation is a personal comparison wholly apart from the flow and work numbers in an ANSTI loop. I'll stick the TFX on my flowmeter for the next Regulator Geeks discussion night. Yesterday was just one guy's opinion and should be taken with a grain of salt. You all probably know by now of my personal bias towards center-balanced valves, so observer bias is a clear and present danger.
Just as with the Spiegel Grove dive at 120 feet, ALL the regs did fine! They're all solid, well known models, so why wouldn't they do well? If that's all you need to not drop $2,200 on a TFX, just walk away. There are none of them I wouldn't take on a deep dive, and maybe only one I would be concerned with on a tech dive in heavy current (sadly, my heretofore favorite D400). But for recreational diving, they're all solid.
What does matter? TUNING!!!!!
You can make any generic reg do pretty well if it's tuned to the low end of specification cracking effort and the components are corrosion-free and recently lubed. If not, let the horror stories begin...
Therefore, ALL of the regs were "hot-tuned" to the low end of mfr specification cracking effort (abbreviated in the tables as C.E.).
Here's your starting data:
The TFX is absolutely exquisite when noodling along in the standard diving position!! Even accounting for observer bias, it was the star.
Flow was smooth.
Flow acceleration with a big breath was smooth.
Those multiple outlets and directed exhaust flow worked! Normal exhalation was indistinguishable from an Atomic, and even better than my G250 and G260. Surprisingly, my fave from the recent Cayman Brac trial, the C370, had a little rougher feel to it, and a side-by-side test gave slightly differing results from the day to day switches on my last trip.
Still, they're all great regs. But the TFX was smooth!
Negatives? Almost none.
The D420, I've finally conceded, really does need a higher cracking effort than its center-balanced valve would suggest, because of that aft facing exhaust valve. And while light exhalation favored that regulator over ALL the others, light inhalation with a 1.2" cracking effort, even offset by the diaphragm's low position in the water wasn't quite as good as all the other regs. Picky stuff.
But I did learn something right away...
Tuning a TFX to 0.7" makes it SO twitchy. It would freeflow at the drop of a hat out of my mouth. Turning the Venturi vane to Min didn't help. Standard technique for shutting off freeflow (inverting the reg mouthpiece down, and then slowly turning it upright as it fills with water) didn't work. I had to slowly turn the reg on its side and allow case gas to leak out the exhaust valve and tee, and fill with water with the mouthpiece horizontal. It would start flowing in any other position. That was clearly untenable for standard diving, where leaving it in the standard secondary position might trigger the valve as you swam.
So for the third set of tests, I retuned the TFX to 1.1". That's still below where the factory set it (at 1.3"), and I don't know what spec cracking effort limits are, but that change made it behave much better, with almost no discernable effect (see below).
What else did I learn?
There were ZERO mask bubbles with this reg, with the G260 and (almost) with the Atomic T2x with an added M1 wide exhaust tee. In the standard diving position, looking 30 degrees down or lower, it was delightful. In contrast, the D420, with its narrow case shape, was quite bubbly (though this would not be noticeable with almost any forward motion), and the large case standard shapes (G250, Signature) were slightly worse. Interestingly, the curved exhaust tee's touted by Scubapro for their reduction in exhalation WOB, shared by the C370, G420 and S620Ti (not tested) all had modest or worse bubbles in front of the mask when stationary. As you'll learn below, ALL regs get much worse as soon as you look up from a 30-degree head down position.
When one moves from standard diving position to a vertical hover looking straight ahead, case geometry changes things slightly.
The posterior exhaust valve of the standard barrel regs and the D420 now moves lower in the water column. The exhaust tee of all regs moves right below your chin. The diaphragm position changes, also subtly influencing breathing effort:
Now, with a high cracking effort and a diaphragm that has moved up from its lowermost position, the D420 performance begins to fall apart. While exhalation remains good, high flow inhalation is palpably worse than the others. Meanwhile, even with an increased cracking effort between trial sets, the TFX remained as good as any reg at both light and heavy inhalation.
But oh! The bubbles! As you might guess, EVERY reg sucked when vertical in the water column. No surprise there.
See next post...
OP
Now it's time to stand on our heads...
If you think about it, every regulator breathes wet when its exhaust valve is horizontal and facing up.
Every regulator.
However, in standard case designs, that position (looking approx. straight down) is never followed by a forward roll. In other words, whatever water dribbles in during that move accumulates in the bottom of the case near the diaphragm. And the next time you look back up, you flush the water out with your next couple of exhalations.
So in my inverted trial at the 180 degree position, all the regs were completely, or almost completely dry.
For the same reason, when I put the D400 and TFX in their worst position (and who dives 210 degrees past the vertical?) the water entry that is shared by ALL regulators when their valve is uppermost went straight to the mouthpiece. So if you're weird enough to dive past inverted and hold that position, the TFX and D400 are quickly wet breathers in the worst position to keep water out of your trachea. But so what.
If you're weird enough to admit water to a standard reg by the simple action of looking straight down, and then continue with a forward loop, you'll inhale a teaspoon of water, too!
In other words, the wet breathing test did not disfavor any particular reg. And when not hot tuned, wet breathing should be even less.
And when you do something slightly less odd and look up a bit, the TFX and D400 are truly unique.
Think taking a pic of a shrimp on the underside of a ledge. Or getting the really good fish shots: from below their level in the water.
When you carry it to an extreme and lie completely on your back, the differences become obvious. A coaxial diaphragm and exhaust valve set to the same cracking effort as a standard reg whose exhaust valve is lower in the water when looking up performs markedly better:
Increasing the cracking effort of the TFX to 1.1" provided here the only solid indicator of a minor decrement in light breathing performance. Big deal.
And when your cracking effort is higher (D420) looking up sucks. Literally. To open the valve, you need to suck the diaphragm down to exhaust valve level (0" with TFX; 1.25"+ with aft-placement cases) and then add cracking effort. It can be 2" or more effort with every breath.
The TFX is truly an all-position regulator which maintains its smooth breathing in ALL positions.
Little points? Bubble noise isn't a big thing for me. I don't ever notice it. But it is for some of you. And an interesting feature perhaps of those flexible silicone exhaust tees on the TFX is a subtle change in the timbre of exhaust bubbles. The reg was quiet and lower pitched. In contrast, when I paid attention to it, my recent favorite C370 was noisy and higher pitched. I hope paying attention to that doesn't now screw up my diving going forward, lol!
In summary, for average diving in a variety of situations (no thick air tests, yet), the TFX is on a par with every reg I own. It is superior for quiet breathing. The engineers appear to have solved the problem of a low exhaust valve by providing exit paths that almost completely eliminate exhalation effort. And we now have the return of almost the only reg (think also Hollis 500se and Poseidon Jetstream/XStream) where head position in the water doesn't matter. If you're a "peeker" when you noodle around the reefs, this reg is an absolute star! If you're an extreme diver, this valve and configuration appear from initial heavy breathing tests to more than meet your needs.
More to follow when the GoFundMe that I'm sure you're all going to contribute to, gathers enough funds for a free airplane trip for me to do a "scientific" test in Key Largo on the Spiegel Grove at depth.
If you think about it, every regulator breathes wet when its exhaust valve is horizontal and facing up.
Every regulator.
However, in standard case designs, that position (looking approx. straight down) is never followed by a forward roll. In other words, whatever water dribbles in during that move accumulates in the bottom of the case near the diaphragm. And the next time you look back up, you flush the water out with your next couple of exhalations.
So in my inverted trial at the 180 degree position, all the regs were completely, or almost completely dry.
For the same reason, when I put the D400 and TFX in their worst position (and who dives 210 degrees past the vertical?) the water entry that is shared by ALL regulators when their valve is uppermost went straight to the mouthpiece. So if you're weird enough to dive past inverted and hold that position, the TFX and D400 are quickly wet breathers in the worst position to keep water out of your trachea. But so what.
If you're weird enough to admit water to a standard reg by the simple action of looking straight down, and then continue with a forward loop, you'll inhale a teaspoon of water, too!
In other words, the wet breathing test did not disfavor any particular reg. And when not hot tuned, wet breathing should be even less.
And when you do something slightly less odd and look up a bit, the TFX and D400 are truly unique.
Think taking a pic of a shrimp on the underside of a ledge. Or getting the really good fish shots: from below their level in the water.
When you carry it to an extreme and lie completely on your back, the differences become obvious. A coaxial diaphragm and exhaust valve set to the same cracking effort as a standard reg whose exhaust valve is lower in the water when looking up performs markedly better:
Increasing the cracking effort of the TFX to 1.1" provided here the only solid indicator of a minor decrement in light breathing performance. Big deal.
And when your cracking effort is higher (D420) looking up sucks. Literally. To open the valve, you need to suck the diaphragm down to exhaust valve level (0" with TFX; 1.25"+ with aft-placement cases) and then add cracking effort. It can be 2" or more effort with every breath.
The TFX is truly an all-position regulator which maintains its smooth breathing in ALL positions.
Little points? Bubble noise isn't a big thing for me. I don't ever notice it. But it is for some of you. And an interesting feature perhaps of those flexible silicone exhaust tees on the TFX is a subtle change in the timbre of exhaust bubbles. The reg was quiet and lower pitched. In contrast, when I paid attention to it, my recent favorite C370 was noisy and higher pitched. I hope paying attention to that doesn't now screw up my diving going forward, lol!
In summary, for average diving in a variety of situations (no thick air tests, yet), the TFX is on a par with every reg I own. It is superior for quiet breathing. The engineers appear to have solved the problem of a low exhaust valve by providing exit paths that almost completely eliminate exhalation effort. And we now have the return of almost the only reg (think also Hollis 500se and Poseidon Jetstream/XStream) where head position in the water doesn't matter. If you're a "peeker" when you noodle around the reefs, this reg is an absolute star! If you're an extreme diver, this valve and configuration appear from initial heavy breathing tests to more than meet your needs.
More to follow when the GoFundMe that I'm sure you're all going to contribute to, gathers enough funds for a free airplane trip for me to do a "scientific" test in Key Largo on the Spiegel Grove at depth.
Thank you, @rsingler! So much goodness!
And, of course, mine still hasn't shipped so now it's even worse than Christmas Eve!
One question that is still unanswered (I think). Will the standard Atomic 1st stage tool work to get the cap off to allow adjustment of the cracking pressure?
Looking at pictures, it looks like the TFX cap has 3 holes for pins of a wrench to fit into.
The Atomic 1st stage tool has 3 pins to insert into holes.
I.e. pictures suggest that the 1st stage tool *could* work, but no way to tell if the actual dimensions match.
And, of course, mine still hasn't shipped so now it's even worse than Christmas Eve!
One question that is still unanswered (I think). Will the standard Atomic 1st stage tool work to get the cap off to allow adjustment of the cracking pressure?
Looking at pictures, it looks like the TFX cap has 3 holes for pins of a wrench to fit into.
The Atomic 1st stage tool has 3 pins to insert into holes.
I.e. pictures suggest that the 1st stage tool *could* work, but no way to tell if the actual dimensions match.
OP
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