breathing test on different regulators

[scubapro50]

In general a piston 1st stage will require less maintance over time and will last longer. I own both types and they both have advantages and drawbacks. Now less compare apples to apples since both piston and diaphram regulators come in both balance and unbalance models. The Scubapro MK2 is one hell of a regulator but it is not balanced. My MK10 is a balanced piston and has lasted over 20 years with no major problems. I also own a Voit MR12 which breaths great on the surface but begins to drag as my tank emptys out at depth. I also own a new Mares Abyss (balanced diaphram) which is the best breathing regulator I have ever owned.

 

[JKSteger]

I'm looking forward to trying a Mares Abyss. I have been told by many of the more seasoned divers that I dive with that the Abyss is the best one they have every dove with. And that comming from guys/gals that have been diving for decades and have tried almost everything that has come thru the dive shop at some point.

Jeremy

 

[Land Locked]

This year I turned in my old Dacor Extreme, no comments from the peanut gallery - it was a darn good reg, for the Abyss. I'm extremely satisfied!

 

[The Kraken]

Hey, Jer, next time we dive, we'll get some depth and I'll let you give my a huff and puff or two on my Atomic.

the K

 

[Agent 47]

With a balanced second stage, I honestly can't imagine anyone being able to tell the difference between two seperate first stages unless the demand is very high. Remember, the only job of the 1st stage is to keep the LP side at the set IP. There's enough volume in the LP hoses however that with a balanced second stage, any first stage should be able to keep enough pressure on the LP side to keep the second stages performing well.

No one should be able to tell the difference in normal diving conditions between MK2 and ATX200 first stages assuming the IP is set the same and the same balanced second stages are used.

Of course, this is just theory but I imagine that any noticed difference is just in the diver's head.

Keep in mind, that regardless of the volume of air in the hose, if you remove even one cc of it, the pressure in the entire hose drops. If you're demanding more flow than the first stage can supply, obviously you'd expect an IP drop. As you've pointed out with high end regs in most normal situations this is likely going to be a non-issue. What comes into play here is how rapidly the first stage responds to the IP drop that will occur and cause the valve to open and probably things like how much of an IP drop it takes to start the valve opening, how fast and how far the valve opens (all the usual design considerations) and how much air is moving out of the other end of the hose, even internal volume of the hose to a degree, etc, etc. As long as you're within the limits of what the reg can do, you'd naturally expect that responsiveness of the first stage to have some noticeable impact on the feel of the thing. The diaphragm design seems like it'd be less mass to move back and forth, and there would probably be less friction involved? Just theorizing, but if that's actually the case then both types would probably have their place. At least up until the point where diaphragm technology is somehow pushed past piston technology in terms of flow, or they're both pushed so far that it just doesn't matter.

 

[Agent 47]

Oh...if the peanut gallery wants something to shoot at.....my first reg was an XR2/Spectrum combo.

 

[The Kraken]

Old saying, Henry . . .
"Ya don't get old by being a fool"

the K

 

[Agent 47]

God, I'm not sure how to take that. lol.

 

[The Kraken]

LOL !!!
Referring to gear.
If something stays around for a long, long time, in spite of marketing, technology or consumer perception, there has to be something inherently correct about it.

the K

 

[JKSteger]

Hey, Jer, next time we dive, we'll get some depth and I'll let you give my a huff and puff or two on my Atomic.

the K

Will do!

The thing that keeps going thru my mind is that I would have thought that a Scubapro MK20 with G250 should be one of the "better" setups. Now I know it's not Scubapro's "top" of the line but I've been told that internally it is very close to the MK25 which is the top dog (at least in piston) for Scubapro line.

I think that I should get the 1st stage checked out or something

The only other thing I can think of is that possibly it was "detunned" by the shop to avoid free flows. The tech knows that I frequently dive in water that is below 50F so he may have tuned down the IP to avoid freeflows.

...All this may just be "perception" in my head too.

Jeremy