Regs for tech diving .?.?.?

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stefusa

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I'm a Fish!
I did a search but not find the answers...
what are the best choices of regs 1st and second stages for Tech diving?
I already know that scubapro is probably the best choice...
I will be more specific....
I am looking for a tech setup, also DIR compliant (the BIG question about the swivel on the first...)
I know that the hose routing is pretty important.. and that a membrane first stage is probably prefered (no water inside and less moving parts).
I know also that many DIR divers dive the MK25..
I have heard good stuff about the MK17..
For the second stage, should I really be able to open it underwater :11: ??
again, i heard good stuff about the D400, X650 and S series...

PS: I would like more than "I dive MK25/X650 and I love it..."
What are the pros and cons? why did you bought this one???


Thanks
 
FWIW the X650 is not DIR Compliant. The reason being is that you would be unable to take it apart underwater, without tools, to clean any debree in it.

I'm unfamiliar with a "membrane first stage". Can you elaborate on that?

Their are three types of first stages that I'm aware of. They are unbalanced piston, balanced diaphragm, and balanced piston.

An unbalanced piston regulator are typically the bottom of the line regulators, such as a Scubapro MK2. There is absolutely nothing wrong with an unbalanced piston regulator for recreational depths. Many manufacturers make some unbalanced first stages that are tanks and nearly indestructible. That said, they will only serve one purpose well in technical diving and that is to use them on shallow stage bottles and/or decompression bottles. The reason for this is because the deeper you go, the harder they become at breathing from. This can cause some extra task-loading at depth that you really wouldn't need.

Balanced diaphragm regulators are very popular in many realms of diving and are the most common type of regulator around. It uses a rubber diaphragm to direct gas through the first stage. The bad thing about that is the potential of the diaphragm failing, but you don't see that happening to often, and even less likely in regulators that are submitted for regular servicing, as specified by the manufacture. An example of a balanced diaphragm first stage would be the Scubapro MK17, Oceanic CDX, Salvo SR1 and SR2, Apeks DS4, etc. It's also worth noting that most balanced diaphragm regulators are environmentally sealed, which makes them very useful in colder water environments, such as ice diving.

The balanced piston first stages are tanks as well. These use a piston to direct gas through the first stage, but a major difference between them and an unbalanced piston is the pressure on both sides of the piston is equal. This makes it ideal for deeper dives, where having a good, constant, easy breathing regulator helps cut down on the task loading. An example of a balanced piston regulator is the Scubapro MK25.

A Scubapro MK25/S600 combo is an excellent work horse of a regulator. The only thing that I do not like about them is the turret on the MK25.

Unfortunately with your question you are going to get mostly opinions on what the best regulator is. There isn't a good answer. You could go read the numerous articles in scuba diving magazine about good regulators, but most of the companies being tested in those articles paid scuba diving magazine to do so, and it leaves out hundreds of other models out of the article.

I have four regulators. I have two Salvo SR1 first stages with Scubapro G250 second stages for my doubles, an Oceanic DX4 first stage w/ Oceanic GT second stage for my single tank dives, and a Aeres A1 for my decompression tank. If I was to buy another regulator today I would probably buy a Salvo SR1, but not necessarily because it's the best regulator out there, but because of the availability of service parts. That's not to say that I don't think the Salvo regulator isn't a good regulator, it is and I'll continue to do business with them.
 
I wouldn't say that one brand or another is the best choice for technical diving, a low end scubapro will not perform as well as a high end from another company. It's all about the performance and features of the reg.

Personaly I love the DiveRite RG2500 regulators. Those are what I use on my doubles and stage. They are balanced diaphragm regs, perform outstanding at any depth, all around great performers. You can get a cold water kit for them if that is the type of diving you'll be doing. Comes standard in DIN. The 1st stage has a swivel for the low pressure ports which really helps with the hose routing on the regs, I don't see any reason that a swivel on a high end 1st stage is a 'bad idea' for tech. I'm sure some will say it adds another failure point, nitpicky IMO. I'm not fresh up on the DIR 'standards' they usually preach apeks though, they change their mind every few months anyways.
The second stage is a pneumatically balanced downstream. And if you had to open it under water the retaining ring for the cover unscrews easily if you so inclined to do so.
 
amascuba:
.. This can cause some extra task-loading at depth that you really wouldn't need...



.. This makes it ideal for deeper dives, where having a good, constant, easy breathing regulator helps cut down on the task loading...

What depth is this? I think it is important that this depth is also known so that if there is no intention to to to this depth, unbalanced regs could be used.
 
amascuba:
I'm unfamiliar with a "membrane first stage". Can you elaborate on that?

Membrane = Diaphragm
 
"I already know that scubapro is probably the best choice..."

Sounds like you've already made up your mind.

You can't go wrong with Apeks regs. I have atx 200's for backgas and ds 4's with atx 40's and 50's for deco and stages.
 
I have Apeks TX50 second stages paired with DS4 first stages on my doubles.

Why did I get these particular regs? Well, they have an established track record for durability and reliability. Generally I would say that a simple proven design without flashy features that might break is a better choice for regulators than some new whiz bang design. That new whiz bang design may prove over time to be a better choice, buth then again it might not, I would rather let others find this out. The regulators I take deep or into a cave are pretty important so I made an extremely conservative choice.

Having said all of that, I would think that any high end regulator from one of the major manufacturers would be fine. ScubaPro, Aqualung, Apeks, Zeagle, Atomic, DiveRite, and many others would serve you well. They each have different features that can tip the balance.

I personally like the metal adjustment knob, and the "dive / pre dive" mechanism on the Apeks.

Mark Vlahos
 
I personally have SP MK25/S600 and Apex DS4/Tx50 &xtx50
I dont care for the turret on the SP but the bottom port makes hose routing for doubles nice. I like the DS4 because house routing is fine and theyre small. I also prefer the DS4 because theyre sealed unlike the piston. As for the second stage, the s600 is nice and small so it fits under your chin quite nicely, the xtx is slightly larger but still nice. I would only use the TX reg as a primary as its pretty big. All in all I prefer the TX 50 over the other two however I do prefer Scuba Pros mout piece much more. I am surprised that no one has said Atomic, they are very nice regs and can be had without a turret. Several Gue trained divers around me all dive Atomic and again that bottom port makes hose routing real nice. The only thing from preventing me from buying an atomic is that to enviro seal it, you use alot of expensive O2 grease...given I already have the grease, the tool, and the bands...
 

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