Vintage Double Hose

Ok, I have done a search for the last hour on the forum to see if questions I have were answered. I don't find them, and I'm sure someone knows exactly where they are... so.... First of all, most of you folks know I mainly have dove with my Da since 1970's while underwater metal detecting. Now, since the Pheonix is getting turned loose and repro stuff you guys make... I am starting to become a convert and more interested in getting a set of gear to match everything together. But, anyway, here is my first question. I finally found a RAM and bought it, s/n 5228, square lable. So, this regulator is balanced, and what is the difference between this RAM and my old DA as far as that means breathing wise and internal components? Please be patient with me guys, I have no idea, I just always hooked my Da up and went diving. My DA breathes great, what would I expect after the RAM was tuned up and tweaked vs my DA?

This is not a silly question at all…..I know there are several others on the forum that will do a better and more technical description of balanced 1st stage than I do……But in a nutshell on a balanced 1st stage the pressure is “equal” or “balanced” on both sides of the HP seat at all times. The DA is an unbalanced 1st stage and the cylinder pressure is maintained only on the top side of the HP seat.
On a RAM you should never experience any difference in breathing resistance between full cylinder and empty cylinder due to the fact that the pressure is continually balanced above and below the HP seat with every breath.
This also makes a HUGE difference when you dive deep. On a DA you will feel the difference (ask the bottom dwellers at Wazee) at depth. Using a RAM you will feel very very little, if any at all.
There are a couple of other factors when you set up a RAM that allows for a bit easier breathing……The Phoenix nozzle that Luis has designed lets you put a balanced 1st stage on DA’s. And once your DA has a balanced 1st stage there is NO advantage to having a RAM as their 2nd stages are identical.
JMO….Your results may vary……Ramble on.

OMG... I get it now. I didn't know that a DA would then be balanced w/ a phoenix. Jesus, I hope Lewis pateneded that thing! One more thing. Will I be able to use a 3000 psi tank w/ my updated DA? Or should I convert the RAM to a Pheonix to accomodate the tank pressure.

The Phoenix nozzles will all use the USD late model high pressure yoke and the internals are all current Conshelf/Titan so using high pressure cylinders should be no problem at all.

If I may add, the Phoenix first stage nozzle/ body is just a Royal Aqua Master first stage in a somewhat different packaging. When a DA first stage is replaced with a Phoenix, the regulator is then a RAM (from a mechanical function standpoint).


As Bryan mentioned, there are several advantages to a balanced first stage:

1st) the intermediate pressure (IP) is constant and not affected by the changing tank pressure.

2nd) since the IP is constant, the IP can be increased to fine tune it against the second stage spring force.

3rd) the balanced first stage also has a lager volcano first stage orifice allowing more air flow under heavy working conditions. In the unbalance DA first stage, a large volcano orifice would cause the intermediate pressure to change more as the tank pressure changes.

The combination of the three items mentioned can help a properly tuned Royal to perform better than a DA at any tank pressure and at any depth.


BTW, any Royal can be used with tank pressures up to 3000 psi. With the heavy yoke from the last generation of RAM’s or the Phoenix you could easily use them with 3500psi tanks.

I didn't know that information, or didn't study up on it anyway. So, diving with my DA in shallower water treasure hunting, I never really got to the point of running out of air, or feeling it too badly when the tank pressure became reduced. If I ever needed more air, I just stopped digging and turned over on my back, therby giving me all the air I wanted. It probably became a normal sensation to me. When wreck diving, I used a single hose of course. This is interesting, and I'll be most interested getting my DA completed. Luis, thank you for re-inventing the double hose and all you guys' hard work. I'm enjoying myself with this group. It has been a very long time since I have had this much fun and diving without having to wear pink gear.

Update the RAM or DA to Pheonix spec. couple that with the new minelab detector, and you will have two things most divers dont get. "treasure and pleasure" (Bob Marx)

You bet! And just wait till he sees the Pheonix! He may go back to a double hose!!