Purchasing a NEW double hose regulator

[wd8cdh]

Hi Luis,

It's hard to tell exact sizes from photos but will the exhaust box of the Mentor fit on the intake box of a RAM?

Is the big hole in the intake box of the Mentor interchangable with a RAM body?

Also looking at the pictures of the new Mistral on the Flashback SCUBA site, its quite obvious that the second stage diaphram is similar in size to a single hose regulator. Do you know what parts in the Mistral are identical (same part number?) as Aqualung single hose parts?

Thanks,

[luis]

dale said:

Scubapro made an attempt at returning the D400 when they came out with the X650. Its actually a very good breathing second stage. Unfortunately they had a recall on it, which they took care of very well, but sales suffered and now its discontinued. Its all about $, I really believe if the industry thought there was a big market for a new double hose, all the manufacturers would be making them.

Actually, correct me if I am wrong, but my impression is the Scubapro introduced the X650 to replace the D400, because the D400 was a somewhat tricky for some techs to adjust. The X650 is mechanically very similar to most of the other Scubapro second stages (which in itself is a nice feature), were the D400 is a center balanced poppet design.

My impression is that the D400 can be adjusted to be about the easiest breathing regulator ever, with a relatively simple balanced poppet design. Part of the reason is that the exhaust is in the center of the diaphragm.

The X650could probably be adjusted to be very sensitive also but a major flaw was that they used a more conventional diaphragm with a separate exhaust. The distance between the two will cause a free flow in some positions if the water column is higher than the breaking suction that the regulator is adjusted to.


Now back to double hose regulators.
I agree that the market is not there, but that is not to say that the market could not be created with the proper diver training, education, and advertising. It would always be a specialized small sub-group of the diving community, but a double hose should be an available option to any main stream diver. Not just a small group of counter culture fanatics working in dark basements fixing old gear ... lol…actually I don’t work on regulators in my basement.

I feel that the Aqua Lung missed an opportunity when they introduced the new Mistral. IMHO the new double hose should have been more aesthetically pleasing (and perhaps try to capitalize a bit on the vintage look), but also the performance should have been far superior. At the same time the advertizing, dealer education, and customer education seem poor. I talked to several Aqua Lung dealers that were totally in the dark about the new double hose.

During the first year Aqua Lung did not share the service manual with the dealers with the policy that all service should be sent back to the factory. The intention was to keep track of any early malfunctions. I kind of understand their approach, but I think it kind of backfire in the way it was perceived.

Over all, from the design and marketing, I think the new Mistral project was a disservice to the double hose regulator community and other potential users.

[luis]

wd8cdh said:

Hi Luis,

It's hard to tell exact sizes from photos byt will the exhaust box of the Mentor fit on the intake box of a RAM?

Is the big hole in the intake box of the Mentor interchangable with a RAM body?

Also looking at the pictures of the new Mistral on the Flashback SCUBA site, its quite obvious that the second stage diaphram is similar in size to a single hose regulator. Do you know what parts in the Mistral are identical (same part number?) as Aqualung single hose parts?

Thanks,

Ryan Spence would have to answer questions 1 and 2. I would be interested in knowing also out of curiosity, but there is no practical reason since Mentor unique parts are not available.

It is very possible that the cases of the Mentor and the RAM may be interchangeable, but it would be part coincidence or they might have use a vintage regulator as a starting point. My understanding is that Aqua Lung lost all their drawings and tooling for the RAM in a fire. Therefore some dimensional similarities would have probably come from some reverse engineering.


One of my long term projects (later in the future) is to make a drawing for an insert into a RAM exhaust can for mushroom valve, similar to the Sportsways and Healthways. I personally don’t see a need to actually change our existing cans. I like the flat surface, it feel fine if it presses against my back (see pictures of double tanks with DIN fitting on different thread).



The first stage on the new Mistral is just a Titan first stage with a different ring on the front to attach the second stage and a different label. Everything else is exactly the same.

The new Mistral second diaphragm I think is a bit larger than any single hose Aqua Lung produces. And of course the second stage housing is unique to the new Mistral. The second stage demand valve looks exactly like several single hose demand valves, but I haven’t worked on any new Aqua Lungs second stages so I don’t know which one it would have come from. It might be unique, but it doesn’t look it. The lever does look like a slight variation of a standard single hose regulator.

[wd8cdh]

Thanks for the info Luis.

One of the reasons that I was asking is that I built a similar concept regulator to the new Mistral out of a Conshelf many years ago. The biggest difference was I mounted the second stage box to the first stage similar to the way the DA inhalation box is mounted to the regulator body and the IP was routed from the first stage to the second stage demand valve with a very short stainless steel tube and fittings rather than a rubber hose. I modified the venturi design to better work with the inhalation horn rather than a regular mouthpiece. I did use the stock single hose diaphragm but I made the exhaust valve from a wagon wheel and mushroom.

I made the exhaust box from a tuna can (with original label ;D ) just to freak out other divers. It breathed about as well as my DA (a little sluggish cracking pressure but easier exhaust) and except for the tuna can, it looked like it was factory made.

All in all, except for the double-hose mouthpiece and hoses them selves, I think I had about 20 bucks in the conversion. Although I felt that it needed a larger diaphragm, I dived with it for quit a few years. If I could find a cheap Nemrod box, mushroom valve and diaphragm, (anybody want to donate? ) I would rebuild it and probably use it as my primary regulator. I mostly dive with skinny doubles and triples so using a double hose would be great.

I think if a major manufacturer made something like this, and sold it at a reasonable price, they would make a profit. If the top and bottom box would also fit an Aqua Lung, they would have an even bigger market.

Ron Schroeder
Former Commercial diver, now Lazy Diver.

[luis]

wd8cdh said:

Thanks for the info Luis.

One of the reasons that I was asking is that I built a similar concept regulator to the new Mistral out of a Conshelf many years ago. The biggest difference was I mounted the second stage box to the first stage similar to the way the DA inhalation box is mounted to the regulator body and the IP was routed from the first stage to the second stage demand valve with a very short stainless steel tube and fittings rather than a rubber hose. I modified the venturi design to better work with the inhalation horn rather than a regular mouthpiece. I did use the stock single hose diaphragm but I made the exhaust valve from a wagon wheel and mushroom.

I made the exhaust box from a tuna can (with original label ;D ) just to freak out other divers. It breathed about as well as my DA (a little sluggish cracking pressure but easier exhaust) and except for the tuna can, it looked like it was factory made.

All in all, except for the double-hose mouthpiece and hoses them selves, I think I had about 20 bucks in the conversion. Although I felt that it needed a larger diaphragm, I dived with it for quit a few years. If I could find a cheap Nimrod box, mushroom valve and diaphragm, (anybody want to donate? ) I would rebuild it and probably use it as my primary regulator. I mostly dive with skinny doubles and triples so using a double hose would be great.

I think if a major manufacturer made something like this, and sold it at a reasonable price, they would make a profit. If the top and bottom box would also fit an Aqua Lung, they would have an even bigger market.

Ron Schroeder
Former Commercial diver, now Lazy Diver.

Do you have pictures?

[wd8cdh]

No, but I will take some soon. I have had it packed up for some time because the old hoses were shot.

Ron Schroeder
Former Commercial diver, now Lazy Diver.

[SeaRat]

luis said:

dale said:

Scubapro made an attempt at returning the D400 when they came out with the X650. Its actually a very good breathing second stage. Unfortunately they had a recall on it, which they took care of very well, but sales suffered and now its discontinued. Its all about $, I really believe if the industry thought there was a big market for a new double hose, all the manufacturers would be making them.

Actually, correct me if I am wrong, but my impression is the Scubapro introduced the X650 to replace the D400, because the D400 was a somewhat tricky for some techs to adjust. The X650 is mechanically very similar to most of the other Scubapro second stages (which in itself is a nice feature), were the D400 is a center balanced poppet design.

My impression is that the D400 can be adjusted to be about the easiest breathing regulator ever, with a relatively simple balanced poppet design. Part of the reason is that the exhaust is in the center of the diaphragm.

The X650could probably be adjusted to be very sensitive also but a major flaw was that they used a more conventional diaphragm with a separate exhaust. The distance between the two will cause a free flow in some positions if the water column is higher than the breaking suction that the regulator is adjusted to.


Now back to double hose regulators.
I agree that the market is not there, but that is not to say that the market could not be created with the proper diver training, education, and advertising. It would always be a specialized small sub-group of the diving community, but a double hose should be an available option to any main stream diver. Not just a small group of counter culture fanatics working in dark basements fixing old gear ... lol…actually I don’t work on regulators in my basement.

I feel that the Aqua Lung missed an opportunity when they introduced the new Mistral. IMHO the new double hose should have been more aesthetically pleasing (and perhaps try to capitalize a bit on the vintage look), but also the performance should have been far superior. At the same time the advertizing, dealer education, and customer education seem poor. I talked to several Aqua Lung dealers that were totally in the dark about the new double hose.

During the first year Aqua Lung did not share the service manual with the dealers with the policy that all service should be sent back to the factory. The intention was to keep track of any early malfunctions. I kind of understand their approach, but I think it kind of backfire in the way it was perceived.

Over all, from the design and marketing, I think the new Mistral project was a disservice to the double hose regulator community and other potential users.

Luis,

I agree that this New Mistral was a disservice to the double hose community. I came to the conclusion that this regulator was designed for single-tank diving only, as when I tried to put it onto my doubles, it would not fit with the valve orieted with the on-off knob up. When I re-oriented one of my sets so it would fit, then the regulatory actually hurt as it hit my back with my twin 50s using the old military-style harness. So they made some assumptions that put it into a different type of diver that myself--probably hoping to have single tank uses who had a BC built onto their backpack in the modern way. I simply could not get it to work in other configurations.

John

[SeaRat]

Ron,

I also would enjoy seeing photos of your regulator.

John

[luis]

searat said:

I agree that this New Mistral was a disservice to the double hose community. I came to the conclusion that this regulator was designed for single-tank diving only, as when I tried to put it onto my doubles, it would not fit with the valve orieted with the on-off knob up. When I re-oriented one of my sets so it would fit, then the regulatory actually hurt as it hit my back with my twin 50s using the old military-style harness. So they made some assumptions that put it into a different type of diver that myself--probably hoping to have single tank uses who had a BC built onto their backpack in the modern way. I simply could not get it to work in other configurations.

John

That shouldn’t be a surprised, I don’t think anyone has built that style of double tank valve in at least a decade maybe two. All the new double tank valves seem to be isolation valves with two DIN outlets on top of the tanks. Not really intended for a double hose regulator.


I don’t think they gave it too much thought at the hole system.

I posted on ScubaBoard in response to a post of an Aqua Lung regional rep. I made the comment that they dropped the ball with the new Mistral and he totally agreed.

www.scubaboard.com/forums/fins-masks-snorkels/210405-aqualung-slingshot-review.html

Oh you may like that thread. It is actually about Aqua Lung new “weird” fins.

[SeaRat]

Now you're making me feel "vintage," Luis. The Aqualung Slingshot fins are interesting, but as you know I have a bit of a prejudice on fins. I think they need a "scoop" on the end--it doesn't look like Aqualung designed that feature into the Slingshot Fins.

John