Talk to me about the Conshelf XIV Supreme

[halocline]

I definitely get what a lot of you are saying. There have been a ton of "improvements" made throughout the years that are nothing more than marketing ploys or cost-cutting measures.

Yay, you're learning!

The MK17 EVO now has a completely dry chamber. I like that. I don't like salt and chlorine water getting into my first stage and corroding important pieces.

And the A700 is all-metal. Just like the original 2nd stages.

The MK17 does have a sealed ambient chamber, but that's hardly the only place salt and chlorine will damage a regulator if not removed through soaking.

The A700 is a metal body, but it's smaller and has more aggressive venturi assist than the old metal case 2nd stages. Those two things definitely change the character of how it breathes. So it's not just like the old ones.

That said, the MK17/A700 is a good regulator and it will serve you well. The MK5/109 is a good regulator and would serve you well. Many others are too.

 

[TheShark1]

The A700 is a metal body, but it's smaller and has more aggressive venturi assist than the old metal case 2nd stages. Those two things definitely change the character of how it breathes. So it's not just like the old ones.

Sounds like an improvement?

 

[halocline]

Sounds like an improvement?

Oh, just when we were starting to get along so well....

Some people might think of it as an improvement. I wouldn't. It looks nicer in the showroom and likely has better WOB numbers on a test machine. Are you a test machine? If not, don't pay much attention to the WOB numbers.

But as I said, it will serve you well.

 

[buddhasummer]

For the interest of others reading...

Interesting results?

 

[Nemrod]

For the interest of others reading...

Interesting results?

 

[Nemrod]

The A700 has a smaller main diaphragm in order to reduce the size of the first stage, the G260 seems to be a full size regulator. Since I am not knowledgeable on the parts use for modern SP regs, I cannot say for sure but I assume they use a different diaphragm. Everything being equal, and in this case it pretty much is I bet, the reg with the full size housing will out perform the one that is smaller. More mechanical advantage and better Venturi development.

What is the case fault difference on these two models?

N

 

[Fossil_Diver]

Larger second stage diaphragms are usually more sensitive to pressure changes than smaller ones

 

[halocline]

More mechanical advantage and better Venturi development.

What is the case fault difference on these two models?

N

I think you're right about the mechanical advantage but not about the venturi assist. Smaller case=less volume=faster air flow through the case=more venturi, assuming everything else is the same.

I suspect case fault geometry is practically the same on the two, but I don't know for sure.

 

[redacted]

The venturi assist designs are very different. The G-xxx regs sort of leak some gas into the body and stick a vane in the mouthpiece to direct or interfere with the flow a bit. The barrel on the A700 has a fairly large opening pointed at the mouthpiece with a capability to block it much like the aspirator on a D-xxx but with a user control. I expect you could make that thing FF like crazy. For recreational diving with depth above 130 ft and RMV in the 10 to 20 liter range, I doubt if it makes much difference.

 

[halocline]

I was looking for a A700 schematic but I don't have one. For some reason I seem to remember that it uses the same poppet as the X650 which was sort of a strange replacement for the D series, so it doesn't surprise me that the aspirator is similar.