Mixing 1st and 2nd stage brands

[mostlyirish]

Is there any reason I should not mix a Scubapro MK21 1st stage with another brand (Apeks for example) 2nd stage?

 

[flyboy08]

Nope.

 

[lowwall]

Nope.

*Except there are a relatively small number of second stages that have a different intermediate pressure specification so would require an adjustment on the first stage. Notable examples include Poseidon Cyklon and all Mares seconds.

 

[broncobowsher]

Go ahead and mix. Even the outliers are generally fine. My not be perfect optimal tuned, but should be acceptable. If something is wrong it will be generally a leaker (more IP than the 2nd wants and that can generally be adjusted out).

Really common to be on a trip and someone has an issue with a reg and a spare 2nd stage is screwed on to fix it.

 

[elan]

Should be a non issue in that combo. I run Zeagle ZX (apeks clone) on SP MK5 and MK25 with no problems.

 

[BoltSnap]

It is generally OK as long as the IP matches. The issue comes when it is time to do the service which maybe a pain if one service center can service one brand but not the other. I prefer to use matching first and second stage brands including octo. just to avoid the servicing issues that comes up.

 

[whaylonsmithers]

BoltSnap is right about servicing being the main consideration. Either DIY it or make sure you have someone happy to work on both brands in a single reg set.

Most 1st/2nd combinations will be quite tolerant of each other and plenty of people do it. My old MK21 repair procedure says the IP range is "9-10 bar (130-145 psi)". Meanwhile the (2009) Tx50 manual lists the staggeringly different 1st stage IP range of......"130-145 psi (9-10 bar)." That suggests a Tx50 2nd would be right at home on a MK21 but the SP compatibility chart doesn't show it, so of course you wouldn't do it.

Finally, warranty? I don't a clue about this, but if the 1st/2nd are different brands I speculate you may find warranty claims a little bit tricky.

 

[BoltSnap]

My old MK21

How do you like your MK21 first stage? What second stage do you use with it?

 

[whaylonsmithers]

How do you like your MK21 first stage? What second stage do you use with it?

Sorry, I've got an old manual but not an actual MK21. I expect it would be a good reg, but I can't find much to like appearance wise.