Opinions

[tbone1004]

@Protondecay123 my primary regulator setup for backmount doubles, CCR, and sidemount is a Poseidon Jetstream on a Scubapro MK25. No issues. They can be tuned to behave at the 135-145psi IP that most regs call for, but it's better to pull the first stage back down to the 123psi.

@Kharon IP that changes with depth is absolute intermediate pressure, second stages only care about relative intermediate pressure. All downstream second stages that are put on an over-compensating first stage *basically all sealed diaphragms*, will eventually start freeflowing as you get deep enough because the relative IP climbs with depth. Poseidon first stages are all open, and all piston first stages whether sealed or not will hold a constant relative IP. The Jetstream/Xstream will get a bit stiffer to crack on an over-compensating first stage, but it will stay well within the tolerances of any CE approved regulator.

 

[Caveeagle]

Those were some of the issues I was curious about the potential setup with having a non-Poseidon 1st Stage. (Frankenregulator)

FWIW, It’s sherwood and Dive Rite have sold versions of their regulators with re-branded Jetstream second stages. So, there is some history of mating this second stage with non Poseidon first stages.

 

[rhwestfall]

My modern regulators are Poseidon XStream and ScubaPro MK17/G250v. Wife and daughter dive HOG D1/Classics for cold water. Little to no issues at all.

 

[tbone1004]

FWIW, It’s sherwood and Dive Rite have sold versions of their regulators with re-branded Jetstream second stages. So, there is some history of mating this second stage with non Poseidon first stages.

Dive Rite paired it with a Poseidon MK3 first stage, don't believe they ever paired it with anything else. Sherwood sold it with both their first stages and Poseidon first stages.

 

[guyharrisonphoto]

Kharon, you just cannot go wrong with Poseidons. I have 2 regs: a Kraken, and an Poseidon Xtream (first and second stages). I fully believe that you will never have any problems with these. The first stage is built like a rock and designed not to wear out. the second, if it anything like my Tekna servo seconds in the 80s, will go many many years without really needing a service, if you are so inclined. Breathing--second to none. Like tbone, I am a big fan of this design.

 

[howiebrou]

Can you mix and match poseidon 1st and 2nd stages? i.e. are the 1st stages for the Cyklon the same as for the jet stream or xstream?