Your favourite second stage and *why?

[Geo7]

In terms of freezing resistance in extremely cold water, the Mares Abyss is better than other regulators (even the Conshelf), since the external bypass allows the air to expand downstream of the moving lever parts, so the cold is generated further down. Only the Jetstream/Xstream beats it in freezing resistance, and by a good margin (again, air expands far from moving parts). This is what I understood from the US Navy tests. I think the Scubapro 156, and Conshelf are plenty resistant to freezing for most of us though.

(When I used to do cold water diving (european lakes), even plastic regs with a metal tube had been fine. And now in SoCal I only care about resistance to salt and sand.)

 

[Nemrod]

I can't comment on the exhaust side. I've never really thought about it until Nemrod's comments.

The exhaust side is only the other half of the breathing cycle and some have said the more important half . Kinda of like dropping an intake manifold and 4 barrel on a V8 and then choking the engine with a single exhaust, does not work so good. I do not know about you guys, but I still got a V8 under the hood . I cannot get it in until I get it out!

 

[Bigbella]

Only the Jetstream/Xstream beats it in freezing resistance, and by a good margin (again, air expands far from moving parts). This is what I understood from the US Navy tests. I think the Scubapro 156, and Conshelf are plenty resistant to freezing for most of us though.

I did most of my crazier ice diving and / or near-freezing diving, using Cyklon 300s (fitted with either vodka or glycerin/alcohol-filled rubber or metal antifreeze caps, seen below), well before the release of the Xstream -- maybe even the Jetstream / Odin (then marketed, for some odd reason, as the "Cyklon Maximum," around 1980); or, at least, I had yet to see one in the water.

The Cyklon was dynamite under frigid conditions and I never experienced any free-flows; they also took a load of punishment (we were all oaves back then) -- and they really flew in the face of that "lower the IP for cold water" rationale, since the 300 specified a maximum IP of 12.5 bar (181 psi and change), and none of us thought to lower it . . .

 

[rhwestfall]

`I love my Xstreams... They are quite different from any other reg I use. They are my technical cold water regs. They really are so different....

 

[Bigbella]

`I love my Xstreams... They are quite different from any other reg I use. They are my technical cold water regs. They really are so different....

Yes, they are quite nice.

I have Mk3 first stages attached to my full-face masks as well as often using Xstream second stages as octopuses; but my most common set-up, nowadays, is the Mk3 with Jetstreams (whose guts are nearly identical to the smaller Xstream regulators -- and the shorter of those two valves seen below) . . .

 

[JP_SCUBA]

I'll just jump in here with a quick question. Does anyone know if the adjustable orifice/volcano for a Zeagle second stage or Oceanic second stage will fit a Scubapro 109 second stage? They look fairly similar but I don't have one to compare and can't find any dimensions on them. Are the threads 5/16"-32 or something different? Attached picture of an Oceanic one. TIA .... JP ....

 

[brsnow]

1.) Atomic Z2, wide exhaust excellent breathing
2.) c370 light and smooth

 

[Open Ocean Diver]

T3 - automatic Venturi adjust, automatic seat saver, big exhaust, Micro adjust, light, full cover purge, soft comfortable mouthpiece, titanium barreL, lever and orifice, OEM titanium swivel LP hose. tough nylon reinforced case… breath light and looks good.

 

[Kupu]

I'll just jump in here with a quick question. Does anyone know if the adjustable orifice/volcano for a Zeagle second stage or Oceanic second stage will fit a Scubapro 109 second stage? They look fairly similar but I don't have one to compare and can't find any dimensions on them. Are the threads 5/16"-32 or something different? Attached picture of an Oceanic one. TIA .... JP ....

James79 recently reminded me about parts from thescubamuseum, SP reproduction orifices are currently available f you are looking for replacements and don't care if they are OEM.

 

[halocline]

Maybe my favorite 2nd stage in terms of what is the most interesting and highest performing 2nd stage I personally have used would be the SP pilot. I'm also a huge fan of the D series regulators that were sort of descendants of the pilot; not directly but via the air1. I have many D300s and they are excellent breathers.

But what I end up using most of the time is the SP balanced/adjustable or 109 converted to balanced. So maybe that's my favorite, because its such a great day in/day out workhorse.