I am getting back into diving and my dilemma is choosing between two regs. Atomic Z2X or Scubapro MK25/S600. I have found them for 499 & 515. LDS says S600 has a plastic piston in second stage that has been known to fail. The reviews do this model great justice. Thanks for any feedback
Confused on two regulators
- Thread starter rustyrun
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Hello rustyrun,
Can't speak directly for the Atomic, but as to the Scubapro S600 the plastic poppet in the second stage is used in many of their balanced regulators. I have serviced many, own a few myself and have never had an issue with the poppet failing. There were some issues with older style poppets years ago and some of those are still around in used regs, but as far as new production regs I wouldn't hesitate for a second in buying a SP reg.
Can't speak directly for the Atomic, but as to the Scubapro S600 the plastic poppet in the second stage is used in many of their balanced regulators. I have serviced many, own a few myself and have never had an issue with the poppet failing. There were some issues with older style poppets years ago and some of those are still around in used regs, but as far as new production regs I wouldn't hesitate for a second in buying a SP reg.
I've had my MK25/S600 combo since '03 and never had any issues.
halocline
Contributor
There's no piston in the 2nd stage; there's a poppet and a balance chamber, plus a 2nd balance chamber. It's a little complicated , but actually very similar to the atomic 2nd stages IIRC. In the MK25 1st stage, the piston has some plastic; that's different from all the prior scubapro piston 1st stages. The MK25 composite piston works fantastic, but it does have a tiny o-ring that can on occasion leak, and I believe the fix for that is replacement of the whole piston assembly. That would be a warranty item, I would think.
Interestingly, someone recently posted a message that says that scubapro is switching to a metal air barrel for the S600; currently it's plastic. This should be an improvement, as the metal air barrel will warm and moisten the air a bit. So, if you're buying a S600, get one with the metal barrel or at least get the dealer to agree to replace the plastic barrel with the new metal one when it comes out.
Overall, the MK25/S600 should be very similar to the atomic; atomic was founded by ex-scubapro engineers, who more-or-less based their design on the MK25/S600, with some refinements. One nice thing about the atomic is that you can get the first stage packed with Christolube, which makes it quite freeze resistant and keeps the ambient chamber really clean. The downside is that you need to replace the Christolube at every service, and that stuff is not cheap. One thing I don;t like about atomic is the seat-saver in the 2nd stage which, apparently, keeps the seat completely off the orifice when the reg is not pressurized. This means you can't soak the reg unless it's connected to a tank. That would be a deal breaker for me, but others don't seem to mind it. I don;t know if the model you're looking at has that feature.
Either way you're getting a very high end reg set.
Interestingly, someone recently posted a message that says that scubapro is switching to a metal air barrel for the S600; currently it's plastic. This should be an improvement, as the metal air barrel will warm and moisten the air a bit. So, if you're buying a S600, get one with the metal barrel or at least get the dealer to agree to replace the plastic barrel with the new metal one when it comes out.
Overall, the MK25/S600 should be very similar to the atomic; atomic was founded by ex-scubapro engineers, who more-or-less based their design on the MK25/S600, with some refinements. One nice thing about the atomic is that you can get the first stage packed with Christolube, which makes it quite freeze resistant and keeps the ambient chamber really clean. The downside is that you need to replace the Christolube at every service, and that stuff is not cheap. One thing I don;t like about atomic is the seat-saver in the 2nd stage which, apparently, keeps the seat completely off the orifice when the reg is not pressurized. This means you can't soak the reg unless it's connected to a tank. That would be a deal breaker for me, but others don't seem to mind it. I don;t know if the model you're looking at has that feature.
Either way you're getting a very high end reg set.
Hatul
Contributor
I have the Atomic ST1 which is functionally similar to the Z2X The issues with this are:
1. the 2nd stage seat saver makes soaking a little problematic,
2. the reg breathes well at depth but the cracking pressure is a little rough in shallow water, and
3. it has no pre dive switch to increase the cracking pressure. If you remove the reg from your mouth underwater you can get some big time freeflows. The knob has only a small effect on the cracking pressure.
Adam
1. the 2nd stage seat saver makes soaking a little problematic,
2. the reg breathes well at depth but the cracking pressure is a little rough in shallow water, and
3. it has no pre dive switch to increase the cracking pressure. If you remove the reg from your mouth underwater you can get some big time freeflows. The knob has only a small effect on the cracking pressure.
Adam
The S600 is being switched over to a metal air barrel. This is an inline change: there will not be a warranty upgrade for plastic-barrel versions. If you get one with a plastic barrel and want it upgraded then you will have to pay the cost for the parts. There currently is no performance or safety issue with the plastic barrel, so no warranty replacement is deemed necessary. The S600's should be shipping with metal barrels as of this point, IIRC.
Scared Silly
Contributor
FWIW, the inlet tube (air barrel) for the Atomic is brass (Z2 or M1) or titanium for the others. The popet for Atomic is also nylon/plastic. As for soaking the Atomics when they are not pressurized, you just want to the first stage above the second. I prefer the Atomics over the ScubaPro mostly because I think the second stages have a cleaner and smaller profile. ScubaPRo second stages always seem clunky to me.
Never heard of issues with the composite pistons on the MK25. The only time you will have a problem with the piston is if the technician uses a metal pick to remove the o-rings. The technician should take that pick and stab himself in the eye, for being that careless.
The new S600 have the metal air barrel. If you get a S600 that looks just like the one in the link, you will have the metal air barrel.
S600 - SCUBAPRO-UWATEC
You will be satisfied with either brand. Get the reg you like the best.
The new S600 have the metal air barrel. If you get a S600 that looks just like the one in the link, you will have the metal air barrel.
S600 - SCUBAPRO-UWATEC
You will be satisfied with either brand. Get the reg you like the best.
Downing
Contributor
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