Reg setup... 2nd stage + octo or 2x 2nd stages?

[chadmeister]

Hahaha @Searcaigh

Well, xtx40 reg set with matching octo or xtx50 x2 regs? The overall package will cost me the same!!

 

[tbone1004]

Apeks second stages 101

ATX/XTX have all but identical internals. The only difference is the barrel has a machined port on both sides so it is reversible and a collar that rotates to allow for them to be switched. The exhaust ports are user changeable between narrow and wide *nice feature actually*, and the front cover is a bit different. So some minor case changes, but for all intents and purposes they are the same regulator. Reversing is a nice feature for stage/pony bottles depending on how you route them.

40's and 50's are identical except for the adjustment screw, this can be upgraded at a later time with no issues.
50/100/200 are identical except for chrome accents on the case.

All of this saves Apeks tremendous amounts of manufacturing costs by having a very small SKU list.

DS4 (50), DST (50), FST(100), FSR(200)
DS4, good for stages/deco bottles, fixed port routing
DST, great for backgas/sidemount. Swivel turret is nice, and the port on the bottom is nice. Also has two HP ports, DS4 only has 1
FST, useless, waste of money
FSR, nice because it has a replaceable hard crown inside, but this should only be an issue if your service tech screws up badly. Has fixed ports, and isn't worth the price premium.

Personally I would go for XTX50 with DST, unless the 40's are significantly cheaper.

Color is stupid, they are going to grab the one in your mouth, plan your hose routing accordingly. I.e. octo on a suicide strap/necklace, and plan for your primary to donate. Advantage of the XTX50's is that while slightly more complex which makes some people mad, the octopus can be turned all the way down when you aren't using it to prevent freeflows, and in the event of an OOA donation situation, you donate your primary which is ideal because it is known to be working and is the best breather, and then when you grab your octo which on your neck is good because you just look down and it's always right there, and then turn the knob and now it breathes just as well as your primary.

My recommendation for two pairs was to grab a XTX50/DST, and then another XTX50/DST if you have any interest in sidemount or backmount twinsets at all. It will save you equivalent of about $200 USD if you buy them together and as the first stage is the one with more common failures, you can always carry a spare first stage and just swap your hoses over if you have a failure... Best way to do this is just to buy a "doubles package".

 

[chadmeister]

Wow tbone1004 that was very informative! And extremely well written. I've read a lot of what you've written but you did it so eloquently I've felt I've learned it all for the first time!

As for the xtx50/DST + xtx50/DST that you call a double's package; I've went on my excel sheet with prices from lucasdivestore that I created and it can be bought for around 700€ if bought as configured above. If configured as a doubles package advertised on a website it would be 1150$ (with DS4 though) on DSIR...

 

[tbone1004]

that's a great deal from lucas, for 700euro I'd jump on that if you can grab 2x XTX50, and 2x DST's for that price. Keep in mind you'll need a few more hoses and an SPG, but that shouldn't be more than about 150E total for the inflator hose, correct length regulator hoses, HP hose, and SPG.

 

[eelnoraa]

The FIRST stage is overbalanced. As you state, it provides improved performance on deeper dives. ....

This is a marketing scheme to turn a design issue into a feature.

 

[chadmeister]

@tbone1004 pm me if you want the excel sheet I made with all the prices from Lucas, I can email it to you (all Apeks XTX40/50) and diff combos. All combos are cheaper to buy in the actual package presented except for one of them for some reason! It was the DS4+XTX40, they were 55€ cheaper to buy alone then combine than to buy them combined! And so buying DS4/XTX40/XTX40 was actually 71 € cheaper than buying a combo then adding on the XTX40.
What would correct length hoses be? And I'm thinking a simple brass w/glass SPG anyway for 53.3€ hehe

@eelnoraa can you elaborate?

 

[eelnoraa]

In a perfectly balanced 1st stage, the IP should be above the ambient pressure by a constant. So as depth increase, IP increase accordingly, but the difference is more or less fixed. The so call overbalanced 1st stage basically increase the difference between IP and ambiemt ad depth increase.

With balanced 2nd stages like all Apeks, a slight increase in IP-ambient pressure won't have any effect at all in breathing performance. So the overbalancing results in nothing. With unbalanced 2nd stage, the increase in IP-ambient pressure will only result in the increase of 2nd stage freeflow.

As to why some 1st stage is "overbalanced", it is NOT by design. It is the side effect of a design compromised. How do manufacture explain this compromised? By making it into a feature

 

[tbone1004]

to elaborate a bit further, the overbalancing can actually wreak havoc on very deep dives as the increase in IP will cause the regulators to start freeflowing at depth due to the downstream nature of the second stages. It is not uncommon for divers to simply remove the environmental seal if they are regularly going to 50+m of depth. This is also why you see many rebreathers using piston first stages or the Apeks US4's as the O2 solenoids and/or leaky valves are VERY sensitive to IP changes. I use Poseidon regulators and they have had to design around this issue as the semi-upstream nature of the Jetstream and Xstream actually cause the regulators to breathe harder with increased IP.

Regarding pricing, you can email me if you want, but frankly I'd grab the XTX50/DST if you can for not much more than the DS4/XTX40. You'll be much happier in the long run.

Regarding hoses. See below videos. I like to run my single tank setups for wetsuit diving identical to the left post of a doubles setup. Below is done with a Scubapro MK25, but same routing as an Apeks DST. I then put the primary regulator just behind the inflator hose on the turret, and personally run a 40" hose with a ball swivel. You can also run a 7' hose in a Hog loop. This allows easy transitioning between singles and doubles, has all hoses going where they belong, and allows the most streamlined setup. Lengths are 36/40/84 inches for the primary depending on how big you are and whether you go with a "short" hose *note 36" is standard octopus length, 40" is standard stage/deco bottle, and 84" is standard long hose*.
Octopus is 22", nice and short since it doesn't have far to go.
Inflator will depend on your BC, but 22" is standard BP/W length from Halcyon, Deep Sea Supply, etc. Many/most bc's will come with an appropriate length inflator hose though.
SPG is typically 26" for clipping to your left hip D-ring

View attachment 215336

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[video=youtube;2OrTXi-hjv4]https://www.youtube.com/watch?v=2OrTXi-hjv4[/video]
[video=youtube;BuvOOtolVZc]https://www.youtube.com/watch?v=BuvOOtolVZc[/video]
[video=youtube;dSKGKG-8zRA]https://www.youtube.com/watch?v=dSKGKG-8zRA[/video]

 

[chadmeister]

Thank you both! And @tbone1004 nice touch with the vids [emoji16]

I'm a little surprised no one is using the Octo/inflators that come on the BC, like the TUSA IR3 for example... None of you use them? It would seem more streamlined and somewhat eliminate the need for the necklace.

I'd like to know what you super knowledgeable mates think

 

[kwinter]

Most of the octo inflator combos breathe like crap and are difficult to use. You are breathing from a very short corrugated hose and trying to maintain buoyancy of your wing at the same time. That being said, I have used one on my rebreather to give me access to my onboard cylinder in a bailout situation. That is just about the only justification I can provide.