Reg help

[padi1029]

Just got my regs back from LDS after annual service and come to find out the housing on my 2nd stage is cracked, cannot be replaced because my set up is over 12 years old and Oceanic no longer makes the part. So, guess it's time for some new gear. My Oceanic rig served me well and owes me nothing, but it seems like service for Oceanic in Northeast US is hard to find, and parts become obsolete quickly and are not always easy to get.
I have been reading many articles and speaking with my LDS and all seem to have the same conclusion, Aqualung, Apeks or Scubapro are my best choices. The Apeks and AL are attractive right now because of the free octo program AL is running, and my LDS is an AL dealer so service is easy, and AL's free service parts warranty is another plus.

Can anyone make any recommendations or share their experiences with the AL Legend series of regulators, or the APeks XTX or ATX series. What is the difference between Apeks XTX & ATX? My diving will be mostly warm water, with possiblly a few cold water (NJ east coast) dives.

In " Modern Regulators for Dummies" terms, can someone please explain the difference between a venturi adjustment switch and the resistance control knob, and if I need one over the other (Note, I am a a large person, 601, 212 lbs, physically fit but a heavy breather).

Thanks

 

[chrispete]

The venturi assist basically creates a low pressure area in front of the diaphram which helps to keep the valve open with less inhalation force required to keep it open (i.e. once the air starts flowing it keeps flowing easier) The resistance control actually changes the force of the spring holding the LP seat to the crown (i.e. makes it easier or harder to "crack" the valve and start the air flowing in the first place)

 

[redacted]

PM cerich (http://www.scubaboard.com/member.php?u=40249) and see if he can help. A 12 year old regulator should not be obsolete. Most of the regs I dive are twice that age. It's pretty hard to kill a metal case and Scubapro's design philosophy means parts for their modern regs will also work in many of their 30 year old models.

Venturi adjustment places a physical obstruction on the pathe of the air flowing from the 2nd stage into your mouth. It is useful in controlling freeflow and in reducing the feeling of positive pressure breathing (gas being forced into your lungs).

Resistance control knob adjusts the pressure of the LP seat against the orifice which controls how much effort it take to start gas flowing when you inhale. Most modern regs can get this force down to about .6 inches of water, but it may not be very stable at that setting. Good regs operate fairly well aroud 1 to 1.2 inch. With a resistance control knob, cracking pressure can be set more aggressively for easiest breathing and adjusted for stability or other conditions by the user as need.

For designs that will accomodate both, there is little reason (other than a little extra price) not to have those features. Some high performance regs work quite well without them though.

 

[WarmWaterDiver]

There are some decent animated sequences on the Scubapro UK site that illustrate this - and can be viewed for the fundamentals of these things when present on a balanced second stage design (whether Scubapro brand or not). They do have a bit of text in them about what they think sets Scubapro apart from the competition though.

http://www.scubapro.co.uk/utilities.asp#util8

Scroll down until you see

"Animated demonstrations of Scubapro Regulators - Second Stage"

 

[DA Aquamaster]

I am pretty heavily biased toward Scubapro based on 21 years of diving experience with them.

But I am pretty impressed with the Aqualung Legend LX. The second stage's poppet (shuttle valve) is an interesting mix of old and new Scubapro technology using a light plastic one piece poppet (similar in concept to Scubapro's newest one piece S-Wing poppet) that is shaped much like Scubapro's older two piece balanced poppet design. Performance of the LX second stage is generally similar to a G250.

The Legend first stage is well constructed and the quality is good.