Apeks First Stage Technical Questions

[DMJohn]

Last week I picked up new set of Apeks regs at the dive shop I DM for. Not sure what happened but somewhere over time apparently someone swapped some parts at the shop and what I ultimately have is an ATX40 first stage (yoke) with an XTX50 second. I didn't realize they were mis-matched models but knew there had been some swapping because the box originally indicated DIN. I also chose this set because of the first stage's simpler design (no center swivel).

My main question is what, if any, performance differences are there between the ATX40 first stage and the XTX50 first stage? Are there any internal advantages to one vs the other?


I have the option to swap for a matched set of XTX50 first/second but if there is no performance or quality difference I may stick with the current set I have (ATX40 first / XTX50 second).

One other consideration, I plan on taking some tec diving classes soon and is there an advantage for using one vs the other in tec diving (other than 2 HP ports on the 50)?


Any insight and help would be greatly appreciated. Thanks!


John

 

[azchipka]

The two high pressure ports on the XTX 50 won't make any difference on you Tec course, as you only really need a single HP port on the left post in a down facing position. The only difference between the 40 and 50 second stage is the 50 has an adjustment knob for cracking pressure and the 40 doesn't.

As far as the 1st stage there is no such thing as a XTX40 or XTX50 1st stage. Heres a decent page that shows the First Stage Models. If you can tell me which one you have I can tell you the difference between them. Apeks Regulators at Go-Dive

 

[herman]

To answer your basic question, no, there is no performance differenance between the first stages.

 

[buddhasummer]

ATX40, no cracking pressure knob, is usually sold with a DS4 1st stage, sealed/fixed/4MP/1HP

XTX50, cracking pressure knob, is usually sold with either DS4 or DST 1st stage sealed/swivel/4MP/2HP

 

[DMJohn]

The two high pressure ports on the XTX 50 won't make any difference on you Tec course, as you only really need a single HP port on the left post in a down facing position. The only difference between the 40 and 50 second stage is the 50 has an adjustment knob for cracking pressure and the 40 doesn't.

As far as the 1st stage there is no such thing as a XTX40 or XTX50 1st stage. Heres a decent page that shows the First Stage Models. If you can tell me which one you have I can tell you the difference between them. Apeks Regulators at Go-Dive

Thanks for the response. I got the number ATX40 when I went to register the first stage SN online.

Here are pics of the regs I have:







Larger pics here:

http://www.motorcyclesportrider.com/scuba/apeks1.jpg

http://www.motorcyclesportrider.com/scuba/apeks2.jpg

http://www.motorcyclesportrider.com/scuba/apeks3.jpg

 

[Kern]

Thanks for the response. I got the number ATX40 when I went to register the first stage SN online.

The 1st stage is a DS4, the 2nd stage looks like an XTX 50.

Apart from external cosmetics, the XTX 50/100/200 2nd stages are the same.

 

[Fishpie]

There are a couple of possible advantages to the DST 1st stage.
1. The swivel makes it a better stage reg than the DS4.
2. It can be fitted with the 5th port (at extra expense) if you like the "Scubapro" style of hose routing.

The US4 has been a mainstay of back mounted doubles for many many years....good performance and as rugged and reliable as you can get.
As everybody else has pointed out there is no difference in the gas flow performance between any of the 2nd stages....from the cover pic yours looks to be the latest XTX generation.

 

[buddhasummer]

The 1st stage is a DS4, the 2nd stage looks like an XTX 50.

Apart from external cosmetics, the XTX 50/100/200 2nd stages are the same.

Kern is correct on all counts.

 

[DMJohn]

Thanks for all the feedback. I think I'll keep what I have since I got a great deal on it. I'll post up after I get a chance to use them and see how it goes.

 

[buddhasummer]

Thanks for all the feedback. I think I'll keep what I have since I got a great deal on it. I'll post up after I get a chance to use them and see how it goes.

Thats what Id do too. You will be fine. I use a DS4/ATX40 on one of my rigs and FSR/XTX50 on another both use same 1st and 2nd stage service kits. I cannot tell the difference when breathing of either. Have fun.