Scubapro 156

[Kupu]

How does the 156, BA150, and the 109 compare to the beloved g250?

............................ Weight <> Inhalation <> Exhalation <> Vacuum Assist
............................................. <> Resistance <> Resistance <> (VIVA)
-------------------------------------------------------------------------------------------
G250.................... 8.75 oz <> 1.2" - 2.0" <> .4" <> Adjustable
156 B/A.................12 oz <> 1.2" - 2.0" <> .4" <> Moderate
150 B/A.................12 oz <> 1.2" - 2.0" <> .6" <> Moderate
109 Adj.................12.5 oz <> 1.2" - 3.0" <> .6" <> Moderate

Collective experience & catalog specs reveal the main difference in performance is related to the exhaust valve (about 40% larger) used in the G250 and 156 Balanced Adjustable. Whether or not the reduced exhalation numbers matter depends on the type of diving and individual sensitivity to exhalation pressure. In the past I did not notice or care about the difference, now I do notice.

So the G250 and 156 B/A have some performance advantage on the exhalation numbers over 150 B/A and 109. Throwing a new regulator in with the vintage, my current order of preference for local diving is G260, 156 B/A, G250, 150 B/A, then 109.
If I want to show off some old school style to match my greying hair while on vacation, the 156 B/A paired with MK5 or MK10 is tops.

Compared to the integrated tee and solid cover of G250, the pop off rubber exhaust tees and flexible diaphragm covers of the SP metal second stages are a weakness. They wear out over time and are getting harder to find, and unless someone could print one it would be about impossible to source a replacement tee for 156 B/A.

As mentioned by Halocline, getting optimal tune on the metal second stages can sometimes be challenging. Like the G250s, most Balanced Adjustables can be sorted out nicely without much trouble, but performance of the 109's can be quite variable. I'm sure part of that is just my patience and skill level, but I also think that variable performance increases the farther one goes back on B/A & 109 production dates. Partly due to simply being older and more used, but also perhaps because of differences in batches and tolerances during the 16 years SP sold 109s (1969-1985).

 

[thbcthomas]

Thanks again @Kupu for all the info.

 

[Nemrod]

The original G250 is the better second stage. The 109 has an actually quite restrictive exhaust valve and tee, the 109/156 is more negative in the water and the Venturi is less effective. The glass fiber polymer case of the G250 can shrug off hits that would leave a 109/156 quite sad and dented.

Here is a 109 with the 26mm exhaust that was used through the 156 BA model. Only the CE 156 BA has the larger 30mm exhaust valve. Can I tell the difference in use between a 109 and a CE 156 and a G250, yes, especially as I have gotten older, yes.



Note also the different clocking of the spider supports on the CE 156. The G250 exhaust tee is less restrictive than the rubber slip on tee of the 109/156, even with the larger valve the CE 156 is not quite equal to the G250 in my experience.

I set, for my use, any adjustable regulator such that with the knob fully out the regulator will very slightly leak. This way, when I am swimming hard into a current and my 70 yo lungs are just not feeling it, I can turn the knob out and there is no cracking effort, just the reassuring rush of air from the powerful G250 Venturi . That makes me very happy. Because Deep Down:

 

[Geo7]

Does that mean that some 156 were CE stamped and that is the only difference?

I had a CE 156, which looked like yours. But there is also a version with the plastic sleeve for the lever. I think @Open Ocean Diver has one...

 

[Nemrod]

Does that mean that some 156 were CE stamped and that is the only difference?

I had a CE 156, which looked like yours. But there is also a version with the plastic sleeve for the lever. I think @Open Ocean Diver has one...

I do not know every variation of the CE 156 BA second stage. However, a 156 BA is not the same as a CE stamped 156 BA. The CE stamped 156 was given the larger 30mm exhaust valve so as to pass the standard, some supposition on my part here, that the 109/156 with the 26mm valve did not. Thus the inclusion of the larger 30mm valve. The plastic sleeve, yes, I have seen that, again, just a guess, my CE 156 BA is earlier version and the plastic sleeve was on the last version. Really, I do not know. But I do know that the 30mm exhaust valve of the G250 and CE 156 BA makes a difference in use for me.

Back when the 109 was introduced by Scubapro I was working part time at a store that had Scubapro, Dacor and some US Divers. My boss handed me a brand new 109, gave it to me (I was still using a 1966 small valve two screw 1085), and said to use this in classes because he wanted to go all Scubapro. I tried a new US Divers 1085 which had years earlier gotten an exhaust valve size upgrade of significance and at that time it was my opinion that I preferred the 1085 and did so for decades leaving me to this day with a NIB 109, well, okay, it has been in a pool a few times .

 

[Kupu]

However, a 156 BA is not the same as a CE stamped 156 BA. However, a 156 BA is not the same as a CE stamped 156 BA. The CE stamped 156 was given the larger 30mm exhaust valve so as to pass the standard, some supposition on my part here, that the 109/156 with the 26mm valve did not.

With respect, I disagree with the reference to existence of a 156 with 26mm exhaust valve and think all 156 were created equal if we are talking about the 30mm exhaust valve, regardless of whether or not they are CE stamped. The lack of CE stamp on a few 156 may be related to production/sales region or they may simply be early production 156 versions. I believe a Balanced Adjustable is simply not a 156 version unless it has this 30mm exhaust valve, if it has 26mm exhaust valve it is the earlier 150 version.

One example of 156 without CE stamp is shown in post #15 in this thread, @Jacobyz may have one as well.

Does that mean that some 156 were CE stamped and that is the only difference?

I had a CE 156, which looked like yours. But there is also a version with the plastic sleeve for the lever. I think @Open Ocean Diver has one...

There is some info on 156 variations in this thread.

 

[Nemrod]

With respect, I disagree with the reference to existence of a 156 with 26mm exhaust valve and think all 156 were created equal if we are talking about the 30mm exhaust valve, regardless of whether or not they are CE stamped. The lack of CE stamp on a few 156 may be related to production/sales region or they may simply be early production 156 versions. I believe a Balanced Adjustable is simply not a 156 version unless it has this 30mm exhaust valve, if it has 26mm exhaust valve it is the earlier 150 version.

One example of 156 without CE stamp is shown in post #15 in this thread, @Jacobyz may have one as well.


There is some info on 156 variations in this thread.

I imagine you are correct. Thanks. The only 156 second stages I have held that had a 30mm exhaust valve were also CE stamped, in other words, being in the shop and picking them up out of the box new. I have never seen a 156 that was not CE stamped save for the one in the referenced photo. If a few escaped early on without a CE marking maybe there was a transitional period after the larger valve was provided but before CE was granted. Who knows. That being the case, the only way to know for sure if it is a 156 is to pull the tee off or pop the purge cover off and look at the valve and spider. Darn then, I may have passed up a deal on one that was not CE but was claimed to be a 156! Thanks again, now I could kick myself!

Edit to add, I just looked at both my 156. They are CE stamped. The tee is different, something I had forgotten about. Both of my 156 have a plastic tee whereas my 109 set has a softer rubber tee. Looking up inside the tee the 156 has a vertical divider in the center above the exhaust manifold bell, the 109 does not. The chin pad area is differently shaped as well. From shop days, do not remove or install that tee without getting it nice and warm.

And with all the exhaust valve talk, here is a G250 look see:

 

[Open Ocean Diver]

Does that mean that some 156 were CE stamped and that is the only difference?

I had a CE 156, which looked like yours. But there is also a version with the plastic sleeve for the lever. I think @Open Ocean Diver has one...

Brand new right out of the box. Strange serial number.

 

[Kupu]

I may have passed up a deal on one that was not CE but was claimed to be a 156! Thanks again, now I could kick myself!

For years I have been in the habit of scanning for sale listings & auction sites looking for elusive 156's and usually can filter out the incorrect listings. As you already know, most Balanced Adjustables described with 156 tag are not actually.

At the moment there is CE 156 with MK20 listed on Japan's JDirectItems with 1-2 bidding days left, current asking price is about $170.
I might try for it if the second stage was in great shape, but passing since the second stage has some minor wear and I don't really need another.

 

[Umuntu]

Were there any late 108s with a 30mm exhaust valve ?