Collectors list of notably easy breathing second stages?

[rsingler]

It would be great to find more regulators offering exhalation that feels effortless.

Kraken double hose.

Home | Vintage Double Hose

 

[Fibonacci]

Kraken double hose.

Home | Vintage Double Hose

Recent production, yes...

 

[Kupu]

I eyeball the Kraken from time to time, and sooner or later will get a double hose or 3 to noodle around with. Need another job, or maybe stop feeding the pets for a while, to save some money and support my habit. Looking at vintage double hose regulators recently, and could not resist making a couple low bids on beat up RAMs while searching for a Voit Navy that might be of interest to Fibonacci. Purchased 4 used tanks yesterday... a day after telling my lovely wife that I have maxed out the scuba gear budget for a while. Even though she prefers new stuff to my funny looking old gear (no matter how well it performs), at least she understands the habit.

Another update from Peter Katz regarding the Command Air design process to reach a consistent 0.5" cracking effort:

"During the development of Command Air we conducted hundreds of tests, varying the angles and curvature of the lever, its length and leverage ratio.
Also the shape of orifice and spring tension. We also changed the size of holes and their position on Sleeve and Boost knob.
The final result of the performance of this regulator is therefore a combination of many attempts and changes throughout the development.
So I can't say which part was decisive or more important."​

I had another read thru the 2011 Sea Hornet thread. Thinking a good deal will pop up sooner or later on the Pro Sub or Parkway versions here.

 

[Kupu]

I picked up a couple additions for the collection recently. First, a Parkway Nova, design similar to or same as the Command Air. Need to service it, but excited to open it up and hopefully get it rebuilt and in the water for a test drive. Curiosity about servo valve designs led me to pick up an Oceanic Omega II and after a few minor tweaks it is ready to dive. Really excited about the Omega, playing around with it at the work desk it breathes perhaps better than the AIR1.

After years of using the same regulator setup, I am having tons of fun building up the collection, seeing how they tick, and then diving the regulators.

 

[reefrat]

I picked up a couple additions for the collection recently. First, a Parkway Nova, design similar to or same as the Command Air. Need to service it, but excited to open it up and hopefully get it rebuilt and in the water for a test drive. Curiosity about servo valve designs led me to pick up an Oceanic Omega II and after a few minor tweaks it is ready to dive. Really excited about the Omega, playing around with it at the work desk it breathes perhaps better than the AIR1.

After years of using the same regulator setup, I am having tons of fun building up the collection, seeing how they tick, and then diving the regulators.

Lots of people loved their Omega 2's but I personally found them to be a very wet (disturbingly wet) breather!

 

[Kupu]

Lots of people loved their Omega 2's but I personally found them to be a very wet (disturbingly wet) breather!

I saw that a majority said the Omega II breathed on the wet side, seems like some had the issue more than others?. Just have to get this one in the water and see how it goes, the regulator passes a vacuum test on the surface. Some reports of being able to reduce the wetness by new diaphragm or exhaust valve, did you happen to try new parts? Hoping I don't feel like a manta in feeding mode when using it...

I would really like to try the Hollis 500se or even Omega 3, but I am not seeing them on the used market and in my price range yet.

 

[Kupu]

2 dives with the Omega II today, paired with a well tuned Deep6 second stage for comparison. I consider the Deep6 an excellent regulator, breathing on par with our newer high end scubapro second stages.

The Omega II certainly belongs on the collectors list from the standpoint of exceptionally easy inhalation and exhalation. It is stable cracking at .3 or less, inhalation is very smooth and easy. After using the Omega and then switching to the Deep6, the difference in exhalation was very noticeable, creating the feeling of having to push a breath out thru the Deep6 vs a very natural and effortless exhalation thru the Omega.

But...I certainly experienced the wet breathing. Not horrible, but it was a semi constant issue. Easy enough to clear the water out, but it kept returning. I have a new exhaust valve to install, but not getting to hopeful it will make the difference needed to make me want to use the Omega II on a regular basis.

On the topic of comparing regulators, I used the D350 with the Deep6 last time out. The D350 wins on all counts but one. The noise created by the D350 on inhalation was quite loud compared to the Deep6, to the point that I switched to the Deep6 for most of the dive despite the fact that the D350 breathed a bit easier.

 

[reefrat]

Two regs I always wanted to try but never did were the D350 and the Jetstream!

I'm guessing that the D6 is quite similar to a Hog second stage breathing wise, only thing I would like to see different on those two is an exhaust tee that puts the bubbles further out or back.
Also keep your eyes open for one of the late model SP Balanced Adjustable's - the European version with the G250 sized exhaust valve. I reckon one of those tuned so that the cracking pressure knob turned all the way allowed a slight trickle of bubbles would be an awesome second stage.

 

[Kupu]

I had forgotten about the European B/A, would buy one if I got lucky and could find it at reasonable price. Mark X Dual Balanced.
My trusty B/A and 109 set are past due for a rebuild, need to get that done so they can be compared with all the new/old stuff I am playing around with.

The relative noisiness of the D350 was unexpected, not sure I would have noticed it if diving that second stage alone and not comparing with another on the same dive.

 

[EdTeach]

There are many high performance second stages available, making it easy to obtain a regulator with very good to excellent breathing attributes. My current collectors fixation is to find models current or past, regardless of availability, that could be considered as above and beyond for excellent breathing performance. In example, second stages that are able to perform better than Scubapro G250 or equivalent.

The current list is as follows. Anyone have comments, corrections, or additions?

• Scubapro Pilot (unconverted). Can be tuned to inhalation effort .4" (or less?), exhalation effort lower than average. Parts not readily available, DIY effort high.

• Sea Hornet Commander & Command Air. Can be tuned to inhalation effort .5". Commander slightly better performance vs Command Air. Exhalation effort average? Parts not readily available, DIY effort medium. Also available under ProSub and Parkway brand.

• Scubapro A.I.R.1 (and converted Pilot). Can be tuned to inhalation effort .6" (or less?), exhalation effort lower than average. Parts not readily available, DIY effort medium-high.

• Scubapro D series (D400 - D350 - D300). Can be tuned to inhalation effort .6" (or less?), exhalation effort lower than average. Generally equal performance across the D series, except later D400 models with plastic orifice slightly less. Parts not readily available but easier to find vs Pilot/AIR1. DIY effort medium-high. Parts and kits no longer produced, but can be found with a bit of patience.

• Kirby Morgan Superflow. Can be tuned to inhalation effort slightly less than .8". Not sure if this one really belongs here, thinking it is on par with several current high performance second stages. Added as space filler. DIY effort medium. Parts and kits available with some effort required to source?

I have Pilots, Air 1's and all the D-Series SP regulators, as well as 109's, 156's and a G250. The Pilot is incomparable in my experience, though I have never used Sea Hornet or Kirby Morgan regulators. A properly set up Pilot is nearly effortless on inhalation. The Air 1 is a fabulous easy breather, but there is a noticeable difference between it and the Pilot on inhalation. It uses the same exhaust "valve" (diaphragm) as the Pilot, so exhalation is the same. The performance gap between the Air 1 and the D-Series regulators is closer, in my opinion, but the Air 1 is noticeably better. YMMV.