Octo -- Reg compatibility

[COScubaBob]

I just bought a new AquaLung Calypso Octopus (unbalanced) to use with my Zeagle 50D ZX regulator setup (balanced). When I read the documentation that came with the octo, it said the octo was not compatible with a couple of the other AquaLung products such as the Legend reg. I looked up the specs on the Legend and it's an over-balanced design while the octo is an unbalanced type. I couldn't find the reason that the octo would be incompatible but I suspect it's the balance conflict.

The dive shop said that it should be OK to use the Calypso with the Zeagle, but they didn't sound all that confident , and I don't want to take a chance just for them to make a sale.

Does anyone have any experience with this type of setup?
Or does anyone know if the unbalanced octo would be OK to use with the balanced Zeagle?

Thanks!

[nrembis]

I would tend to think if the Intermediate pressure is within the ranges specified it would work.

[keyshunter]

The AL Titan/Calypso octo (a very good octo, by the way) will work just fine with your Zeagle reg.

Your Zeagle reg, which is a very close copy of the Apeks, is just as overbalanced as the sealed Apeks or AL Legend. So called overbalancing is a function of adding a second diaphragm to seal the ambient chamber. Overbalancing is totally meaningless at recreational depths, but is touted by the marketing types to be the best thing since sex. At recreational depths (and for some distance below) the increase is very slight, and will not cause a freeflow in a properly adjusted unbalanced octo. Al's statement is just a CYA caution for people who dive to very deep depths, coupled with a marketing ploy to sell a greater number of balanced octos to the rest. At depths which can only be described as technical, the increase in IP might cause a slight freeflow in an unbalanced reg which is tuned to "the edge', but for most of us mortals, an unbalanced octo is just fine.

Having said the above, there are two more points you might want to consider. Some LDS will not want to, or will not have the parts to service octos which are different brands than the reg. Also, since there is less spring pressure on the second stage seat of a balanced reg than on an unbalanced second, theoretically the seat will last longer before it needs to be replaced. In actual practice, this may or may not be the case. Personally, I use Sherwood standard (unbalanced) and AL balanced octos, and the Sherwoods have lasted longer before they have needed service.

[COScubaBob]

Thanks to you both!

(and, in advance, to anyone else who might sill respond here)