mk10 first stage with a700second stage... Good idea?

[rhwestfall]

bad idea, send me the 156, its too old to use.....

 

[ryantaylor0@yahoo.com]

spare air
split fin
best bc

---------- Post added March 26th, 2015 at 09:06 PM ----------

bad idea, send me the 156, its too old to use.....

yea.. it did breath a little too smoooth last week, i may donate it

---------- Post added March 26th, 2015 at 09:11 PM ----------

can i figure out the dates on my 156 somehow?

 

[Fishpie]

Last of the BA's were satin chrome with plastic rather than rubber exhaust T.
Oval purge cover holes were later than round.....not sure the BA ever had the round holes.
Inhalation and exhaust diaphragms went from black to blue to black (with a red octo inhalation thrown in in the middle).
Solid checkered adjustment knob earlier than hollowed grooved.

 

[halocline]

can i figure out the dates on my 156 somehow?

Yours is a fairly late one, or it has had a replacement purge cover. BTW, $225 is very expensive for a used 2nd stage IMO, especially when you could get another 109 to use as a back up for less than 1/4 of the price. The only difference I suspect you might notice is that the A700 is a bit lighter. There are some subtle differences in geometry, it probably has a stronger venturi assist, but basically you won't get any significant improvement in breathing, unless there's something wrong or badly adjusted in your 156.

---------- Post added March 26th, 2015 at 09:49 PM ----------

so why do they suggest pairing the a700 and s600 with the MK25 if all of the first stages preform the same? even ones made in the 70-80s. what makes the Mk25 "better"?

The reason "they" (meaning scubapro) "suggest" you pair their most expensive 2nd stages with their most expensive first stages is because they want you to buy their most expensive regulator. Why do you think they would suggest it, as a public service?

But, look on the bright side, spending $225 on a metal 2nd stage is hardly the worst dive-gear decision one could make, and you'll have a very nice breathing regulator.

 

[ams511]

so why do they suggest pairing the a700 and s600 with the MK25 if all of the first stages preform the same? even ones made in the 70-80s. what makes the Mk25 "better"?

I am sure the MK-25 flows more air than that a MK-10. The question is does it matter.

 

[redacted]

I am sure the MK-25 flows more air than that a MK-10. The question is does it matter.

Interesting. That made me get out the caliper. Mk10 piston bore is a bit smaller than the Mk20/25 composite piston bore; but a bit larger than the older Mk20 brass piston bore. And it probably does not mater for recreational diving.

 

[halocline]

I think a big factor in the increased air flow of the MK25 over the MK10 is the rounded piston edge, which improves aerodynamic flow between the seat and piston edge. That's why they made the MK10+ with the rounded piston edge. Better air flow over the seat means less drop in IP under demand, at least theoretically.

None of this matters, the tank valve can't flow nearly as much air as either 1st stage. When they test flow rates they have a much higher capacity source than a tank valve.

 

[Couv]

.....can i figure out the dates on my 156 somehow?

Maybe. Post the serial number and we might be able to figure it out.

See this thread for a similar question: http://www.scubaboard.com/forums/re...entify-vintage-scubapro-mk10.html#post4197953

 

[ryantaylor0@yahoo.com]

its in!!! time to start building!!
is this officaly a frankin-octo now??

is there a problem with constatly taking the secondary on and off based on if im renting or using an air2? im talking about maybe once a moth or less.

 

[ryantaylor0@yahoo.com]

So here is the set assembled.
The a700 does have a noticably lighter cracking pressure. I thought it may be just me wanting to belive that my new reg was better so i got the objective wife to huff a few times and she came to the same conclusion with out hesitation.