Scubapro S550 vs S600???

[djhall]

I have been looking at a MK25/S550 combo for $265 at leisure-pro. I've dove with both the MK25/S550 combo and the MK25/S600. I liked the S550 better, and the LDS tech told me something like the following: The S550 is tuned to its best performance when serviced each year and is not adjustable. The S600 is tuned to its best performance as well, but can be "de-tuned" using the extra adjustment knob if the diver chooses. I could have made the S600 feel like the S550 if I had known how to set the extra knob to its best setting.

Ummm... Okay. If that's the case, why would I spend the extra $60 for a S600? Are there any other differences between these to regs? People seem to love their S600's here, and I don't think it is because you can "de-tune" them.

 

[jamiei]

I believe the S600 is lighter and smaller. I use the S600 myself and haven't personally used the S550, this is just what I've heard others say about the differences.

 

[pendive]

The S550 is literally the S600 w/o the adjustment knob and with a different looking face plate. If you bought a S550 and regreted the decision, any Scubapro dealer can change the cosmetics and add the S600 adjustment knob (for a fee). When both are service correctly, they breath identically, and rarely is there any reason to detune a reg (in the recreational world). And the S550 is slightly lighter (no adjustment knob) but otherwise identical in size.

ScubaPro Dealer. And the only reason not to buy from Leisure Pro is that you lose the lifetime parts warranty. Happy diving.

 

[jamiei]

the parts warranty doesn't mean squat with my dealer... he charges more just for labor than others do for parts and labor. I think he figures that he should get the benefit of the free parts, not me...

 

[redacted]

1. Detune the reg if adverse conditions like surf or strong current cause freeflow.

2. Turned to the hardest breathing condition, the LP seat should seal against to orifice without being under tank pressure. This would allow you to soak the system in fresh water for cleaning.

3. If you decide to tune (set the tension on the balance spring) your own reg, it is quite easy to adjust the S600 without the special tools, and then do the fine tuning with the knob. With the 550, you must be more accurate setting the balance string tension - not that hard to do if you don't mind a couple extra rounds of small adjustments.

That price looks great so it may be hard to justify that knob.

 

[pescador775]

The knob has been around a long time. Originally, it was added to the 60's era SP unbalanced regulator to compensate for variations in 2nd stg supply pressure. Double hose divers who didn't like the 'easy breathing' jet like effect of the single hose seemed to transition better with the adjustable second. They could detune to create a bit more resistance. The knob can be used to detune when surface swimming or entering. Also, the knob can be used to stifle freeflow when the diver is pulled by a sled. Some divers like to adjust their regulators to slight freeflow with the knob turned out. Then they know they have a wide range and it reduces pressure on the 2nd stage poppet. When I transitioned to single hose I bought a SP second to use with Conshelf first stg. Since both stages were instantly adjustable I figured that tuning was more practical in the field. (Adjusting intermediate press and twirling the knob is a method to get rid of 2nd stg 'honk' when such occurs). Also, I didn't trust the open port piston. Today, I use a MK 20/G250HP. Still turn the knob in slightly, out of habit, maybe.

 

[djhall]

awap once bubbled...
1. Detune the reg if adverse conditions like surf or strong current cause freeflow.

2. Turned to the hardest breathing condition, the LP seat should seal against to orifice without being under tank pressure. This would allow you to soak the system in fresh water for cleaning.

3. If you decide to tune (set the tension on the balance spring) your own reg, it is quite easy to adjust the S600 without the special tools, and then do the fine tuning with the knob. With the 550, you must be more accurate setting the balance string tension - not that hard to do if you don't mind a couple extra rounds of small adjustments.

That price looks great so it may be hard to justify that knob.

Okay... so basically, what I am getting out of this:

1) I can temporarily detune a highly sensitive 600 if I run into problems with surf / strong current / surface swimming & I can either live with it or have the regulator permanently detuned if it is a 550.

2) The 600 is safer to soak/immerse without being pressurized.

3) The 600 may be easier to work on myself, because I can fine tune around my rough internal tuning with the knob.

And, If I do get the 550, I can always pay my LDS $$$ to have it upgraded to a 600 later.

Thankfully, my LDS is pretty understanding... they discount what they can, and I will buy from them as long as they are not more than 25% higher or so. Scubapro will pull their authorized dealer status if they catch them selling below 10% off MSRP. MK25/S550 MSRP - 10% = ~$400 = ~150% of leisure-pro's $265. Ouch! Of course, based on what I have read elsewhere on the boards recently... it may be worth the extra $135 if I could talk them into selling me parts kits and letting me photocopy their service manual in return for buying from them. I'll have to ask them about that... who knows, they may even be able to sell me a service manual.

 

[SimonN]

or have the regulator permanently detuned if it is a 550

So many people tune their regs so that they freeflow at the slightest touch on the pretense of 'performance'. Realistically, I don't consider a reg tuned like this to be properly tuned. A properly tuned second stage will give you the gas you need without free flowing - without the need of any adjustment nob. You do not need a reg to force feed you.

SP second stages are easy to tune... the other weekend I did a field tuning of my R380 on the beach using a plastic picnic knife cut into shape with my dive knife ;o).

Go for the 550 and spend the difference on Vance Harlows book - propably the single best reg investment I have made.

FTR: I own or have used most of the SP range of regs and with the exception of the MK2+ (which is nice and cheap for a deco reg) I cannot tell the difference with any combination down to 50M on air - tuning/servicing plays a much greater role. If I was to buy it all again, however, I would get Apeks DS4s and ATX40s for everything.

 

[Munin]

The S600 also has an anti-set poppet. The 550 does not. In case you don't know, that takes the spring pressure off the lp seat when it's not pressurized to reduce wear.

As everyone else has said, adjustments are a personal preference thing.

 

[captJohnBoy]

I've got the S550 but think the S600 would be better with the smaller footprint. Since I plan on "upgrading" to the S600 and giving my wife the 550, I'll soon know the differences.

Besides, the $60 or so isn't that bad for a smaller footprint.

Also, my LDS tuned the 550 to optimally free-flow at surface in the water. He said he did this so that under pressure, I would have the easiest ability to draw in a breath without a lot of labor.

What we need is one that you can use to 40 to 42 degrees F and doesn't cause an "ice cream" headache to occur when the temp drops at depth. On my last dive at 46F, the dry suit was warm (with 300G polarfleece) but the mouthpiece was nearly freezing. I have always used the SeaCure mouthpiece but it still doesn't help the unit area against my exposed skin, outside of the hood.

Any ideas on how to prevent a "cold headache" like this? (other than to dive in the tropics?)