It's not a trivial task to dampen out the motor switching impulses mechanically. When the motor coils switch the torque goes from zero to close to the maximum the motor generates and then off again. The stronger the motor, the stronger the impulses. The coils are switched on and off rapidly to avoid switching losses in the transistors that drive the coils. You can change the drive circuits to slow the turn on and turn off times of the coils (I've done this with brushless DC fans) and it reduces the noise considerably but the drive transistor temperatures go through the roof because of the switching losses. You either have to put up with that heat and provide adequate transistor cooling or run the motor at greatly reduced voltages and rpms, or use a more complex motor drive circuit. Another design option to reduce the torque pulse noise is to increase the number of poles in the motor, but that increases costs. Changing the coil switch timings to occur at a point where the magnetic flux on the coils from the permanent magnets is still weak, or spacing the magnets and coils farther apart to reduce the flux gradient will also help, but again these options reduce efficiency and increase heat in the drive circuit.

It's hard to get manufacturers to increase costs and decrease efficiency for something as nebulous as quietness.

My CSP-750 (which I bought from Ed) is definitely not inaudible. I run it a little over 7V to get rid of a whining sound not unlike a hard drive's. No gurgling noises, but my flow must be little more than 2LPM at 7V. The lower pump speed costs me about 2C on the reported CPU temp. And you need a quiet system/environment for a CSP to be a noise problem.

Do you have your CSP750 sitting on foam?

He's got it completely suspended, same way I have my two MkIIs.

heh :) http://swiftnets.com/products/mcp350.asp

Bill, in the link showed above, the price mentioned ( MCP350™ Pump MCP350 $79.95) is the definitive one?

I ask this because, this particular product doesn't show on the online catalog, and there's no official launch on the news section (Swiftech site) so can you tell me if it's already available for order?

Edit: «link showed above», was meant to say in the link showed above posted by user PaulDriver =>http://swiftnets.com/products/mcp350.asp

no page for me ??
can't comment 'till announced, shortly no doubt

A little while back you mentioned that there are some exciting things in the works, how are they progressing? Any new goodies set for before the end of the years, besides the 350? I know you can't really say anything but maybe a hint as to when we can expect to see something.

glacially, but moving
you are correct, I can/will say nothing

and we know who leaked the page, thanks eh ?

thanks Gabe!

The page isn't there anymore.
Another mystery.
Resembles Apple G5 leak.

Was this a marketing gimmick?

no, we pulled it as the product is not yet released
in time, in time

lol now that was fun

Sorry, It's not like I worked hard to find the page.

I went to swiftnets, clicked the link of the MCP650 and changed the 650 to 350.

You didn't leak the page, you just drew attention to the leak. :D

security through obscurity isn't a good plan

so true . .

Hey, it worked for movies on DVDs.... right? :)

Deleted

Posted in wrong thread.
Reposted here

Some news: Roscal has announced that Laing have officially started selling the pump.
Also it seems to have gained somewhat in performance - max flow is up by 60% according to the PQ curve in this document :cool:

Anyone here speak french? Cooling-Masters.com has a review/comparison with loads of pics on the pump in French...

http://www.cooling-masters.com/artic...p?id=22&page=0

my french conversational (and Quebecois :() so technicaly french like this is way above my head

I'm not going to translate the whole thing, but if you have a specific question, ask away; I'll try to find the answer.

What's quieter, CSP-750, or MCP350?

-Ed

Danger Den's the only one reported as "definitely audible". The others (Laing, Eheim 1046 and 1048) are reported as "barely audible", "surprisingly quiet" and "with no discernable vibration".

It goes on; do you want more?

I've only tested my CSP750s, but once they are set & there's no more air in the circuit, they are innaudible. Theres a slight vibration though, so setting it on bare metal is a definite no-no

OK - in the interests of furthering discussion, I will - this is a "mechanical" translation using Systran. It's probably no better (and maybe worse) than you'd get with babblefish (also driven my Systran), but here it is.
coolingmasters article page 1
coolingmasters article page 2
coolingmasters article page 3
coolingmasters article page 4
coolingmasters article page 5
coolingmasters article page 6
coolingmasters article page 7
coolingmasters article page 8
coolingmasters article page 9
coolingmasters article page 10

Note that
1) I really don't want to step on coolingmasters' toes, so it's just translated pages, no summary page, no 'nuttin'.
2) It's in a temp directory of my under-desk PC. If you're getting to this thread when it's "stale", these links'll probably be dead - go use babblefish. They also might be unavailable because I've taken the PC apart to tinker (got a Storm waiting to go in there and a thin heater core that should arrive in a couple of days...)

"As Laing DDC is not yet really available contrary to D4, the version tested will be the industrial version without tachometer (to detect rotation) nor change of tension to calm it or the booster rocket."

hey now that sounds exciting :drool:

(better translation: the test version was supplied without tacho output or variable voltage control to calm it down or boost it up)

Don'cha just love mechanical translations? If you want to turn 'em into real translations I'm glad to send you the ones I posted (or you can just grab 'em).

n00b question
"Maximum pressure 22 PSI (1.5 BAR) "

What does that mean?

Is that how much pressure the pump can withstand?