Whistling sound from the latest batch of S9's

[empanadas]

hi

we just got a S9 (january batch) with a rear fan exactly as the picture
YATE LOON 12BM-12D.
That fan came broken.

Is different from the front fan that bitmain sells as part.

Do you know which commercial fan can we use?

From the YATE LOON page it only blows 82.5 CFM @ 2300 RPM
http://www.yateloon.com/en/product-330977/DC-FAN-SERIES-120x120x38.html

But we think it must go 6000 rpm and blow over 200 cfm

Thanks

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[HoleShot]

lots of fans to choose from on digikey.com or mouser.com

Please let us know if you find something better

[aiva1982]

As a lot of russian customers said the best fan for s9 is Delta PFC1212DE. You can find it on aliexpress or ebay. Pretty cool air pressure with excellent CFM. Maybe it will help you. It may be with non-standart PWM 4pin connector, but there are a lot of info how to re-pin it.

[GuitarKaos]

I know this hasn't been posted to for a while, but I actually found a few tricks that I wanted to share here for anyone that comes across this post...  (because they are tired of their S9's wailing at them possibly, like me)

I have 2 S9's from the Jan batch, and both have a distinct whistle in them..  One has two Nidec fans, the other has a Nidec and a Yate Loon..  They both whistle horribly at full spin and maybe within 55% of full spin all the way to the top (full spin in my head being 6000rpm)...

This at least worked for ME...

The S9 with the two different types of fans...  It came with a Nidec on front and a Yate Loon on back..  I just swapped them..   Putting the Yate on the front and the Nidec on the back still gave it a whistle at full spin, but running between 4000rpm and 5000rpm where they stay in my setup, no more whistle... 

The S9 with two Nidec fans...  I repositioned the center board just a little bit, by wedging something VERY small (I used a rolled up dot of gapher tape) under the card right at the edge...  This made the center card sit VERY slightly higher in the front of the ASIC than in the rear, and changed the path of the airflow very slightly..  There isn't much play so it doesn't change it much, but that simple change also killed the whistle in mine at the mining spin speed (this one goes between 3800rpm and 4800rpm typically)...

More or less, both "fixes" just changed the wind going through the ASIC just a little bit (which was enough in my case)...   

Can't say this will help anyone here, but those small changes made a huge difference for my noise level and sanity...  Maybe these ideas will help a few others come up with other ideas along these lines (if these don't help of course)... 

Happy mining everyone....  and may it be a more silent mining for you all..

[OldRadio]

Hello Gentlemen...

"WHISTLING": in the Antminer S9...

MYSTERY SOLVED...

Well, I have owned hundreds of the Bitmain Antminer S7's, S9's and S9i`s.  Last night while re-purposing my Antminer S9 machines, I ran across "ONE" machine that was giving me the horrible "WHISTLE".  Unaware that this is/was a problem, I first thought it might be a fan issue.  I have tried four different style of OEM fans.  The "whistle" is internal to the placement and configuration of the heat-sinks on the hashboards.  I tried swapping all three of the hashboards in each other's slots and the whistle did not diminish.

After swapping FANS, CASES, FAN MOUNTS and HASHBOARDS,  I finally was able to discover the cause of the problem.  When I swapped hashboards, The whistle did noticeably diminish when I replaced one of the S9 v4.317 Hashboards with a S9 v4.21x hashboards.  I looked at both hashboards to see what the difference is/was.

The EARLY model of S9 machine hashboards have a straight cut large heat-sink where ALL of the fins protrude straight "UP".  Bitmain changed the design on the large heat-sink design from straight cut (all fins UP) to a large heat-sink with a CENTER FIN WITH A "FLAT TOP" design where the center fin has a "HAT" on top of the center fin.  
Think about it this way.  A police whistle uses forced air that produces a whistle when it passes over the sideways "slot" cut into the exit port of the whistle.

So, the whistle is caused by the forced air passing over the "new style" heat-sinks (center fin is a flat top) and creating a high-pitch whistling noise.  It's more noticeable when the machine reaches the "premium" air flow speed which allows the air-flow to reach the optimum speed that interacts with the heat-sinks center fin "flat top" to produce the high pitch whistle which is so, so, so annoying.  Also, when fan speeds are ABOVE and BELOW the optimum "WHISTLE" speed, the whistle will increase or decrease.