Hi wirewiggler.
Nice buiding...
I wonder how many degrees you have set the fan control board for starting and if your PWM fans stopped after the lowest temperature value..
Ιn my amplifier the USSA 5.0 that works in 1.3A , i have applied with great success two PWM fans outside the heatsinks that are controlled by this
DC 5V 12V PWM Speed Controller Fan Speed governor 2 3 4 Wires Computer Temperature control Switch for PC CPU Cooler Fan Alarm|Switches| - AliExpress
My fans stopped if the temp go lower than -2 or -5 C degrees from starting fans temp 40 C
Regards Nikos
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How do they compare with Dell CPU coolers model - FD841 version 1.0 (available from ServerWorlds in MN)?
I’m fine with a case 400 mm deep - but would like if either fan would allow one U size less, ie a 3U.
The other consideration would be internal height. The 4U has 165 mm.
Would the 3U’s be enough - 120 mm ?
Ιf you mean the noise from the fans is very very quiet(only PWM fans) you can also adjust the rotation force to 10 levels I use this...
Slip Stream 120 PWM - Scythe EU GmbH : Scythe EU GmbH
Slip Stream 120 PWM - Scythe EU GmbH : Scythe EU GmbH
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I use Dell FD411s in my 3RU Modushop Slimline case - 350mm deep - with an 80mm Slimline Noctua fan underneath each CPU Cooler (and holes cut in the base panel).
Works very well in terms of heat but, even though I'm using the additional cable which comes with each fan (which reduces the voltage getting to the fan and hence its speed) ... I am still annoyed by the fan noise. 🙁
See pic.
Andy
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#andyr
Do you use the capability of pwm fans 4 cables by controller board? or use the fans simple use two cables?
Do you use the capability of pwm fans 4 cables by controller board? or use the fans simple use two cables?
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The fans are PWM capable (having 4 wires) but I am just using 2 wires - given the ancillary cable already cuts down the voltage going to the fans.
Andy
Ah, 10 levels.
And the Slip Stream’s specs include: Noise 0 - 26,50 dBA
26,5 would be at maximum … compared to the level of the music. I would imagine would only be heard where you were playing loud, and then the volume suddenly dropped because of the gap between tracks on vinyl
… An effective solution
@otto88
i set force in 5 level this force this is enough for me to turn my temperature heatsink from 40C degrees to 38C the time the fans turn on is about 3 minutes. my temperature room about 30-32 C . Ιn truth nothing is heard.
@Andy PWM fan inside has a chip maybe you use all cables by controller..when i use the PWM fan with two cables make a noise at start or at low turns..
but if you need all ten fan power levels to achieve the desired temperature then surely without music something will be heard ....
Let Χkr971 forgive me for being off topic.
i set force in 5 level this force this is enough for me to turn my temperature heatsink from 40C degrees to 38C the time the fans turn on is about 3 minutes. my temperature room about 30-32 C . Ιn truth nothing is heard.
@Andy PWM fan inside has a chip maybe you use all cables by controller..when i use the PWM fan with two cables make a noise at start or at low turns..
but if you need all ten fan power levels to achieve the desired temperature then surely without music something will be heard ....
Let Χkr971 forgive me for being off topic.
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Ah, 10 levels.
And the Slip Stream’s specs include: Noise 0 - 26,50 dBA
26,5 would be at maximum … compared to the level of the music. I would imagine would only be heard where you were playing loud, and then the volume suddenly dropped because of the gap between tracks on vinyl
… An effective solution
The dB rating on the Noctua 92mm NF-A9x14 PWM 2200RPM Fans (14mm thickness) when using the 'LNA' (Low Noise Adapter) cable is 13.5dB. This reduces fan speed from 2200rpm to 1700rpm.
Even so, I can hear the 2 fans in each case when standing above them. 😱
Andy
The PWM controller is ideal but the 'LNA' cable performs some of what it does ... without the sophistication of varying the fan speed.
Andy
Andy, is there not enough space for, say, 120 mm fans?
OTBE, 50% bigger fans, as a rough rule, might be ~ bit over twice the cooling …
Allowing much lower fan speeds
……From Wikipedia, quoting the Handbook of Noise and Vibration Control, with my emphasis -
fan noise increases with the fifth power of the fan rotation speed
Many holes on top?
And “taller” feet might allow more natural or easier convection?
Noctua NF-A9x14 PWM 2200RPM
Rotational speed (+/- 10%) 2200 RPM
Rotational speed with L.N.A. (+/- 10%) 1700 RPM
Min. rotational speed (PWM, +/-20%) 500 RPM
Υou are already very high at 1,700 rpm unless they are necessary for the desired temperature ...
Andyr
I have the impression that you are not using the fan properly .... you need a PWM controller
Rotational speed (+/- 10%) 2200 RPM
Rotational speed with L.N.A. (+/- 10%) 1700 RPM
Min. rotational speed (PWM, +/-20%) 500 RPM
Υou are already very high at 1,700 rpm unless they are necessary for the desired temperature ...
Andyr
I have the impression that you are not using the fan properly .... you need a PWM controller
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Υes indeed...Βut mine bias for USSA 5.0 is 1.3A I dont know for Alpha Nirvana ...i think more...i wil post pictures with all respect for this thread..
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That's a very interesting concept Otto. 🙂
I had not thought about using a much larger fan - to be able to lower the fan speed (and therefore noise!).
But surely the questions are:
1. Is a 120mm Noctua fan available in the same Slim Line depth I have with the 80mm fan?
I will have to investigate.
and
2. If the fan diameter is so much greater than the area of the CPU cooler fins ... is that of any benefit, in terms of cooling efficiency?
I wouldn't like to reduce cooling during our summer ... but during winter - that is certainly a possibility. 🙂
And in terms of "Many holes on top?" ... yes, it's a Modushop fully vented aluminium top panel.
And "taller feet might allow more natural or easier convection?" ... there's about a 25mm gap with the special feet.
Andy
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It is a little early in the game to gauge the noise. I have to assume mine are running about 50% at 90 degrees f ambient. I will give you better idea when I get some batteries for my optical tachometer and find my db meter and also completely boxed up. I am running the PWM controller Vunce and X used with the Dell fd841. The fans are the Notuca NF-a9. My bias is 1.63 with the 22 ohm resistor offset is 4mv and 10mv it just is not worth try to chase it any better than that as far as I am concerned.
Bill
Bill
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