Modding the APW9 Fans for Less Noise

Hey everyone, I'm thinking about tweaking the APW9 fans to cut down on the noise. Should be pretty simple, just throw a resistor on the positive wire of each fan and keep an eye on the temps to make sure they don't go too high! lol Just for kicks, I'm sharing a pic here!

I like the idea, the fans on the APW9 PSU are indeed a bit noisy with that whining noise, I set the miner fans at 90% almost all year long so that surpasses the noise coming from the PSU so I never really bothered, but I am sure others will find it useful, are you actually trying to force the PSU fans to run at lower RPMs? And since we are at it, I am interested in knowing the fan dimensions of those APW9, I know APW3 and APW7 have a fan size of 6cm x 6cm x 2.5cm but from the look at it seems like the once on APW9 has a different size.

If you manage and have the time, post a decibel reading from the PSU fans before and after. I am not sure from the picture, but can you start just the PSU for the test? Will keep watching as so far that sound is driving me crazy   Thanks

Hum ... i don't take real size, but i thinks the APW9 fans is 40x40mm and i thinks the speed is arround 10/12000rpm ! smaller than APW3 / APW7, and the APW9 fan is very lound :s, is arround same noise than 120mm fan at full speed ! very bad ! So, i need to improve this :p For this mod, i go to slow ! is my better machine !!! i don't need to broken this lol (T17)

Please tell us how this mod has progressed for you.

silly thought... can the PSU be left open, and the fans took out? to avoid overheating I am thinking of placing some 3 or 4 140mm arctic (pc) fans, way silent (2000rpm) to blow on the PSU? My question: Would the PSU start if no fans are present? ie fail-safe to avoid overheating? If yes, can the PSU power the other fans and 'tricked' into believing they run at the 'safe/recommended' speed of its original fans? I would not go through all the trouble, but this high pitch sound is a bit annoying

A good question. I don’t have one on hand. With shelter in place I wont be driving to the main location any time soon.

Inside APW9, have 3 connector for this 3 fan... So, the psu don't read the fan speed ! each fan have only two wire, so no "wire" for tachymeter ! I thinks, the psu have security for "fan lost", and i thinks only read intenssity at each fan, if on fan "show" no amper, so no power, the psu enter in security mode ! IS NOT POSSIBLE left open the psu, the reason is simply, the way of air flow is totaly wronk ... but, i have inspected this, and, the top right and and the midle right is the most high temp zone ... but all psu need fresh air ... i thinks is possible make two fan 120mm on the left, and on litle more power on the top right All is purpose... at your hown risk, i don't tested this

Leaving it open could be useful for immersion cooling, but most likely you will end having to turn the miner 90° anyway for vertical flow. 3 wire usually means it gets rpm reporting, just no speed control. Lets hope its the other way, and that third wire is just blindly controlling speed according to some inside sensor temp.

Do you have a photo of the label on the Vents? Would love to find their specs online (cfm, rpm, etc) especially CFM.