Thread by @DaddyBTC_pleb

**ULTRA QUIET S9 BUILD**
60 dB with no enclosure
Running on a normal US outlet at 120V 1,000W
See thread below 👇👇 for walk-through of how to do this.

@SatoshiAnon @econoalchemist @Diverter_NoKYC @Marketsbylili

Just like the prior build for my office heater👇👇, this build started with replacement of the fan in the APW3++ PSU which makes the PSU much, much more quiet.

amazon.com/gp/product/B00…

Just make sure you also get the cable adapters for this fan (or like @SatoshiAnon you know how to splice wires):

amazon.com/CRJ-2-Pin-Fema…

There are two useful videos to walk you through this fan replacement. It is not as intimidating as it first seems. Shout out to Knox Trades on YouTube who did a similar build on an L3+ that inspired my attempt for an S9.

I've done this on 2 different PSUs and it is highly variable how much of the foam encases the fan wire. TIP: gently TUG the fan wire out of the foam little by little, do NOT cut to dissect it out. And, don't forget to buy the adapters for the fan cable (shown below).

When you put the new fan in, make sure that the fan label is facing OUTWARD and is visible. This ensures that the fan will blow hot air out of the device:

S9s come with 120mm fans stock. Unfortunately, the 120mm Noctua fans top out at only 2,000rpm. I knew from experience that I'd need a little more air flow and opted to go with a 140mm fan 👇👇that could reach 3,000rpm.

amazon.com/gp/product/B00…

This meant that I'd need 140mm-to-120mm adapters for the fans. There are MANY variants of these on eBay. I just bought the simplest/cheapest version I found (there are better options) and modified them easily with a wood chisel to ensure unrestricted flow through the housing:

I then realized that I needed more screws to fit this all together, and that the screws I did have would be too long for the adapters (because they would extend into the device and come in contact with the hash boards). Luckily, I found some in my salvage screw box:

I had to modify several screws to a shorter length which was very easy to do. You MUST ensure that none of them come in contact with the hash boards. Ultimately, I'm going to get correct sized screws (did not want to cut all my screws just in case), but for now fans are secure

With these particular adapters there are gaps between the housing and the adapter as well as between the adapter and the fan (shown by red arrows below).

In order to attach these fans to the connectors on the S9 control board you have to modify their plugs. Specifically, there are two small ridges on the plugs, at least one of which must be removed. This was easily done with an X-acto knife:

At first I tried to run things without worrying about the gaps between the housing, adapters and fans, but airflow was sub-optimal, and the leaking air was too loud. To close the gaps I turned to a tried and true low tech method: DUCT TAPE

It was finally time to put this Frankenstein creation back together and get it hashing away securing our network! I use Braiins OS and mine on @slush_pool and assumed that I'd need to set the fans at 20% to limit RPMs to <3,000. DO NOT DO THIS.

I quickly realized that I should just leave the Temperature Control set to "auto". I'm not technical, but it is clear that fan dictates it's top speed such that when the control board calls for 100% fan output, the fan goes to 3,000rpm. At 50% it is 1,500rpm, etc.

Once hashing I let things auto-tune and stabilize overnight to ensure I could assess things at a steady-state level. Then next morning I found the miner hashing around 13 TH, with fans running around 60% output at about 2,000rpm:

And most importantly, the device is VERY quiet, making about as much noise as a small quiet desktop fan (around 60 dB):

I'm handy, but not very technical. This was easy to do with a little prep and effort. ANYONE can do this. STOP USING SPACE HEATERS to heat your dorm rooms, apartments, workshops, etc. Consider a build like this to get paid in #btc to heat your space and secure our network.