A4 Dominator 2 Blade Closed Rig

Like all the miners I have had over the years the Innosilicon A4 Dominator is a noisy beast and comings in at around 80 dBs on a good day. The fans are fixed at max speed of 100% so even if placed in a cool room, basement or Server room they are still loud!

A4 Dominator Standard Sound Level
A4 Dominator Standard Sound Level 80.1 dBs – Click to Enlarge

 

My Objective here was to have a A4 Dominator running in my front room and dinning room with out too much fuss or people noticing right away.  I needed it just enough to allow the family to have dinner or watch TV with out the noise or pitch from the miner creating a distraction.

I tried various ideas like old PC cases, Plastic creates that are used in department stores. None of them seemed to keep the wife happy in the aesthetics department until I found this on eBay.

Bitmine Coincraft Desk V2
Bitmine Coincraft Desk V2 – Click to Enlarge

It was an old Bitmine.CH Coincraft Desk V2 case that had now become to slow to mine with but the case was still good. Front and back air vents, PSU slot and room for 2 cards from the A4.

The seller had 2 at £50 each and I knew this was the case that would work. I messaged them and secured a purchase at £90 for both cases including the shipping.

Some silent mining was on the horizon and I was keen to get the new build underway.

 

First phase of the build was to install 4x 120mm Noctua Fans for air flow across the cards. This looked pretty good at first and I was optimistic with the design. I used the original heat sink mounting screws to firmly fix the hashing boards to the base of the case. This involved drilling new holes in the case.

I tried the cards in various location inside the case but found this layout to work the best. The fans were set to blow air from left to right.

Quite A4 Dominator
Quite A4 Dominator – Click to Enlarge

 

Unfortunately this air flow was not sufficient and the miner slowly started to heat up after about 15 minutes. More fans where required and I tested some 120mm fans directly onto the heat sinks. This meant that the Noctua fans mounted in the case needed to be switched around and all 4 are now blowing air out of the case.

Quite A4 Dominator
Quite A4 Dominator

Corsair 1200W PSU was added, the Orange Pi and cable extensions for the fans in an attempt to keep the cables tidy.

Quite A4 Dominator

 

As this was still early design phase, yes you can see sellotape and blu tack being used.

Quite A4 Dominator

 

The fans still could not keep the hashing boards cool and heat would build up inside the case.  I am sure this was due to negative air pressure and the lack of input fans. Fans to push air into the case were need and so a new lid was designed to mount 4x 140mm 1200rpm Noctua’s.  This must be enough air for!

Quite A4 Dominator
Quite A4 Dominator – Click to Enlarge

The miner was near completion. Noise levels were way down, temps where good. It just needed a little tweak and the cables a tidy.

 

The miner just needed a final cable tidy and something to stop the centre fans fighting for the same air flow as this was creating a strange rushing air sound.

An easy solution to a tricky issue, some dividers to channel the air correctly so the fans are not fighting each other. This greatly reduced the air noise.

Quite A4 Dominator Final
Quite A4 Dominator Final – Click to Enlarge

 

Quite A4 Dominator Final
Quite A4 Dominator Final – Click to Enlarge

With the lid in place we finally get a miner that can sit in the same room and we can watch TV at the same time. It also acts as a great radiator, warming the room quite nicely.

Quite A4 Dominator Final
Quite A4 Dominator Final – Click to Enlarge

 

We can see the dB level of the new miner at 58.6 dBs with a reduction of 21.5 dBs down from 80.1 dBs  An amazing build that I am very pleased with, I then went onto build a second unit that is in the dinning room.

Quite A4 Dominator Final
Quite A4 Dominator Final – Click to Enlarge
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