Synthex Noisy Fan Replacement

Since I own the Elka Synthex, its fan's noise always got on my nerves. The fan's motor sound is kind of wobbling accompanied by some slow beating, which makes it hard to ignore. Not sure if it is just mine, but I decided to replace it with a silent one with similar airflow specs.

Original Synthex fan specs

Synthex original Fan

• ETRI_126LF2181000
• 80x80x36mm
• 208-240VAC
• Airflow direction: Into case
• 45 m³/h (at 50hz)

Unfortunately the original fan is a 240VAC fan (in Europe), which means there are not many good working silent options out there. I first bought an equivalent for 240V which was actually labelled being silent, but after I installed it, it just shifted the annoyance. The motor sound was rotating in a high frequency that was kind of present, also the airflow noise was very audible.

Screw terminals with fan wires

As this didn't work out I was thinking about getting one of those super silent 12V fans that gamers use and connect it to a wallwart with some wires going into the Synthex. A friend gave me the idea to get a power supply instead.

There would have maybe been the option to use the Synthex's own power supply, in case some output can provide at least 12V, but I didn't want to put any additional load on this old machine, that's why I opted for a dedicated power supply.

There is no soldering required as the current fan's wires are connected to a screw terminal, which I can use to connect the power supply to instead.

The parts

After some research, reading reviews and analyzing datasheets I ordered the Noctua NF-A8 FLX. According to the datasheet it will blow the air with 50.4 m³/h, according to reviews it's also damn quiet.

Noctua Fan attached

As for the power supply, I ordered a MeanWell RS-15-12 (12V, 1.3A). It comes in a metal case and has some screw terminals to connect the wires to.

Power Supply Terminals

Attaching Power supply

Next thing was to find a good place to attach the power supply to. I decided to go for the metal cover, which is part of the vent duct, close to the fan as well as close to the screw terminals. I drilled two holes into the cover, attached the power supply and connected the wires.

Vent duct cover with Power supply

Test-Drive

After putting everything back into position, I closed the lid and switched the Synthex on.

Power supply at its final position

I was impressed to say the least. The difference is breath taking. Of course there is still some airflow noise coming out, but it is really quiet and very pleasant.

Noctua has included two low noise adapters to slow down the fan's speed and make it even more silent, reducing airflow to either 41.3m³/h or 28.9m³/h.

I am not recommending doing this at all! The fan blows at a radiator where rectifiers are attached that get very hot. I have done a few test measurements with slower fan speeds, by putting temperature sensors at different spots inside. The temperatures were going up, not much though, but they were. Maybe it doesn't matter, but still...

My idea was to replace the original fan and also stick to the original airflow specifications as much as possible. The Synthex is old and rare, so why risk anything. Also, the Noctua fan is already very silent, compared to the original one it's a huge difference and hardly noticeable when you do studio work.