Making your ARC 110/210/220 dead quiet
One of the problems with latest ARC gear, is that they come equipped with fans. This may or may not detract from the music, depending on the room, listening position and the background noise. In my room the OE fans were clearly audible on quiet passages, which I found quite irritating.
In order to solve this problem, I paid a visit to the local shop that specialises in computer cooling accesories - they sell gazillion of different fans, water cooling systems etc.
I reffered my problem to the salesman and he recommended me two different 80mm fans - Thermal BTF80Pro (10 EUR) and Noctua NF-R8-1800 (15 EUR). In their lowest settings, they are said to generate as little as 9dB/1m and 7dB/1m of noise respectively.
Anyone who ever dealed with fans knows, that the biggest source of noise is not the noise generated by blades/air, but rather the vibrations transmitted to the computer/amp chassis which turn into noise as soon as the fan is fastened.
So even though the fan my be dead quiet when you hold it in your hand - it starts to make noise when it touches the chassis.
Because of that, the Thermal fan, which on paper generates 2dB of noise more than Noctua, but prolly also has a better bearing/motor assembly design, turned out to be much quiter.
The amp is now almost dead quiet - meaning that in the middle of the night, in my sound proofed dedicated listening room (read: with EXTREMELY low background noise), I can BARELY hear it from my listening chair when NO MUSIC is playing.
At the same conditions, but during the day (slightly higher background noise) I cannot hear it at all so I can say that it really is dead quiet.
I cannot recommend this upgrade to any ARC user highly enough.
Here is the pic of the 2 fans I tried + ARC one (middle):
To allow easy fan exchange/upgrade in the future, I soldered in computer fan sockets: