Looking for Silent Fan Cooling f my ARC Tube AMP

Do not allow the fan to blow directly onto the tubes as this will cause microcracks. Place the fan's exhaust away from the amp, which will allow the cool air to be "drawn" into the amp, thus enhancing the natural cooling convection effect to take place.

Yes definitely draw the heat away vs, blowing air into any component, tubed or not. A variac will reduce line voltage to slow down & quiet that fan, but don't use an SCR dimmer (even one for motor control) because they're typically electrically noisy. Lutron may be the exception but I've never tried one.

I don't get it. ARC's VT100 mk2 has a fan mounted inside the chassis. It's on the bottom of the amp, and I haven't checked to see if it is blowing up or down. However, what IS that fan doing besides bringing new air into the chassis for cooling? Is the VT100 mk2's design flawed in that respect?

I actually have my fan behind my rack circulating the air away from the rack. But I need a totally silent fan.

As for quiet fans, I found this site a while back that sells ultra quiet fans for PC's. I've never dealt with them so I can't attest to the quality of their service, but you might check out their catalog and see if there are products available that fit your needs.

http://www.endpcnoise.com/