Looking for Silent Fan Cooling f my ARC Tube AMP

Correct me if I am wrong, but I thought that blowing air onto hot tubes can result in "microcracks" and is not recommended.

That's what it says in my Jadis manual as well. However, ARC does use fans in some of its models (I think my M-300/Classic 150s had them; that I can't recall entirely will testify that their noise was not intrusive), and I believe they make them for installation in enclosed rack/cabinet enclosures. You might want to check with ARC about this--what model amp do you have, anyway? You could ask ARC if a fan is really necessary for your application as well.

My VT100s have fans in them. Fairly quiet ones, too. Given the cost of retubing one of those guys, I hope I'm not developing "micro cracks!"

Might check an electronics parts outfit, the fans look like the 5 1/2" ones found in computers. I think they make "whisper" versions that are pretty silent.