Quiet cooling fans for audiogear

Bob Bundas OK, if you say so!

Salut, Bob P.

no - the cooler air is simply spread out over a larger area

Bob Bundus, so what you are saying is that LESS cold air is is introduced by induction than by forced draft? Remember that the harm air has to be replaced by something (i.e. cold air) for the cooling of the compenents to occur. The more warm air that you remove the more cold air moves in to replace it. Frankly I don't think that it makes any difference, unless the air is really cold and then either method will be bad.

Salut, Bob P.

Bob the reasoning is so as to not introduce thermal stress points due to larger temperature differentials across a small heat-sinked area. Cold air blowing directly onto component causes a much larger thermal stress differential over a smaller area, with corresponding variations in semiconductor operating temperature, vs. drawing the colder air across a larger thermal area via drawing heat away from the heat sinked area.
Similar issues are noted when using glassware; thermal stresses occur across an even smaller glass area of a tube envelope vs. drawing the heat away.

Bob Bundas, What is the difference between blowing cold air onto the equipment and the cold air being drawn onto it by the harm air being drawn away? Any air being drawn away (heat as you say), has to be replaced by other air, which should be cold!

Salut, Bob P.

a Variac can be used to reduce AC input voltage & slow down most muffin fans to acceptable low-noise levels.
Be sure to draw heat away from the component - don't blow cold air onto it.

I second Porschecab on the ELAN ZFan2, I have one on my Plinius amp and it really helps get the temperature down when it's running on Class A mode. I bought mine from a local store, Magnolia Hifi here in the Seattle area.

Try www.pcpowerandcooling.com 20db fans. You will need to go to Radio Shack and buy a AC to Dc convertor that can power as many fans as you need. The one I purchased cost 29.99 and runs 4 fans with no problem. The fans are 8.00 each shipping included. Simply plug in the converter and run the red wire from the fan to the red input on the convertor and do the same with the black wires. You will need to splice some wire to each side to make it the correct length for your installation.

I have found that any decent 3 inch 220 volt fan hooked up to 110 volts (it will run 1/2 speed) will push enough air and will be whisper quiet. Try any electronics or electric supply stores.

Check out the ELAN ZFan. VERY NICE, and small, quiet!

Dan