How to keep my stack of Adcoms cool...

Yeah, don't put them inside cabinets. All right, you probably didn't want to hear that, but that's the answer. Fans might help somewhat, if they're positioned in a way that really circulates air over and past the amps. (But if both intake and outflow are in the back, they won't do that!) But fundamentally, heat-generating electronics do not belong inside wooden boxes. I'd consider getting a separate rack for them and tucking them in a corner somewhere.

Both good responses. However, the entertainment center option was a compromise solution, taking spousal approval factors into consideration. I am probably stuck with the unit (and it's fairly nice, for what it is). I am currently thinking about trying to re-engineer the door hinge so that it can be laid/slid flat with the side of the unit when open.

In the meantime, I plan on adding some ventilation holes at strategic locations. Hmmm, maybe just one fan, sucking air out near the top rear of the cabinet, with ventilation holes at the bottom near the front (underneath the amps, facing the floor, so you won't see it).

Still, I'd need to find a very quiet fan that still moved a good bit of air...

Thanks for the advice, Tom.

You can't get around the fan in a closed rack. However, try putting the amps on the bottom of the rack near the floor. Don't play with the 555 when its gets hot it shuts down. Their are also passive chimney designs. The first guy responding was describing a type. Most are pretty unsightly.

I'm building a closed cabinet for my equipment but it has a fan that exhaust out the back.

if you DO decide to put a fan in to suck the air out, you might want to locate it in the middle of the back instead of the top. cause then it will pull all the heat to the top

Locate a squirrel cage or better yet axial (like a jet engine) in the crawlspace or a nearby closet. Put a small furnace type fiberglass filter over its intake so you are blowing fresh, clean air (clean filter regularly). Run the fan's output to your cabinet via insulated flex duct or similar (a good S-bend will cut noise out of the fan to the cabinet). Dump the air supply into the bottom of the cabinet. Cut ventilation into the top rear, a bit smaller than the area of the hose's crossection.

You'll end up with a slightly pressurized cabinet, this will help keep dust out- fringe benefit. You'll also get good, quiet airflow through the cabinet. Pull the shelves the amps are on and take a hole saw to them (don't put holes where the amps' feet go...) If there's no flow around the back of the other shelves, give them the old swiss cheese treatment as well- the air will move up with the convection currents and out of the cabinet.

Any "muffin fan" type fan you cabinet mount WILL make a racket, if not from it's own rattling, then from vibrating the back of your cabinet.