Hello GB, welcome. Amp (or receiver) cooling is the place to start, as you have. If the amp runs very hot, even the top mount may not be enough, depending on head space in the cabinet. I have had to place a receiver on top of the cabinet for cooling. Also, I once used a 4 1/2" holesaw(sixed for a cooling fan) in the wooden top of a friends cabinet, at the rear, above the sinks. He put cd's in front of the hole. Once that's done, we can look at isolating the cdp.
If you can fry eggs on the amp it's probably too hot
Seriously, is your cabinet closed in? If so a small silent fan to withdraw air out from the top vents and create circulation might be in order. Otherwise forget the cabinet and get an open rack.
Hang on, you're a kiwi - does it get warm there in NZ at all?
I have taken the glass door off the cabinet and there is a hole in the back of it (about 15 inches square). The amp has about 2 inches of headroom above it.
And yes it does get warm here sometimes - about equivalent to Tasmanian warmth.
I saw the temp was in the late twenties in Dunedin the other day - they must have been dropping in the streets. Kidding of course, I was there in July/August several years ago and almost froze my b... off. A bit of a change for a Queenslander.
Anyhow, your cabinet should be fine with the layout you describe, just check the amp carefully with your hand on top to be sure it doesn't get too hot. The louder you listen the hotter it'll get. And as hot air rises your other components should be okay. Are they on shelves or stacked upon each other? If the latter, make sure the lower units can handle the weight. Good luck.
