No problem at all with your clearance. The amp is well designed for cooling. Not only does it have a fan as Brf mentions, the tubes are mounted horizontally and the amp is vented on the bottom, as well as the top. The air flows through the amp and the tubes are right in the middle. Very similar to what a good computer case and power supply does for cooling. It makes perfect sense but the drawback is that it doesnt look like most other tube amps. Most people like the tubes where they can see them.
