Runs hot under no use
 

The gainclone I made (lm3875 kit) a month or two ago works perfectly, except that the left channel heatsink runs hot when the amp is not in use. It is within the thermal limit so it doesn't really cause problems I just find it odd. The amp sounds fantastic, and any noise is undetectable from the listening position.

If the amp is not plugged into my computer, but on, it heats up quite a lot. If I then plug it in and play music through it it actually cools down noticeably. The amp may be oscillating which could explain why the left channel runs hotter than the right, but it seems like that wouldn't stop when music was playing and it would just get hotter.

I know the question is coming so no I don't have an O-scope. Though I may be able to bring the amp into the physics department and use one of theirs.

Has anyone experienced this?

Normally it should run barely warm, so chances are it indeed oscillates. Try to swap inputs and see what happens.