Mmmm I think I would possibly just get one of those fireguard or foldable playpen thing folded so he can't get to it ...
Otherwise you'll have to spend your time saying no ... unless there is nothing else in your house you don't want him to touch, you could try and explain but at 16 months it might not do much. Maybe give him something that looks 'real' like an old remote or mobile. Keep it next to the hifi unit so you can give it to him when he gets interested in it?
On the other hand if he is climbing furniture and putting himself in danger I'm afraid I'd go for the 'no' option and diversion tactics. At 16 months he may cry because you say no but he'll quickly learn he can't do it but he'll quickly get over it if everyone in the house is consistent.
Say No. And do have something he can touch in the room (with buttons and lights). If all is NO, it won't work. No for the Dvds and expensive kits, but can play with old remotes, have a special treasure box to rummaged.... As for climbing, I just keep an eye on her all the time. I taught her how to get down safely and no jumping, standing, dancing on top of anything. Pick him up and put down. DD2 is 16 months and do definitely understand no and stop. Her sister was more stubborn she did understand no, but hurried up to finish what she was doing. I that case don't say anything just remove the child.
The cover or things will stop him only shortly before he finds out how it works and he will be a nightmare every time you go to somebody else house.
We bought some sheets of perspex off the internet and velcroed them to the front of the shelving with sticky back (also off the internet). Works a treat and means you don't spend your entire day saying no