Safely body contact & AC mixer?

[cfry]

Hi,
so I've been reading up some on safety, mainly in the awesome "Handmade Electronic Music" by Nicolas Collins. He is stressing that you should never use anything else than battery power when bending or using body contacts. Problem is, he never explain how you safely come out of the PA mixerboard or into an audio interface.

I've been using three karaoke mixers/amplifiers connected to the mains @ 220v by AC/DC adapters @ 9v each. I also have a small tv/radio that I connect with AC/DC 12volt. Then I send the signal by using body Cody contact to the main mixer, which is AC powered.

It feels like I've been taking a risk, but the controll interface is so nice that I can not live without it. Rather not die with too.
Tomorrow I plan on setting batteries on all the mixers. But at some point I have to get in to the main mixer which is AC.

So, how do get of my nine volt system into the 220 volts?

Thanks for input! I am recording tomorrow and It would be embarrassing to get electrocuted. :/

[Circuitbenders]

This doesn't really make any sense.

What does sending "the signal by using body Cody contact to the main mixer" mean? What are you actually doing with a body contact?

Whats does "how do get of my nine volt system into the 220 volts" mean? I don't see why theres any problem there. Presumably they're only connected via audio cables, and they don't carry any power. If you couldn't connect two units running on different voltages via audio cables, then nothing would ever work.

Bear in mind that you know your setup and nobody else does. I really can't picture what you're trying to do or what the problem is.