using multple power supplies

[funkimunky]

I want to learn how to use transistors and op amps. I would like to use 3 separate power supplies to get +15v -15v and a input signal of around 2v. Is it ok to use 3 different power supplies one for each required voltage? if so what is the way to do this?

[jeroen74]

Yes, as long as they are all floating.