Apple Pro speakers with mini jack connect to new Intel iMac ?

There are no adapters that are readily available to use the old Apple Pro speakers with other computers or newer Macs.

The only adapter that worked but has long been discontinued in the Griffin Technologies iFire.

These are even harder to find now and if you do, indeed find one, you're going to pay an outrageous amount of money just for an adapter that used to sell for $40!!

For the cost of this adapter, you could just buy new speakers.

The big problem with the old Apple Pro speakers is that Apple went out of its way to make sure you couldn't use these speakers with anything else but certain G4 Mac models. The connector and subsequent wiring make these speakers very proprietary and limited use without spending gobs of time altering some of the components and purchasing external computer audio amps and connectors.

Apple simply made these unusable on anything but their own hardware at that time.

It's simply not worth the effort.

Look in the Apple Store online. There are a lot of decent priced, good-looking speakers to use with your iMac.

Good hunting!

If you have a Radio Shack in your area you can look for adapters there.

There are literally hundreds of alternatives available, I'd recommend auditions some or you may like the speakers in the new computer, they are vastly improved over prior versions so you may be pleasantly surprised.