iMac 24" and 5.1 speakers

I have a new 24" iMac and was going to hook up my logitech z5500 up to it and see that it only has the headphone jack output for sound and not a optical outlet. If i just run a 3.5mm line from the headphone jack to my logitech control module will that equal to the 5.1 sound? If not then what do i need to do to get it there?

Thanks in advance

you need a cable like this or an adapter like this.

that jack on the iMac is optical as well

you can have 5.1 sound meaning that you will have sound coming from 5 speakers and 1 sub, but it will not sound the same, or have the same quality as the speaker was intended to be heard.

What idrinorbarsaku is saying, you won't have 5.1 sound, you'll have stereo sound, using all the speakers.

If you get the optical cable then you will have surround sound.

Ill get one of those ordered. Thanks again for the info to you all