Set up issues with imac 10.5.8

Need some help with the above.

Newbie to recording music and cubase. Have hooked up Lexicon Alpha AI to Imac 10.5.8 and want to record using my electric guitar and listen through Garageband 08. Have changed the preferences for Input to “Lexicon Alpha In Out” and Output to “Built-In Output” but still no sound. Driver and licensing process all appeared to work as they should.

Can hear sound through headphones on the AI but not through garageband and not recording.

Am I missing something.

Thanks anyone in advance

So is your issue with Cubase or with the Mac settings?

If you’re using Cubase LE the sound settings on the host computers control panel (or equivalent) don’t mean much- the settings in Cubase are independent of these. There’s a “Getting Started” file under the help menu in Cubase which will show you how to set up Cubase.