I have a 2010 iMac. I am beginning to research a project for my mom that involves converting old recordings a group my dad was in years ago to digital from vinyl. I have a couple of input options available but I’m seeing reference to optical input on the iMacs. It appears that this would give me the best audio quality. So, my question is this: To go from a pre-amp output, what cables, converters, et cetera would I need to in order to make use of the optical input for audio? I have looked through the forums and see some mention of the subject, but nothing that seems directly to address the specifics of this.
Thank you.
Are you sure your iMac has an optical digital input? You can look up the precise model specs on Apple’s web site.
In my opinion you’ll do just fine using the analog line input on the iMac.
– Bill
Specs say it does have an optical digital input. But it is apparently in the 3.5 MM form, a combination input for both digital and analog. It’s all a bit beyond me…
It does. I think they all do. You have to dig around in the more exotic specifications to get it to tell you.
You can do very well with the analog Line-In of the Mac and nothing more than one of these.
http://kozco.com/tech/audacity/pix/RCAMiniStereo.jpg
Unlike many Windows PCs or conventional sound cards, the Mac sound has been integrated with the machine, shielded, and tuned for quality.
http://www.kozco.com/tech/MicTests/studioLayout.jpg
That’s my MacBook Pro over on the right – analog input from the mixer. Timmy, one of the production editors on guitar.
On some iMacs, you may need to switch one connector between Line-In and Headphone-Out. But if you have both of these, you have no need to switch.
http://www.kozco.com/tech/audacity/pix/MacLineIn.jpg
Koz

As Koz says, apparently all iMacs have the optical S/PDIF input (and output). In your case you would need to buy an external analog to digital converter with optical digital out, then the appropriate cable to connect from the adapter to the iMac. There is no guarantee that this will give you better quality than using a simple dual-RCA to 1/8" stereo adapter cable from the output of your pre-amp to the analog input of the iMac.
– Bill