Macbook pro Line-in not being recognised, anyway around this?

Hello,

I have been trying to use a phono/mic preamp through my macbook pro to record on garageband however the laptop is not recognising that there is a line-in, it thinks they are headphones. The computer has only one jack, which is used for both line-in and line-out, there used to be a function on older computers to select what the jack would be used for, line-in or line-out, however this has been since removed.

I have plugged the preamp into an apple computer with a dedicated line-in and it has worked fine.

Is there anyway I can get the computer to recognise the preamp? Could a phono-to-USB adaptor work perhaps?

Thanks,
Bigyouth

What happens when you send a signal through the pre-amp and then into the Line In jack on your MacBook Pro, does it then recognize it as input?

No it just stays as headphones

its a mid 2012 13" macbook pro and it appears that it does not have a proper line-in, nor the ability to select what the audio port is used for.

However, the combination audio port allows the use of headsets with microphones. So maybe something like this would work?

3.5mm microphone adapter cable for iPad iPod and iPhone with headset connection | eBay

It might work. In any event the seller says it can be returned except that you must pay return postage. I wonder if the reason your MBP won't recognize the output from the pre-map is this mentioned by the seller:

Some laptops and mobile devices will not work with all external microphones. This is typically caused by an impedance mismatch between the microphone and the device. This is due to hardware incompatibility and is not a limitation of the Conversor adapter.

Generally, the output impedance from a pre-amp is very high in order that it does not load down the circuit it's connected to.

It is too bad that Apple has combined the line input and output into the one jack. Seems like if something was working well before, why change it?