Need help in connecting electric guitar to MacBook air using audio jack

Can't be done unfortunately, the jack isn't a combi so even getting a splitter won't work. You'll need an external DAC.

If you're on a budget, something like this would do the trick: http://m.creative.com/uk/p/sound-blaster/sound-blaster-play-2?gclid=COjYttCqs9ECFe8K0wodzKwPOA

 

As mentioned you need an external soundcard with audio-in.

 

If you want studio quality recordings on a budget look no further than the Focusrite Solo... It is designed for musicians/guitarists and comes with software for recording and lots of plugins.

If you're on the new MacBook Pro (USB-C) you could look at the M-Audio M-Track 2x2 which uses USB-C helping you avoid the use of dongles.

 

Alternatively you could try something like this, works well on iPad.

http://www.ikmultimedia.com/products/irig2/

 

Actually, you need a DAC that specifically has guitar or "instrument" inputs. The signal level is quite different from either "mic" or "line" inputs.

There are quite a number of such DACs, ranging from simple cables, with embedded circuitry for recording from a single instrument, to "mixer" type boxes that include mic & line inputs and computer outputs. Prices in the US will begin in the $10-15 USD range.

 

Just get a RockSmith cable. It's USB and works great. I use it as an audio input to my Mac all the time from my guitar.

You can get some iRig and Apogee adapters as well, but I've found the RockSmith Cable to be the least fussy option.