Garageband '08 - Mac won't recognize the Line-in input.

Question

I've had my mac for a while now but i havent been using the line in input to record much. The last time i used it i plugged in my electric guitar directly into my mac and on garage band i can see that it is only receiving signals on the left but not on the right. i thought it was my guitar's fault or the cables fault. Checked my guitar, bought new cables but the problem persists. But this time i'm not getting any signals at all!! i've tried everything. I bought a usb interface but that didn't work. so if anyone has any ideas please help me.

Answer 1

I have to admit that the links posted DO share some important info, however using the line input
requires some knowledge.
You have to know the difference between stereo and mono, the relative impedances of your equipment v. the line input, and most importantly what level your stuff puts out v. what level the line inpt expects and can deal with.
it is very VERY easy to screw up with the miniplugs and short out the inputs which it seems several people have already done.
I use a very VERY cheap mixer and a simple two-RCA to One-mini stereo cable. ( a pretty sturdy one)
That gets me a clean input with the channels correctly separated , impedance correct and a controllable level at a ballpark setting that does not overload or stress the input.
It may sound overly technical to you, but all of this info is contained in the manuals for things like keyboards, and mixers. Guitars are a different story and should not be plugged directly into a line input. ( Impedance and level are specialized in electric guitars and require a certain matching )
I am sorry that so many have problems with this, but there are things to know. ( Not flaming anybody here). I just recently got a USB interface.
Installation was dead easy, but I found it necessary to read the manufacturers FAQs and forums to get just the right settings to use it, hear it, and not blow anything up.
And I have MASSIVE experience. And I have blown things up in the past.
Just for instance, The line level coming out of the Mac is -10db, And I assume the input is -10db too, which is perfectly normal for prosumer audio. But if you use a mixer, and it's a pro model you will have a +4 db output (Blow up time), so you have to control it.
Impedance is usually measured in k-ohms for these things and an input should have at least 10 tiems the impedance of the output plugged into it. Guitars like a 1megOhm input. Line level devices rarely have 1 megOhm inputs, so guitars require either a preamp or passive matching device at the least. even a pedal can help with this.
Maybe this can help a couple to not fry their inputs.
Message was edited by: James Asherman
Message was edited by: James Asherman
Message was edited by: James Asherman