I currently have:
a line 6 spider jam amp 75watt i believe which can handle a mic (xlr), guitar and also has an aux jack......but WILL NOT accept stereo in any port
a tascam us144 interface...2 1/4" and 2 xlr inputs..midi in and out, rca outs
i have a directbox which I don't use....
and i also have one shure sm57

and I've been using Garageband on my macbook for recording, and originally I was using my amplifier as a speaker with the headphone jack on the macbook....

I was told that this could hurt my sound card and that I should change it like this....
NOW...my signal goes....guitar to 1/4" to interface to usb to computer to usb to interface to rca-1/4" to amp
once at the interface the signal is sent to the computer and then back along the same usb port......and the interface takes work away from the sound card.......

The problem I'm having is that my amp only accepts mono signal...my goal here is to get a good recording quality out of my setup as well as play music to jam with sometimes....someone at guitarcenter :/ told me to get some monitors...

Last edited by dailyplayer at Sep 1, 2010,
I wouldn't use an amp as a "monitoring system". As you discovered it is mono which is only acceptable for speach. The second major disadvantage is, that an amp has a limited frequency-bandwidth.

The good news is, that on a mac it is very easy to configure monitors. To use monitors you need to have the possibility to adjust the volume on your interface.

If you want to buy good monitors at a fairly cheap price, I'd suggest to listen to a pair of FOSTEX PM 0.5 mkII.
To test monitors take some music you're familiar with and listen through it using different monitors, take a bad mix with you, because good monitors have to show you how bad it really is.