Again, I don't know whether you want to be able to hear and record your guitar or just hear your guitar.
This unit (and I do not really know if it is good or not since I do not own one) is a unit to record and add software (I guess) effects to a guitar whatever.
I would ask first to see if it is what you want, because in the end it looks as if you also need the computer to be a DAW (digital audio workstation) instead of a computer you just plug the guitar into and hear through the soundcard of the computer and speakers hooked up to that.
That unit will work that way also I suppose, but again, consumer beware when buying items is all I can say.
http://www.sweetwater.com/store/detail/StealthPlug/ Otherwise there are cheaper about same price audio/interfaces like the m-audio m-track something like that for a bit more which is a real low end audio/interface.
So is this unit I guess in the link above so perhaps it is just for guitar though and nothing else.
??
Another interface (I don't know if it works good or not)
http://www.sweetwater.com/store/detail/Alpha/ I suppose you will have to look around and see what you want really.
A high-Z input (high-impedence is what you need for guitar either with an amp or a recording unit (audio/interface) or anything used for guitar as an input for it.(however with like a Boss ME-25 or some unit like that for a guitar then the output can be low or medium impedence (synth like) or perhaps high impedence (that would then go to an amp). (the outputs may both be low impedence whether amp or direct input to audio/interface (I think mine are).
http://www.sweetwater.com/shop/guitars/guitar-pedals/ So actually I give no advice really or really want to.
or I am not hooking up your guitar and playing it for you, I need practice on my own guitar.

(just a little humor).
And if you have a sound card in your computer you probably can take the headphone output of that Marshall 1-watt amp and yes, plug it into the line input (mini-plug connection if that is what it has - like a headphone output on the Marshall or iPad connection for headphones) and use that to plug into your sound card in your computer and hear it on your computer with a mini-plug stereo cable used for such purposes bought at your local wal-kart store or wherever.
(3.5 mm plugs instead of 1/4" guitar type cable plugs.)
Then you may need something like that if you can find a copy of it:
http://www.amazon.com/4400-Guitar-Chords-Roy-Smeck/dp/0898988381 good luck and sore fingers to ya.
post edited by spacealf - 2014/03/13 14:37:02