I setup a circuit that amplifies the signal from my ipod/music device. I now want to be able to amplify my guitar signal from my pickups. I hook the guitar up to my circuit as if it was an ipod and I get a low volume sound out of the speaker. What I want to do is leave my ipod amp as is so I can use it for the ipod but if I want to play guitar all I have to do is hook up the preamp to the existing amp. I'm not really good with transistors yet because I have only done a few things with them. I tried using a darlington pair IC, the ULN2803APG chip but I couldn't get it working. Basically I want to amplify the guitar signal a bit more so the power amp has more to work with. Any simple ideas for my problem so I can understand how the pre amp works? I have looked online and most circuits are quite daunting to understand.