Well to get a distortion guitar sound you will need either a distortion or over-drive channel of your amp or a distortion pedal. No, you do not need to settle for another amp as you can easily get a distortion pedal. As the guy above me has posted, the Boss DS-1 will do you fine. It's built very well and has quite a range of sound. However, you must know that you will not be able to get a good over-drive sound. Yes, I know as I own one. Also, the quality of the sound depends on the guitar and amp you are using. If you're on a budget then I would also recommend you the Digitech Hot Head, a great deal for the money. If you are not and have about $150 to spend on a distortion pedal I would recommend you the fulltone catalyst.