Sometimes a clean guitar sound just won't do. If you want to get a grungy, distorted tone out of your guitar, you are going to need to add in some overdrive. You likely already have this feature on your amplifier and may not realize it. By reading this guide, you will learn how to set up your overdrive and contort your guitar sounds using your amplifier.
Look at the features on the amplifier. Find the knob that says "Overdrive" or "Gain." This will control your distortion level. Set this to the midway point for now.
Connect your guitar to your amp. Change the channel on your amplifier from "Clean" to "Overdrive." Refer to your owner's manual if you are unsure how to do this as each amplifier is different.
Play a note or chord on your guitar. It should sound distorted now. Adjust the gain/overdrive knob until you get the desired sound. Consider adjusting your tone controls as well to change your sound. You may even have separate tone controls over your second channel depending on the quality of your amplifier.
Look to see if your amplifier has a foot switch input jack. This will be like a guitar jack, but labeled differently. If so, plug a foot switch into this jack to allow you to switch between the two channels. Now you can access clean and overdrive with the push of a button.
For heavier sounds, pump the lows and highs up and take out the mid channel for your tone. For lighter rock, try a more balanced mix of tones with less gain and overdrive.
Not every single amp has an overdrive channel. If you are unsure, consult your owner's manual.