Watch the Jimmy Page online guitar lesson by Jeff McErlain from Kings of Tone
Page's basic amp setup is a non master volume Marshall plexi through Marshall 4x12 cabs. It was loud and fairly clean as you can hear on The Song Remains The Same concert film. Simple as can be, he would control the amount of gain with his volume knob and sometimes use a Tonebender fuzz pedal, which he helped design, for more gain. But for the proper Page tone you must wear a dragon suit and wear your guitar down to your knees.