TS7 It's the world-famous original Tube Screamer overdrive, with something extra. A boost switch has been added for extra saturation at the touch of a button.		DS7 One of the most versatile rock distortions you'll find. Dials in a wide range of smooth distortions, from subtle to rock 'n roll crunch. Tone, Level, and Drive controls in "set and forget" PushLok knobs.