The WA-MPX is an authentic reproduction of a highly revered tube preamp from one of music's most legendary eras, the 50s and 60s. Les Paul changed everything by inventing reel-to-reel tape recording with a preamp made by AMPEX (350 and 351 models). This tube preamp pioneered the birth of the rock 'n' roll sound and its "radio ready" hits, whose classic "tube warmth" defined a legendary era of music that is still sought after today. With the advent of the reel-to-reel tape recorder, this type of vintage tube preamp became a staple in the signal chain of countless hit recordings, with powerful analog tone and warmth. This iconic sound helped define the sound of artists like Elvis Presley, Kurt Cobain, Bing Crosby, Les Paul, Nat King Cole and Roy Orbison. To this day, the sound is still sought after to create timeless recordings. With premium components, original circuit design and Tape Saturation control, the WA-MPX authentically reproduces the vintage sound and warmth of the original. The WA-MPX has selectable Tape Saturation and instantly gives you a great sound.