The Echoplex is a tape delay effect, first made in 1959. Designed by Mike Battle,the Echoplex set a standard for the effect in the 1960s and was used by most of the notable guitar players of the era; original Echoplexes are highly sought after.The predecessor of the Echoplex was a tape echo designed by Ray Butts in the 1950s, who built it into guitar amplifiers, including those of Chet Atkins and Carl Perkins. Tape echos work by recording sound on a magnetic tape which is then played back; the tape speed or distance between heads determine the delay, while a feedback variable (where the delayed sound is delayed again) allows for a repetitive effect.
In the 1950s, Maestro was a leader in vacuum tube technology. It had close ties with Gibson, and often manufactured amplifiers for Gibson. The first Echoplex, which utilized vacuum tubes, was designed by electronics technician Mike Battle and guitarist Don Dixon and marketed in 1961. Their big innovation was the moving head, which allowed the operator to change the delay time. In 1962, their patent was bought by a company called Market Electronics in Cleveland, Ohio. Market Electronics built the units and kept designers Battle and Dixon as consultants. Market Electronics marketed the units through distributor Maestro, and thus the name, the Maestro Echoplex. The first tube Echoplex had no number designation but was retro-designated the EP-1 after the unit received its first upgrade. The upgraded unit was designated the EP-2.These two units set the standard for the delay effect, with their "warm, round, thick echo."The EP-1 had a smaller box with brackets on the tape drive cover on which to wind the power cord. The second had a larger box with a pocket in which to store the cord. The Echoplex effect is "still a classic today, and highly desirable for a range of playing styles...warm, rich, and full-bodied."The delay could be turned off and the unit used as a filter, thanks to the sound of the vacuum tubes; this is how Andy Summers uses it, for instance.A later model was called the EP-2.
While Echoplexes were used heavily by guitar players (and the occasional bass player, such as Chuck Rainey, or trumpeter, such as Don Ellis), many recording studios also used the Echoplex.