Automatic Double Tracking - Arrival of Digital Technology

Arrival of Digital Technology

ADT became the standard recording studio technique for simulating double tracking throughout the late 1960s and 1970s until the arrival of digital technology in the 1980s (although not all engineers could apparently figure out how to reproduce the effect successfully, with Jack Douglas recalling that he was at a loss when John Lennon asked him to use ADT on his vocals during a recording session in 1980 but was unable to adequately explain to his producer how the tape decks should be set up to create the effect). With the advent of digital recording, tape- and analog-based delay methods have not been much used, though many of these analog techniques are frequently emulated using comparable digital techniques, or in some cases plugins which are used to extend the capabilities of a Digital audio workstation. Although using digital delay to simulate double-tracking produces a very similar effect to ADT, some claim to be able to hear the difference between the two (certainly one can tell the difference between digital delay and manual double-tracking, as was the case with ADT in previous years – manual double-tracking continues to be used by a number of artists). Some musicians and engineers may casually use the term ADT to refer to any form of simulated double tracking, including digital delay used in this manner, although strictly speaking the term should refer to the analogue technique. One of the very few examples of ADT being used in recent times is on the Beatles' Anthology albums from the mid-1990s, on which George Martin and Geoff Emerick decided to revive the analogue technique rather than simply use the modern digital alternatives in order to achieve a more authentic sound, feeling that ADT produced a warmer, less synthetic sound than digital delay and the latter would be inappropriate for use on recordings made on analogue equipment in the 1960s.