  Guitarist and instrument designer Les Paul was an early pioneer in delay devices.
<meaning-changed>   Guitarist and instrument designer Les Paul was an early pioneer in delay devices.
 American producer Sam Phillips discovered the effect while experimenting with two Ampex 350 tape recorders in 1954. The effect was used by artists including Elvis Presley (such as on his track "Blue Moon of Kentucky") and Buddy Holly, and became one of Phillips' signatures. Guitarist and instrument designer Les Paul was an early pioneer in delay devices.