One of the key pieces of equipment in Moore's sound on many of the recordings with Presley, besides his guitars, was the Ray Butts EchoSonic, first used by Chet Atkins, a guitar amplifier with a tape echo built in, which allowed him to take his trademark slapback echo on the road. It is important to note, however, that this amplifier was not used until 1955--which means that the earlier Sun sessions (including That's All Right Mama) were not recorded with this amplifier.
ONe oF ThE KEy PiECeS of eQUIPmenT in MOore's SoUnd on MaNy of the recOrDiNGs WiTh pREsLey, BesiDeS hiS guItarS, Was The Ray BuTtS EchosoNIc, fiRst Used by Chet atKiNs, a guitar amPliFier wItH A tape EcHO Built iN, whiCh aLlowEd him to tAkE hiS TRadEmark slapBack eCho on thE RoaD. It IS importanT To noTE, HoweVeR, tHaT thiS amPLIFiER WAs noT Used uNTIl 1955--wHich means tHAt tHe eaRLIer sUn sEssioNS (INcLUDiNG ThaT's All right maMa) were NOt recorded wITh This AmpliFiER.