Malcolm Young his brother had been experiencing lapses in memory and concentration before the "Black Ice" project and had been receiving treatment during the Black Ice World Tour which ended in 2010. Angus confirmed that although his brother did not play on the 2014 "Rock or Bust" album: "He still likes his music. We make sure he has his Chuck Berry, a little Buddy Holly." He added that AC/DC would continue according to his brother's wishes and standards: "Look, even with his health, Malcolm was touring until he couldn't do it anymore." In that same interview, Angus stated that Malcolm was rehearsing
Angus Young he would begin using in 1977, was also used as a compressor and a booster in his signal to "fatten up" his tone. Ever since adding it to his rig, it was used on several albums in the studio for chosen rhythm guitar tracks and all lead guitar tracks. Beginning with "Rock or Bust", due to the discontinuation of the Schaffer system, Young began using a replica of the unit's preamp with a commercial wireless unit. Contrary to popular belief, Angus and Malcolm have both stated in guitar enthusiast magazine interviews that very little pre-gain, if any, is used on