Beatles: In Mono Boxed Set (14LP, mono, Mint) [Kollectibles]

The set was released on compact disc on September 9, 2009, coinciding with the release of the remastered stereo recordings, the companion set The Beatles (The Original Studio Recordings), and the video game The Beatles: Rock Band. The remastering for both the mono and stereo versions was overseen by EMI senior studio engineers Allan Rouse and Guy Massey.

On September 9, 2014, the boxed set was also issued on 180-gram heavyweight vinyl, with each record mastered directly from analog tape sources, unlike the digital remasters used for the CD version.

The Beatles in Mono was released to highlight that most of The Beatles' catalog was originally mixed and issued in mono. In the 1960s, stereo recordings were a relatively new concept in pop music and did not become the standard until the latter part of the decade, which is why earlier Beatles albums were mixed in mono. By the late 1960s, stereo had gained popularity and become the norm, leading to the final Beatles albums—Yellow Submarine, Abbey Road, and Let It Be—being mixed exclusively in stereo. Many believe the mono mixes better capture the band's original vision. For instance, with Sgt. Pepper's Lonely Hearts Club Band, the mono mixes were completed with The Beatles' direct involvement throughout the recording process, while the stereo mixes were done in just six days by Abbey Road staff George Martin, Geoff Emerick, and Richard Lush after the album was finished, without the band’s participation.