"Can we have a compressor on this guitar?" George Harrison had asked Norman Smith during the recording of his song Don't Bother Me in September of that year. "We might try to get a sort of organ sound."
The Beatles had some new and powerful amps to work in their favor, including a cream-colored Fender
Bassman (intended for McCartney but appropriated by Harrison), two new blackface Fender Showmans with 1x15 cabs, and 120-watt Vox 7120 guitar amps. (Guitar World report)
New guitars for the sessions included Harrison's recently acquired 1964 Gibson SG
Standard, his main guitar for Revolver, and Lennon and Harrison's sunburst Epiphone Casinos, a model that McCartney had owned for some time and also used on Revolver (Harrison's and McCartney's models had vibratos; Lennon's had a trapeze tailpiece).
Lennon also used a Gretsch 6120 during the recording of Paperback Writer on April 3, and he and Harrison might have used their Sonic Blue Fender Stratocasters, acquired in 1965 during the making of Help! McCartney, for his part, relied on his Rickenbacker 4001S bass, which he had received in the summer of 1965.
At the same session, Lennon had been voted down by George Martin when he plugged into a Gibson Maestro Fuzz-Tone. The new direction was evident from the very first track recorded: Tomorrow Never Knows. Titled simply Mark 1.
Lennon wrote the song as a mantra composed of one repeating melody line over a driving bass and drum track. "It's only got the one chord, and the whole thing is meant to be like a drone," Lennon told Martin and Emerick.
Additionally, he explained, he wanted his voice to sound "like the Dalai Lama chanting from a mountaintop." Says Emerick, "I was thinking, Well, I've got an echo chamber and... that's all! I didn't know what I was going to do. And suddenly, there it was, staring me in the face!" 
As Lennon's voice came swirling through the Leslie, the assembled group listened in awe from the control room. "It's the Dalai Lennon!" exclaimed McCartney.
Emerick also showed his ingenuity in recording the song's drums to achieve the "thunderous" sound Lennon had requested. In addition to moving the mics right up to the drum heads (earning him an EMI reprimand for "microphone abuse"), Emerick applied a heavy dose of compression using a Fairchild 660 limiter to give the drums a very forward, "pumping'' sound.
"What on earth did you do to my drums?" Ringo Starr asked Emerick. "They sound fantastic!"
To record Revolver's guitars, Emerick used his beloved Neumann U47 tube mics. These, however, he kept well away from the speakers, "normally about a foot, 18 inches away." This, he says, is where the magic arrived. "That's where it sounded good."
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