meeshu

I've tried searching for the answer to my question but have not been able to find a conclusive answer.

In the chorus of The Beatles song "Love You To", there is a what sounds like some sort of heavily distorted sound which is "played" four times during the chorus of this song.

I'm aware of a couple of other versions of this song by other artists that either use a synthesizer, or use a 'distortion' (stand alone) module with a guitar to produce this distorted sound.

Out of curiosity, does anyone know for sure what The Beatles used to create this distorted sound for their song Love You To?

Maybe a guitar in conjunction with a stand alone distortion unit/module?
Or maybe a guitar in conjunction with a synthesizer?
Or maybe just a synthesizer?
Or something else? If so, what?

Thanks!