I get this same "spit" every time the song changes on my R-41Ms. Happens if I'm streaming or listening to MP3s (haven't tried on turn table yet) and with every single song.
Volume of the spit goes up or down as I adjust the pre-amp volume (Not ideal. The first time this happened I was listening to something rather loud and it sounded like a poltergeist was screaming through the void at me 😆.) Was there ever a solution provided? Only had the speakers for a few months.