Yep. Try to get some contact cleaner into that Alps pot.
I'm sure you know that those pots were noisy when motorized, but were quiet when stationary.
Another thing that I just learned earlier this year is that the multi wire connectors can cause noise in those units. Mine got worse and worse until I changed out the pot... only to find that wasn't the issue. I was about to send it off for repair when I discovered the problem was in the internal connectors. Spray and clean those, along with your tube sockets.
