Joel, I live in Brazil and this is a constant issue around here. There are some areas that it doesn't bothers you, but near Radio Stations it can be really annoying. I'm writing that because saw you live in Indonesia and not every country is rigid regarding Radio and TV emissions outside US (in Brazil, we have many illegal Radio Stations that keeps invading non authorized frequencies, usually the ones I tune on my Rogue). Believe me, Jerry, an Alembic can be VERY sensitive to RFI depending on how laws are loose about radio transmissions.
Using some ferrite bead along PUs cable before Board (preamp) can reduce RFI a lot, but I admit that isn't enough to solve it completely. Check if you have those cylindrical magnet inside your Bass and if both cables are winded trough it. Also, if it is a Series, be sure to match gain on Dummy with the PUs properly (there are some directions on FAQ or Must Read). It is meant to kill Hum (AC induced noise), but may help on this too.
