Just started module 3, and I bought a used Yamaha TRBX204 from a friend, who bought it from a friend of his. It’s a bit beat up but it does the job and so far learning on it has been fine, especially when I have the tone knobs in the middle. But when I try playing around with the tone knobs, it causes crackling in the signal, when I adjust the knobs and when I play. I also noticed from the side that some knobs are higher up than others, see the photo.
What do I do to fix this? Is it the bass’s fault? Could it be my cable? (admittedly my cable is also an old second-hand one.) How do I troubleshoot something like this?
This is common, it’s caused by dirt - usually dust or smoke - getting in the potentiometers (the electronics part that the knobs turn).
You can clean them with a couple drops of electrical contact cleaner, or sometimes even just twisting the knobs back and forth all the way a few dozen times will fix it.
Can you loosen the allen screw in the high one and lower it? Or is it a push/pull knob? They’re sometimes used to switch between active and passive modes on a bass with an active preamp, or between two different types of tone control, for example. Does yours have a battery (small compartment on the back)?
Sometimes they just need.to.be cleaned, I tend to automatically replace them. It’s cheap and easy to do.and it’s not “dirt” from outside, the carbon that is used to make the variable resister is breaking down, typically.
