Hey guys. need some advice/help here.
I have this OLP MM2 5 string Bass guitar.
When i plugged this bass into my SansAmp Bass Driver DI, I realized there's a buzzing sound when i turn the tone knob. the brighter the tone, the louder the buzzing sound. (Volume knobs are fine. Only the Tone knob)
If tone is totally cut off then no buzzing sound at all...
oh yeah...when i mute/touch my strings the buzzing sound will go off..

When i plugged in direct to my speaker, the noise is less noticable.
But when i plugged it through the Sansamp it's really annoying and noisy.
any idea how to solve this? Thanks in advance.

P/S: I have no idea how to open up the bass and adjust the things inside. Beginner here.
I have also tried to search this forum to see if this has been discussed before...however unable to find anything close to this problem..

Sounds like your earth wire under the bridge is not doing it's job. Although then it should hum all the time. There is a wire under the bridge, maybe check there and see if it is still in contact with the bridge. Could also be that your DI Box is not earthed properly. Try playing around with your ground lift switch on the DI box. Those are the things i can think of. But why it only happens when your tone knob is up, no idea...