ksd 705 noise problem

[lumerino]

hi this is my first thread, i have a big noise problem in my ksd 705,let me explain, since i bought it (used) i noticed big hum noise when i moved the blend to use one of the two pickups, when i used it in active mode the sound was unbearable , recently i upgraded the preamp to an aguilar obp3, now it is installed(according to the wiring diagram) all the grounds are connected to one point(the output jack ground terminal) i check all the connections and seem to be ok,

but the noise is not gone, i used the old blend pot i´m thinking that it would be a part of the problem, but i don´t know if anyone have a similar problem with this bass, could pickups be the problem?

please if you have any advice , any thread that say something or any experience , it can be helpful for me

[testing1two]

If the noise goes away with the blend pot in the middle, you may be experiencing typical single coil pickup noise. If the noise still exists in the middle position, it is likely a wiring problem or the control cavity needs shielding.