Greetings everyone! Right now I'm in the process of converting my Gibson Tbird do active, using an OBP-2 preamp.
It came prewired by Mr Brian from bestbassgear (great, great guy
), with a brilliant custom schematic that allows it not only to keep the original 3 knob setup, but also have active/passive option AND a tone control that works in both cases.
This last feature means that, when in active mode, I can control the basse's tone with both the tone pot and the preamp's treble/bass stack.
The preamp is being fitted in my bass by a pro luthier, so I took the opportunity to shield all cavities with graphite coating.
The first trial run revealed a small "hum" noise, continuous, when the bass is switched to active, and with full treble on.
It only becomes annoying at high volume levels, but the thing is that it doesn't behave like a grounding problem, since it doesn't make any difference if I touch the strings or the bridge or anything else.
Does anyone know if this might be a compatibility issue between the gibson humbuckers and active circuitry, or should I search for something wrong with my wiring.
