This is the second Seymour Duncan STC-2P powered EQ for passive bass pickups I have bought and am as delighted with it just as much the second time around as the first.
The first was fitted into an own-design fretless with Seymour Duncan passive Jazz pickups. This latest one into a custom built, single cut fretted bass with passive DiMarzio P/J pickups.
In both cases I have been knocked out both by the sheer range of tones available and the ease of use. Volume knob (pull for slap bass enhanced EQ), blend knob with mid point detent (turn one way for neck pickup, the other way for bridge and at the positive detent click for middle) and then a stacked positive boost and cut for treble and bass, again detented to easily feel where the neutral position is.
With those controls, the whole spectrum of tones is available - from a natural and neutral EQ to way, way beyond the scope of the un-enhanced pickups. All tones sound clean, all tones sound usable.
I will be buying this product again for future builds!