Pretty sure none of the stock activator pickups are sized to directly replace the EMG pickups but do think Alembic will make still custom sized pickups upon request. I had custom pickups made for my Quantum Five when I bought it back in 1988. Didn't care for the Bartolini's it came with. I got stock activator electronics at the time, volume and filter only no Q switch, since I didn't want to drill holes in the bass when it was brand new. Bass came with three pickups each with a mini-toggle switch to turn them on/off. Last year I finally had the electronics upgraded. Beefed up the output a bit, added a three-way Q switch and variable bass/treble controls. A lot more sonic possibilities now but the bass has always sounded great.
