Alembic employs active circuitry on all of their instruments. I believe that all "active" pickups are actually passive pickups that are paired with active circuitry, either external or internal. Alembic pickups are low impedance low output PUs They will work without active circuitry, but the output will be quite low. On Alembics, the "volume" is essentially a preamp, the "tone" is a low pass filter, and some add Q switches. The Q switch increases the signal at the cut-off frequency set by the filter. This system runs on 9v on non-Series instruments, and on18v on Series instruments.
Bill, tgo