EMG active pickup/preamp?

[the fluffy badger]

I'm venturing into the world of making my own on bored active preamps and I'm rather curious about the circuit that comes with EMG pickups. From what I can tell it's basically a standard tone control boosted by a battery? Can somebody explain how they work in more depth.

[David King]

Which circuit? They make several for guitars and others for basses. The supposed buffer circuit built into the backs of the active EMG pickups has been posted here several times. If you just want an active tone boost circuit then you may be better served by searching the web.