Low-impedance pickups (was: Sustain)

[pycraft@elec.gla.ac.uk (Dr M. P. Hughes)]

>2 To drive, you need power. Either a higher tension than battery or a low
>impedance pickup (DIY?). 

I've just been trying to read up about low-impedance pickups, but
information is scarce.  I'm presuming fewer turns of thicker wire are used
- hi-Z pickups use about 6000 turns of 40SWG wire.  Anybody got any ideas? 
(I'm assuming they've been off the market since Gibson dropped 'em in the
70s)

Michael

Dr Michael Pycraft Hughes      Bioelectronic Research Centre, Rankine Bldg,
Tel: (+44) 141 330 5979        University of Glasgow, Glasgow G12 8QQ, U.K.
    "Wha's like us?  Damn few, and they're a' deid!" - Scottish proverb