Anybody here tried to building (and designing) an onboard preamp him/herself? (with success?) I want to give it a try but I was wondering how EMG and others manage to keep the required currents so low because if what they say is true a whole btc system for example only uses 400microA. A single TL071 uses far more than that (around 3milliA iirc), and other (read better ) opamps use even more than that. Anybody have any resources about this kind of stuff? (building buffers, filters and other preamp components with low current draw [of course also low noise and thd...]) If it helps, my plan was to design a preamp which incorporates svfs (state variable filters, probably lowpass only) as tone controls. But if you have any links to existing onboard preamp schematics I am interested in those as well because i could probably learn from those.