WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
Building, troubleshooting and testing of these amplifiers should only be
performed by someone who is thoroughly familiar with
the safety precautions around high voltages.
Searching has pulled up way too much discussion so I'll just ask directly: could you point me towards a consensus very good or even best ultra minimalist 12B4 line level preamplifier schematic?