Maximising gain of the one germanium open base transistor Pleiades Siemens AC151 VI common emitter RC coupled front end microphone pre pre amplifier

Maximum gain takes place at RL=33KOhm. Vb=-9V, Vc becomes -1.5V, Ic=250microamperes. It sounds very nice bringing out the edge of the voice. Signal path: reverberant room - male singing voice - Shure VP64 - Western Electric 1:2 input transformer - phase reversal (x(-1)) Neutrik XLR adaptor - Ci=56nF - Siemens AC151 VI open base - RL=33KOhms - Co=820nF - Realistic 32-1101A Disco Mixer at line in - Sennheiser HD580 - Singer's, listener's ear brain. It should be great fun to make a ring core ferrite Philips Ferroxcube output transfomer connected directly to Collector and power the transostor through this transformer with 1.5V.