At your risk. Always use a suitable fuse in series with a battery for safety.
Output currents of the order of microamperes seem fine as the signals involved from connecting a microphone to the first active amplifying stage, front end, may be very small.
IF the signal gets high it's all the better as the first stage if it is an electron tube would somewhat peak limit the signal. A JFET would too but from basic, listening tests in not as an effective way, so it seemed. An electron tube sounded with more headroom. See older posts. See also [Hamm]. At small signal levels the distortion of class A amplifiers (electrons flowing all the time) tends to zero. The transfer Voltage out/Voltage in characteristic becomes more and more a straight line. In the same way as the earth is flat for small excursions about a reference point.
An example for relatively small, 100μA drain current is the Marantz superscope EC-7 etc series condenser microphones.
http://www.superscopetechnologies.com/images/document/pdf/history/condenser.pdf
How would a JFET K117 for example sound on the Pleiades V6 schematic? Electron tube anode current typical of 25μA (Nuvistor 7586), 50μA sounds very nice and low noise. What would be an optimum FET drain current for such a circuit?
Reference:
Tubes va transistors (vs op amps), is there an audible difference? - Russel O. Hamm - JAES
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