Input sensitivity of a few uV and output of a few volts. Bandwidth 20Hz-300Khz so its well in the AM radio frequency range and its viable for use. Yeah it will be simpler to make a regenerative amp but this will also work even well (provided very low noise transistors are being used like bc550). Just use a well shielded casing and well grounded leads and you should be fine. In its current form you'll be able to pick all the AM frequencies at once (been there done that) so you'll definitely need a tuning circuit. A detector stage might not be needed because every preamp stage here will also act as a demodulator. So just a tuning circuit will be needed
