I found tis circuit in na old documentation from 1958. The circuit uses germanium transistor availble that time and hard to obtain today. The circuit is indicated for phono applications using variable reluctance transducer.
An interesting application in case of needing to supply an operational amplifier or a very low...
This circuit, found in a 1958 magazine, is for reference only, since the components are not easy...
The astable multivibrator shown by the figure can produce signals in the 10 to 10 000 Hz band...