This circuit was found in a1980s Motorola documentation. The integrated circuit is from that time. The frequency depends on the crystal.
This circuit was found in an English magazine from 1979. The magazine no longer exists, but the...
The preamplifier using JFET presets a high input impedance and very low distortion. The input...
The values of the components of this Mullard (Philips) circuit depend on the desired voltages. The...