This circuit is placed between the instrument pickup and the amplifier input. The same version can be found from other sources in this section. This is from an English magazine from the 80s.
Indicated for activation by microcontrollers, this circuit was found in the Radio Electronics...
We found this circuit in an English publication in 1991. The circuit can be assembled with...
This tuner circuit was found in an old English documentation. The JFET can be any general purpose...