Variable oscillator

Although the oscillator in the diagram at first sight resembles a standard Wien bridge type, it is in fact a variant of it since it is tuned by varying only one component. This has the advantage of not needing a carefully selected stereo potentiometer; instead, a single potentiometer may be used. In the diagram, this is P1, and with values as specified, the output frequency of the oscillator may be varied between 340 Hz and 3.4 kHz.