This is a combined circuit of tone generator and preamplifier. We found it in a 1975 documentation. Operational amplifiers of that time can be replaced by modern equivalents.
The time constant for this circuit found in a 1973 publication is given by R and C. The shot is...
Used with old projector films, this circuit found in Signalite documentation from the 1980s,...
This circuit generates damped sounds imitating a drum or other percussion instrument with...