This circuit is from a factory manual from the 80s. The circuit can be implemented with more modern operationals. Capacitor C1 is a low leakage type. The power supply must be symmetrical.
We found this circuit in the semiconductor ON manual using couplers of the time. These components...
VU or Volume Units is a sound intensity indicator that can be installed on any stereo. The...
This circuit was originally designed for medical applications and biological experiments. The...