This amplifier was found in Burr-Brown documentation from the 90's. The gain can be programmed by resistor Rg as per the table given in the diagram. The power supply must be symmetrical.
Based on the 4017 integrated circuit, this circuit of a European 303 Circuits from the 90s,...
This circuit has tone control, and its power depends on the supply voltage. The circuit is from...
Based on an Analog Devices LTC1540, this circuit consumes only 50 uA, serving to monitor the...