We found this circuit in a 1969 Mullard documentation. The same configuration appears elsewhere in this section. The control range is -2 dB to 19.5 dB at 30 Hz.
This circuit uses only two general purpose transistors and can be powered by the circuit under...
Found in an 80's Elektor, this circuit can use any equivalent optical coupler. The buzzer is of the...
This 3-step level indicator uses only passive components. LEDs are common and trimpots can be 4k7...