This is my replacement of the original Elektor Formant COM module. I discarded the original circuitry because of the TL085 used with his unusual pinout and the availability of dedicated audio operational amplifiers. I used a more effective filter implementation for tone control. A mixer front end with four external inputs is added to make patching easier. A optional level indicator makes it easier to find the right volume level for best SNR. The maximum output volume is adjustable to protect your PA.
Specs and features
- Four additional inputs
- Maximum output volume adjustable
- Bass, middle and treble tone control
- Level indicator
- Runs on +/-15V and +/-12V (with minor resistor value changes)
- Schematic VCA
- Download docs
Nothing special in this schematic. The tone control is a Baxandall type.
- Adjust the maximum output volume with TR5.