Audio Noise Gate
The gain of the Buffer Amplifier is set by R1 and R2 where 1 kΩ ≤ R2 ≤ 10 kΩ. Resistor RROT PT sets the Rotation Point between ~ 20 mV - 1V RMS. Resistor RGATE (Noise Gate) sets the level to which the input signals are downward expanded. For 380 kΩ, the threshold will be ~ 0.7 mV. Increasing RGATE lowers the threshold. RGAIN sets the gain of the VCA between 0 dB and 20 dB. For gain = 20 dB, RGAIN = ∞; for 0 dB, RGAIN ~ 1 kW. Connect pin 12 to V+ to power down the part, else tie pin 12 to Ground.
