Alfa Rpar - AS3365D - Multi functional VCA blocks (Fader/Panner)

AS3365 contains three VCA blocks, which are intended for use in musical synthesizer applications (VCA blocks, faders, panners, multiplexers, ring modulators etc.). VCA1 and VCA2 implement function of controlling amplification. A direct signal CVMix1 is supplied to the VCA1 control, an inverted CVMix2 signal is supplied to the VCA2 control. Using two amplifiers VCA1 and VCA2 together, you can implement the function of stereo panning of the input signal. Additional control input Vcntrl controls attenuation of output current - thus realizing function of double multiplication input signal on two control signals. VCA3 block has additional feature – possibility of control/mixing of two input signals.
Vast opportunities in designing new synth solutions:
    ♦ panner and crossfader designs can use the same single CV signal, because the CV input on VCA2 works in the inverse direction of the CV input on VCA1;
    ♦ possibility to use the four-quadrant VCA3 to generate a correction curve for equal loudness (RMS) panning and fading;
    ♦ voltage controlled processing and inversion of control voltage signals, like envelope and LFO signals;
    ♦ when signal inputs are DC-coupled then both audio signals and low frequency modulation CV signals can be processed with the same circuit;
    ♦ normalization on audio input and output connectors can switch between a panning or a crossfading function, depending on how signals are plugged in.

Features:
• “Linear replacement” – “pin compatible” to AS2164
• Exceptionally low control feedthrough without trimming: 10mV maximum out of 10 V.P.P. output
• Low noise: -110 dB typical
• Summing node signal Inputs
• Current outputs capable of swinging to within 1,5V of each supply
• Control voltages referenced to ground
• Wide supply range: ±3 to ±12V or +15, - 3 to - 9 V

Applications:
• Voltage controlled mixing for audio mixers and music synthesizers: crossfading, panning, ring modulation, stereo panning, audio switching, control signal processing, audio compression with side-chain function, etc.
• for electronic music