Study of SSI2140 Q VCA function (Patreon)

Supplemental video for SSI2140 VCF.

One of the useful features of the SSI2140 VCF IC is the Q VCA.

Transistor ladder VCFs have the problem that when the resonance is increased, the amplitude of the original audio becomes smaller.

By using Q VCA, the problem of reduced amplitude can be avoided.

The sensitivity of Q VCA can be tuned by the resistance value. The video shows how it behaves when tuned.

When the resistance is appropriate, the amplitude remains constant even when the resonance is increased.

With an inappropriate value, the amplitude will decrease or increase.