[sdiy] using a dac as a digitally controlled amplifier

[Benjamin Tremblay]

Is there any practical application for synthesizers to pass an analog signal in as a reference voltage to a DAC?
12 bit DACs are pretty cheap these days, but VCAs aren’t expensive either. 
Aside from cost, why would I want to use a DAC as a “DCA”? 

I can imagine making a state variable filter using a dual DAC as the ‘gain' stages.  
It’s the kind of thing I would try just to see how well it worked… 
 
I suppose you inject one or more DACs into an oscillator to directly control pitch and waveform, some kind of DCO where stability and simplicity are cost-effective.