[sdiy] Audio taper pots - shunt resistors and contact resistance

[David G Dixon]

> Some people may worry about noise from a digital circuit (for 
> example through stray capacitance) and may want to keep them 
> apart. It may also be that the semiconductor processes used 
> for a typical DAC and a "high" voltage (as opposed to 3.3 V 
> or 5 V) VCA are incompatible or difficult to combine without 
> a lot of additional R&D. Feel free to prove me wrong.

2164 VCAs are at unity gain at 0V, and are more or less completely off (-110
dB) at +3.3V.  Hence, the range is just about perfectly suited to a 0 to
3.3V digital circuit.