[sdiy] Potted expo converters

[Paul Maddox]

David,

> I wonder at what point a microcontroller with A/D and D/A
> conversion becomes a more effective solution for this ongoing
> problem, at least for new designs.  It seems like it could be
> made to work pretty well for control voltages and audio up to
> about 4 KHz; the sampling rate wouldn't have to be too
> unreasonable to support that well.  The actual conversion
> could probably be a lookup table for applications where
> precision isn't critical.

Given the speed of modern embedded CPUs and some of the added functionality
(some have ADC and DACs) you could do this with very little work, the
conversion could be calculated, not just a LUT as many embedded cpus run at
>10MIPs, which is more than enough to do log conversion at 4Khz..

Paul